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C/C++ Source or Header  |  1998-03-12  |  88.7 KB  |  2,896 lines
  1. //-----------------------------------------------------------------------------
  2. // Microsoft OLE DB QURYDEMO Sample
  3. // Copyright (C) 1995-1998 Microsoft Corporation
  4. //
  5. // @doc
  6. //
  7. // @module QUERY.CPP
  8. //
  9. //-----------------------------------------------------------------------------------
  10. /*
  11.     PROGRAM: QURYDEMO
  12.     ========
  13.  
  14.     PURPOSE:
  15.     ========    
  16.     demonstrates a simple MDI (Multiple Document Interface)application
  17.     that allows a user to simultaneously connect to multiple
  18.     hetrogeneous databases and perform SQL queries to get results.
  19.  
  20.     FUNCTIONS:
  21.     ==========
  22.     InitEnvironment() - Initialize OLE
  23.     DisplayProviders() - Display available Providers
  24.     ConnectDatabase() - Connect to a specific data source
  25.     DisplayConnections() - Display List of made connections
  26.     DisplayICommands() - Display list of ICommands
  27.     NewICommandWindow() - Open a new ICommand and update displays
  28.     ChangeCurrentCursor() - Change current cursor display
  29.     ChangeCurrentICommand() - Change current ICommand display
  30.     DisplayNewCrsrAndICommand() - update cusor & ICommand displays
  31.     FreeConnect() - free a IDBCreateCommand
  32.     FreeICommand() - free a ICommand
  33.     CloseICommandWindow() - close a ICommand window
  34.     ExecuteQuery() - execute a user specified query
  35.     CloseIDBCreateCommand() - check if all connections are closed
  36.     FreeEnvironment() - free OLE
  37.     ExecuteCommand() - Execute the ICommand and return an IRowset 
  38.     GetDataFromRowset() - Get the Data from the IRowset
  39.     SetupBindings() - Set the binding structure
  40.     CreateAccessor() - Create Accessor to store the Data
  41.     GetData() - Get the Data out of the rowset
  42.      
  43.  
  44.     COMMENTS:
  45.     =========
  46.     Created by Microsoft Corporation.
  47.     
  48.     The application uses MDI Child Window Titles to store values of
  49.     PROVIDER's and Command Objects. These values are also stored in the
  50.     comboboxes that are displayed on the toolbar.
  51.  
  52. */
  53. #define STRICT
  54. #define DBINITCONSTANTS
  55. #define INITGUID
  56.  
  57. #include <stdio.h>
  58. #include <string.h>
  59. #include <windows.h>
  60. #include <stddef.h>                // offsetof
  61. #include <assert.h>                // assert
  62.  
  63. #include "oledb.h"
  64. #include "oledberr.h"
  65. #include "msdaguid.h"
  66.  
  67. #include "qurydemo.h"  
  68.  
  69. // Globals
  70. extern HWND            hWndFrame;                 // Main Frame Window handle
  71. extern HWND            hWndCrsrList;            // hdbc(s) combobox on the tool bar
  72. extern HWND            hWndStmtList;            // hstmt(s) combobox on the tool bar
  73. extern HWND            hWndMDIClient;            // MDI Client window handle
  74. extern HWND            hWndActiveChild;        // Current active MDI Child window
  75. extern HINSTANCE    hAppInstance;            // Application instance
  76.  
  77. IMalloc*             g_pIMalloc = NULL;
  78.  
  79. int                    nChildCount;                    // Number of child windows currently open
  80. char                szDispBuffer[MAXDISPLAYSIZE+10];// Display Buffer
  81. unsigned char        rgbData[MAX_COL][MAXDATALEN];    // Results Data Array
  82. long                 dwDataLen[MAX_COL];                // Results Data Length Array
  83.  
  84. //char                szErrorDescription [MAXDISPLAYSIZE+1];
  85. //char                szErrorSource      [MAXDISPLAYSIZE+1];
  86.  
  87. //Variables and constants used for provider enumeration
  88. //#define   MAX_VALUE_NAME          300
  89. //#define   MAX_PROVIDER_NUM        10
  90. #define NUMELEM(p1) (sizeof(p1) / sizeof(p1[0]))
  91. #define COLUMN_ALIGNVAL 8
  92. #define ROUND_UP( Size, Amount ) (((DWORD)(Size) +  ((Amount) - 1)) & ~((Amount) - 1))
  93.  
  94. const ULONG    DEF_SOURCES_CBMAXLEN    = 64;
  95. const ULONG MAX_NUM_PROVIDERS        = 16;
  96.  
  97. IParseDisplayName*    g_pIParse = NULL;
  98. ULONG    g_cProvNames;
  99. CHAR    g_rgszProvName[MAX_NUM_PROVIDERS][DEF_SOURCES_CBMAXLEN];
  100. WCHAR    g_rgwszParseName[MAX_NUM_PROVIDERS][DEF_SOURCES_CBMAXLEN];
  101.  
  102. /*
  103.     FUNCTION: InitEnvironment()
  104.     COMMENTS: Allocate an environment handle for OLE function calls.
  105. */
  106. FAR PASCAL InitEnvironment()
  107. {
  108.     HRESULT        hr;
  109.  
  110.     // Initialize OLE
  111.     hr = CoInitialize( NULL );
  112.  
  113.     if (FAILED(hr))
  114.     {
  115.         DumpErrorHResult( hr, (LPSTR)"CoInitialize FAILED!!" );
  116.         return FALSE;
  117.     }
  118.  
  119.     // Retrieve the task memory allocator
  120.     hr = CoGetMalloc( MEMCTX_TASK, &g_pIMalloc );
  121.  
  122.     if (FAILED(hr))
  123.     {
  124.         DumpErrorHResult( hr, (LPSTR)"CoGetMalloc FAILED!!" );
  125.         return FALSE;
  126.     }
  127.  
  128.     // reset child window count
  129.     nChildCount = 0;
  130.     
  131.     // Return TRUE
  132.     return TRUE;
  133. }
  134.  
  135. /*
  136.     FUNCTION: DisplayProviders(HWND hWnd)
  137.     COMMENTS: Display a list of available Providers.
  138. */
  139. void FAR PASCAL DisplayProviders(HWND hWnd)
  140. {
  141.     ULONG        iProv;
  142.     HRESULT        hr;
  143.  
  144.     // Initialize count of provider names
  145.     g_cProvNames = 0;
  146.  
  147.     //Go to registry and get me the provider names
  148.     hr = EnumerateProviders();  
  149.     if (FAILED (hr))
  150.     {
  151.       MessageBox(hWndFrame, 
  152.                  "There was an error retrieve providers from the OLE DB Enumerator", 
  153.                  "Enumeration Error", 
  154.                  MB_OK | MB_ICONERROR);
  155.       return;
  156.     }
  157.  
  158.     //All returned Providerss in the provided combo box for display.
  159.     SendMessage(hWnd, CB_RESETCONTENT, 0, 0);
  160.     for (iProv=0; iProv<g_cProvNames; iProv++)
  161.        SendMessage(hWnd, CB_ADDSTRING, 0, (LPARAM)(LPSTR)g_rgszProvName[iProv]);
  162.  
  163.     SendMessage(hWnd, CB_SETCURSEL, 0, 0);
  164. }
  165.  
  166. /*
  167.     FUNCTION: EnumerateProviders
  168.     COMMENTS: Display a list of available providers
  169. */
  170. HRESULT EnumerateProviders
  171.     (
  172.     )
  173. {
  174.     HRESULT                hr;
  175.     ULONG                ul, cRows = 0;
  176.     ISourcesRowset*        pISrcRowset = NULL;
  177.     IRowset*            pIRowset = NULL;
  178.     IAccessor*            pIAccessor = NULL;
  179.     BYTE*                pData = NULL;
  180.     DWORD                dwOffset;
  181.     HACCESSOR            hAccessor = NULL;
  182.     DBBINDING            rgBind[3];
  183.     HROW                rghRows[MAX_NUM_PROVIDERS];
  184.     HROW*                pRows = &rghRows[0];
  185.  
  186.     enum enumSOURCES_COLUMNS {
  187.         eid_SOURCES_NAME = 1,
  188.         eid_SOURCES_PARSENAME,
  189.         eid_SOURCES_DESCRIPTION,
  190.         eid_SOURCES_TYPE,
  191.         eid_SOURCES_ISPARENT,
  192.         eid_SOURCES_CLSID,
  193.         };
  194.  
  195.     static struct tagSOURCES
  196.     {
  197.         ULONG    iOrdinal;
  198.         DBTYPE    wType;
  199.         ULONG    cbMaxLen;    
  200.     } s_rgSources[] = {
  201.         eid_SOURCES_NAME,        DBTYPE_STR,        DEF_SOURCES_CBMAXLEN,
  202.         eid_SOURCES_PARSENAME,    DBTYPE_WSTR,    DEF_SOURCES_CBMAXLEN * sizeof(WCHAR),
  203.         eid_SOURCES_TYPE,        DBTYPE_UI4,        sizeof(ULONG),
  204.     };
  205.     
  206.     memset(rghRows, 0, sizeof(rghRows));
  207.  
  208.     // Initialize the OLE DB Enumerator
  209.     if( FAILED(hr = CoCreateInstance(CLSID_OLEDB_ENUMERATOR, NULL, 
  210.         CLSCTX_INPROC_SERVER, IID_ISourcesRowset, (LPVOID*)&pISrcRowset)) )
  211.     {
  212.         DumpErrorHResult( hr, (LPSTR)"CoCreateInstance FAILED!!" );
  213.         goto EXIT;
  214.     }
  215.  
  216.     // Retrieve the Rowset
  217.     if( FAILED(hr = pISrcRowset->GetSourcesRowset(NULL, IID_IRowset, 0, NULL, 
  218.         (IUnknown**)&pIRowset)) )
  219.     {
  220.         DumpErrorHResult( hr, (LPSTR)"GetSourcesRowset FAILED!!" );
  221.         goto EXIT;
  222.     }
  223.  
  224.     memset(rgBind, 0, sizeof(rgBind));
  225.  
  226.     if( FAILED(hr = pIRowset->QueryInterface(IID_IAccessor, (LPVOID*)&pIAccessor)) )
  227.     {
  228.         DumpErrorHResult( hr, (LPSTR)"QI of IID_IAccessor from pIRowset failed" );
  229.         goto EXIT;
  230.     }
  231.  
  232.     dwOffset = 0;
  233.     for(ul=0; ul< NUMELEM(s_rgSources); ul++)
  234.     {
  235.         rgBind[ul].dwPart        = DBPART_VALUE | DBPART_LENGTH | DBPART_STATUS;
  236.         rgBind[ul].eParamIO        = DBPARAMIO_NOTPARAM;
  237.         rgBind[ul].iOrdinal        = s_rgSources[ul].iOrdinal;
  238.         rgBind[ul].wType        = s_rgSources[ul].wType;
  239.         rgBind[ul].obValue        = dwOffset + offsetof(COLUMNDATA,bData);
  240.         rgBind[ul].obLength        = dwOffset + offsetof(COLUMNDATA,dwLength);
  241.         rgBind[ul].obStatus        = dwOffset + offsetof(COLUMNDATA,wStatus);
  242.         rgBind[ul].cbMaxLen        = s_rgSources[ul].cbMaxLen;
  243.         rgBind[ul].dwMemOwner    = DBMEMOWNER_CLIENTOWNED;
  244.         dwOffset += rgBind[ul].cbMaxLen + offsetof( COLUMNDATA, bData );
  245.         dwOffset = ROUND_UP( dwOffset, COLUMN_ALIGNVAL );
  246.     }
  247.  
  248.     if( FAILED(hr = pIAccessor->CreateAccessor(DBACCESSOR_ROWDATA, NUMELEM(s_rgSources), 
  249.         rgBind, dwOffset, &hAccessor, NULL)) )
  250.     {
  251.         DumpErrorHResult( hr, (LPSTR)"Accessor Creation failed!!" );
  252.         goto EXIT;
  253.     }
  254.  
  255.     // Retrieve the providers
  256.     if( SUCCEEDED(hr = pIRowset->GetNextRows(NULL, 0, MAX_NUM_PROVIDERS, &cRows, &pRows)) )
  257.     {
  258.         // Allocate block of memory to retrieve the row data into.
  259.         pData = new BYTE[dwOffset];
  260.         if( pData == NULL )
  261.         {
  262.             DumpErrorHResult( E_OUTOFMEMORY, (LPSTR)"Unable to allocate memory for buffer");
  263.             goto EXIT;
  264.         }
  265.  
  266.         // Loop over the rows of data, collecting providers and discarding 
  267.         // enumerators..
  268.         for(ul=0; (ul<cRows) && (ul<MAX_NUM_PROVIDERS); ul++)
  269.         {
  270.             memset(pData, 0, dwOffset);
  271.  
  272.             if( SUCCEEDED(hr = pIRowset->GetData(rghRows[ul], hAccessor, pData)) )
  273.             {
  274.                 if( *((ULONG*)(pData + rgBind[2].obValue)) == DBSOURCETYPE_DATASOURCE )
  275.                 {
  276.                     // Store Provider Name
  277.                     strcpy(g_rgszProvName[g_cProvNames], (CHAR*)(pData + rgBind[0].obValue));
  278.                     
  279.                     // Store Parse Name
  280.                     wcscpy(g_rgwszParseName[g_cProvNames], (WCHAR*)(pData + rgBind[1].obValue));
  281.                     
  282.                     g_cProvNames++;
  283.                 }
  284.             }
  285.         }
  286.     }
  287.     else
  288.     {
  289.         DumpErrorHResult( hr, (LPSTR)"GetNextRows failed to retrieve Providers" );
  290.         goto EXIT;
  291.     }
  292.  
  293.     // Retrieve the IID_IParseDisplayName interface before returning
  294.     if( FAILED(hr = pISrcRowset->QueryInterface(IID_IParseDisplayName, (LPVOID*)&g_pIParse)) )
  295.     {
  296.         DumpErrorHResult( hr, (LPSTR)"QI for IParseDisplayName failed");
  297.         goto EXIT;
  298.     }
  299.  
  300. EXIT:
  301.     if( pData )
  302.         delete[] pData;
  303.  
  304.     if( pIAccessor )
  305.     {
  306.         if( hAccessor )
  307.         {
  308.             if( FAILED(hr = pIAccessor->ReleaseAccessor(hAccessor, NULL)) )
  309.                 DumpErrorHResult( hr, (LPSTR)"Release Accessor failed!!" );
  310.         }
  311.         pIAccessor->Release();
  312.     }
  313.  
  314.     if( pIRowset )
  315.     {
  316.         if( cRows )
  317.         {
  318.             if( FAILED(hr = pIRowset->ReleaseRows(cRows, rghRows, NULL, NULL, NULL)) )
  319.                 DumpErrorHResult( hr, (LPSTR)"Release of Row handles failed");
  320.         }
  321.         pIRowset->Release();
  322.     }
  323.  
  324.     if( pISrcRowset )
  325.         pISrcRowset->Release();
  326.     return hr;
  327. }
  328.  
  329.  
  330. //**********************************************************************
  331. // 
  332. // ConnectDatabase
  333. // 
  334. // Purpose:
  335. // 
  336. //     Initializes the PROVIDER and creates a IDBCreateCommand Object.
  337. //     
  338. // Parameters:
  339. //
  340. //     HWND             hWnd                - handle to the window
  341. // 
  342. // Return Value:
  343. //     TRUE         - Success
  344. //     FALSE        - Failure
  345. // 
  346. // Function Calls:
  347. //     Function                    Location
  348. // 
  349. //     IDBInitialize::Release      provider's Command object
  350. // 
  351. //     
  352. // Comments:      
  353. // 
  354. // 
  355. //**********************************************************************
  356. BOOL FAR PASCAL ConnectDatabase(HWND hWnd)
  357. {
  358.     // Global IDBInitialize Options
  359.     IMoniker*            pIMoniker            = NULL;    // Moniker
  360.     IDBInitialize *     pIDBInit            = NULL;    // IDBInitialize Object
  361.     IDBCreateCommand *    pIDBCreateCommand    = NULL;    // IDBCreateCommand
  362.     IDBCreateSession *    pIDBCreateSession    = NULL; // IDBCreateSession
  363.     IDBProperties*        pIDBProperties        = NULL; // IDBProperties
  364.     IOpenRowset *        pIOpenRowset        = NULL;    // IOpenRowset
  365.     IUnknown *            pIUnknown            = NULL;    // IUnknown
  366.     HRESULT                hr;                            // HRESULT
  367.     DBPROPSET            rgPropertySet[1];            // Array of property sets
  368.     DBPROP                rgProperties[5];            // Array of property values
  369.     BOOL                bReturn = FALSE;            // Return Value
  370.     short                iPrompt = 0;                // DBPROP_INIT_PROMPT value.
  371.     ULONG                iProp, iPDex;
  372.     ULONG                chEaten;
  373.  
  374.     // Strings for MSDASQL (CHAR & WCHAR)
  375.     CHAR                szProvName[MAXBUFLEN+1];    // Provider String
  376.     CHAR                szDBName[MAXBUFLEN+1];        // DSN String
  377.     WCHAR                wszBuff[MAXBUFLEN+1];        // WCHAR buffer
  378.     CHAR                szUserName[MAXBUFLEN+1];    // User Name
  379.     CHAR                szPassword[MAXBUFLEN+1];    // Password
  380.     CHAR                szBuffer[MAXBUFLEN+1];        // String Buffer
  381.     LRESULT             nResult;                    // Return Code
  382.     BOOL                fCommandWindow=FALSE;        // Flag to indicate Command support
  383.  
  384.     // Initialize Property Buffers
  385.     for(iProp=0; iProp<NUMELEM(rgProperties); iProp++)
  386.         VariantInit(&(rgProperties[iProp].vValue));
  387.  
  388.     // check if enough windows are already open, refuse connection
  389.     if (nChildCount >= MAXCHILDWNDS)
  390.     {
  391.         MessageBox(hWndFrame, MAXCHILDEXCEEDED, MAXCHLDERR, MB_OK | MB_ICONHAND);
  392.         return (FALSE);
  393.     }
  394.  
  395.     // Retrieve Provider values from the connect dialog box
  396.     GetDlgItemText(hWnd, IDCOMBO_PROVIDER, szProvName, MAXBUFLEN);
  397.     GetDlgItemText(hWnd, IDCOMBO_NAME,        szDBName,   MAXBUFLEN);
  398.     GetDlgItemText(hWnd, IDTEXT_USERID,    szUserName, MAXBUFLEN);
  399.     GetDlgItemText(hWnd, IDTEXT_PASSWORD,  szPassword, MAXBUFLEN);
  400.     if ((iPrompt = (short) SendMessage(GetDlgItem(hWnd, IDCOMBO_PROMPT), CB_GETCURSEL, 0, 0)) == CB_ERR)
  401.         iPrompt = 0;
  402.  
  403.     //Determine the ParseDisplayName
  404.     for(iPDex=0; iPDex<g_cProvNames; iPDex++)
  405.     {
  406.         if( strcmp((const char *)szProvName, (const char *) g_rgszProvName[iPDex])==0 )
  407.             break;
  408.     }
  409.  
  410.     if( iPDex >= g_cProvNames )
  411.     {
  412.         DumpErrorHResult( E_FAIL, (LPSTR)"Unknown Provider, Please Select Valid Provider" );
  413.         goto error;
  414.     }
  415.         
  416.     if( FAILED(hr = g_pIParse->ParseDisplayName(NULL, g_rgwszParseName[iPDex], &chEaten, &pIMoniker)) ) 
  417.     {
  418.         DumpErrorHResult( hr, (LPSTR)"ParseDisplayName failed");
  419.         goto error;
  420.     }
  421.  
  422.     if( FAILED(hr = BindMoniker(pIMoniker, 0, IID_IDBInitialize, (LPVOID*)&pIDBInit)) )
  423.     {
  424.         DumpErrorHResult( hr, (LPSTR)"BindMoniker failed");
  425.         goto error;
  426.     }
  427.  
  428.     iProp = 0;
  429.     // If DataSource name specified, then create property node
  430.     if( *szDBName != '\0' )
  431.     {
  432.         // Fill in Data Source
  433.         rgProperties[iProp].dwPropertyID        =    DBPROP_INIT_DATASOURCE;
  434.         rgProperties[iProp].dwOptions            =    DBPROPOPTIONS_REQUIRED;
  435.         rgProperties[iProp].colid                =    DB_NULLID;
  436.         MultiByteToWideChar(CP_ACP, 0, szDBName, -1, wszBuff, MAXBUFLEN+1);
  437.         V_VT(&(rgProperties[iProp].vValue))        =    VT_BSTR;
  438.         V_BSTR(&(rgProperties[iProp].vValue))    =    SysAllocString(wszBuff);
  439.         iProp++;
  440.     }
  441.  
  442.     // If User Name specified, then create property node
  443.     if( *szUserName != '\0' )
  444.     {
  445.         rgProperties[iProp].dwPropertyID    =    DBPROP_AUTH_USERID;
  446.         rgProperties[iProp].dwOptions            =    DBPROPOPTIONS_REQUIRED;
  447.         rgProperties[iProp].colid                =    DB_NULLID;
  448.         MultiByteToWideChar(CP_ACP, 0, szUserName, -1, wszBuff, MAXBUFLEN+1);
  449.         V_VT(&(rgProperties[iProp].vValue))        =    VT_BSTR;
  450.         V_BSTR(&(rgProperties[iProp].vValue))    =    SysAllocString(wszBuff);
  451.         iProp++;
  452.     }
  453.  
  454.     // If Password specified, then create property node
  455.     if( *szPassword != '\0' )
  456.     {
  457.         rgProperties[iProp].dwPropertyID    =    DBPROP_AUTH_PASSWORD;
  458.         rgProperties[iProp].dwOptions            =    DBPROPOPTIONS_REQUIRED;
  459.         rgProperties[iProp].colid                =    DB_NULLID;
  460.         MultiByteToWideChar(CP_ACP, 0, szPassword, -1, wszBuff, MAXBUFLEN+1);
  461.         V_VT(&(rgProperties[iProp].vValue))        =    VT_BSTR;
  462.         V_BSTR(&(rgProperties[iProp].vValue))    =    SysAllocString(wszBuff);
  463.         iProp++;
  464.     }
  465.  
  466.     // Set prompt level if one was given.
  467.     if (iPrompt)
  468.     {
  469.         rgProperties[iProp].dwPropertyID    =    DBPROP_INIT_PROMPT;
  470.         rgProperties[iProp].dwOptions            =    DBPROPOPTIONS_REQUIRED;
  471.         rgProperties[iProp].colid                =    DB_NULLID;
  472.         rgProperties[iProp].vValue.vt            = VT_I2;
  473.         rgProperties[iProp].vValue.iVal            = iPrompt;
  474.         iProp++;
  475.  
  476.         rgProperties[iProp].dwPropertyID    =    DBPROP_INIT_HWND;
  477.         rgProperties[iProp].dwOptions            =    DBPROPOPTIONS_REQUIRED;
  478.         rgProperties[iProp].colid                =    DB_NULLID;
  479.         rgProperties[iProp].vValue.vt            = VT_I4;
  480.         rgProperties[iProp].vValue.lVal            = (long) hWnd;
  481.         iProp++;
  482.     }
  483.  
  484.     if( iProp )
  485.     {
  486.         // Identify Property Set
  487.         rgPropertySet[0].rgProperties        =    rgProperties;
  488.         rgPropertySet[0].cProperties        =    iProp;
  489.         rgPropertySet[0].guidPropertySet    =    DBPROPSET_DBINIT;
  490.  
  491.         // from the DataSource Object get the Session Object
  492.         hr = pIDBInit->QueryInterface( 
  493.                             IID_IDBProperties, 
  494.                             (void**)&pIDBProperties );
  495.         if (FAILED(hr))
  496.         {
  497.             GetDetailedErrorInfo(hr, pIDBInit, IID_IDBInitialize, "QI for IDBProperties FAILED!!");
  498.             goto error;
  499.         }
  500.  
  501.         // Set Connection Properties
  502.         hr = pIDBProperties->SetProperties(1, rgPropertySet);
  503.         if (FAILED(hr))
  504.         {
  505.             GetDetailedErrorInfo(hr, pIDBProperties, IID_IDBProperties, "IDBProperties->SetProperties FAILED!!");
  506.             goto error;
  507.         }
  508.     } 
  509.  
  510.      // Initialize the PROVIDER
  511.     if( FAILED(hr = pIDBInit->Initialize()) )
  512.     {
  513.         GetDetailedErrorInfo(hr, pIDBInit, IID_IDBInitialize, "IDBInit->Initialize FAILED!!");
  514.         goto error;
  515.     }
  516.  
  517.     // from the DataSource Object get the Session Object
  518.     if( FAILED(hr = pIDBInit->QueryInterface( 
  519.                         IID_IDBCreateSession, 
  520.                         (void**)&pIDBCreateSession)) )
  521.     {
  522.         GetDetailedErrorInfo(hr, pIDBInit, IID_IDBInitialize, "QI for IDBCreateSession FAILED!!");
  523.         goto error;
  524.     }
  525.  
  526.     // from the Session object, attempt to get an IUnknown
  527.     if( FAILED(hr = pIDBCreateSession->CreateSession(NULL, IID_IUnknown, (IUnknown**)&pIUnknown)) )
  528.     {
  529.         GetDetailedErrorInfo(hr, pIDBCreateSession, IID_IDBCreateSession, "IDBCreateSession->CreateSession FAILED!!");
  530.         goto error;
  531.     }
  532.  
  533.     // from the Session object, attempt to get the IDBCreateCommand interface
  534.     if( FAILED(hr = pIUnknown->QueryInterface(
  535.                         IID_IDBCreateCommand, 
  536.                         (void**)&pIDBCreateCommand)) )
  537.     {
  538.         // if no Command object support, attempt to get the IOpenRowset interface
  539.         hr = pIUnknown->QueryInterface(
  540.                             IID_IOpenRowset, 
  541.                             (void**)&pIOpenRowset);
  542.         if (FAILED(hr))
  543.         {
  544.             GetDetailedErrorInfo(hr, pIUnknown, IID_IUnknown, "QI for IOpenRowset FAILED!!");
  545.             goto error;
  546.         }
  547.     }
  548.     else
  549.     {
  550.         fCommandWindow = TRUE;
  551.     }
  552.  
  553.     // update the combo-box with IUnknown from Session object
  554.     wsprintf( szBuffer, PROVIDER_SESSION_FORMAT, (LPSTR)szProvName, pIUnknown );
  555.  
  556.     nResult = (UINT)SendMessage(hWndCrsrList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  557.     SendMessage(hWndCrsrList, CB_SETCURSEL, (WPARAM)nResult, 0);
  558.     SendMessage(hWndCrsrList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  559.     ChangeCurrentCursor(hWndCrsrList);
  560.     
  561.     if (fCommandWindow)
  562.     {
  563.         // Create a Command Object and its associated window.
  564.         NewICommandWindow();
  565.     }
  566.     else
  567.     {
  568.         NewIOpenRowsetWindow();
  569.     }
  570.  
  571.     bReturn = TRUE;
  572.  
  573. error:
  574.     if( pIMoniker )
  575.         pIMoniker->Release();
  576.  
  577.     // Initialize Property Buffers
  578.     for(iProp=0; iProp<NUMELEM(rgProperties); iProp++)
  579.         VariantClear(&(rgProperties[iProp].vValue));
  580.  
  581.     // If we are successully connected, and the IParse pointer
  582.     // exists release it.
  583.     if( bReturn && g_pIParse )
  584.     {
  585.         g_pIParse->Release();
  586.         g_pIParse = NULL;
  587.     }
  588.  
  589.     // Release IUnknown (for Session) on error only.
  590.     // The pointer value has been copied to the window.
  591.     if( (!bReturn) && (pIUnknown) )
  592.         pIUnknown->Release();
  593.  
  594.     if( (pIDBCreateCommand) )
  595.         pIDBCreateCommand->Release();
  596.  
  597.     if( (pIDBProperties) )
  598.         pIDBProperties->Release();
  599.  
  600.     if( (pIOpenRowset) )
  601.         pIOpenRowset->Release();
  602.  
  603.     if( pIDBCreateSession )
  604.         pIDBCreateSession->Release();
  605.  
  606.     if(pIDBInit)
  607.         pIDBInit->Release();
  608.  
  609.     return (bReturn);
  610.  
  611. } 
  612.  
  613. //**********************************************************************
  614. // 
  615. // DisplayConnections
  616. // 
  617. // Purpose:
  618. // 
  619. //     Display list of available hdbc(s) in the given list box.
  620. //     
  621. // Parameters:
  622. //
  623. //     HWND             hWndhdbc               - handle to the window
  624. // 
  625. // Return Value:
  626. // 
  627. // Function Calls:
  628. //     Function                    Location
  629. // 
  630. // 
  631. //     
  632. // Comments:      
  633. // 
  634. // 
  635. //**********************************************************************
  636. void FAR PASCAL DisplayConnections(HWND hWndhdbc)
  637. {
  638.     ULONG     nConnects;                // # of Connections
  639.     ULONG     count;                    // Count
  640.     char    szBuffer[MAXBUFLEN+1];    // String Buffer
  641.  
  642.     // Read the information from the  combo-box 
  643.     // on the tool bar and feed it in the given list box.
  644.     SendMessage(hWndhdbc, LB_RESETCONTENT, 0, 0);
  645.     nConnects = SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0);
  646.  
  647.     for (count = 0; count < nConnects; count++)
  648.     {
  649.         SendMessage(hWndCrsrList, CB_GETLBTEXT, count, (LPARAM)(LPSTR)szBuffer);
  650.         SendMessage(hWndhdbc, LB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  651.     }
  652.  
  653.     SendMessage(hWndhdbc, LB_SETCURSEL, 0, 0);
  654. }
  655.  
  656. //**********************************************************************
  657. // 
  658. // DisplayICommands
  659. // 
  660. // Purpose:
  661. // 
  662. //     Initializes the PROVIDER and creates a ICommand Object.
  663. //     Display list of ICommand Objects for the currently selected PROVIDER.
  664. //     
  665. // Parameters:
  666. //
  667. //  HWND             hWndhdbc                 - handle to the PROVIDER
  668. //     HWND             hWndhstmt                - handle to the ICommand
  669. //    int             nCrsrIndex                 - Count
  670. // 
  671. // Return Value:
  672. // 
  673. // Function Calls:
  674. //     Function                    Location
  675. // 
  676. // 
  677. //     
  678. // Comments:      
  679. // 
  680. // 
  681. //**********************************************************************
  682. void FAR PASCAL DisplayICommands(HWND hWndhstmt, HWND hWndhdbc, int nCrsrIndex)
  683. {
  684.     char                szBuffer[MAXBUFLEN+1];    // MDI child window title
  685.     HWND                hWndChild;                // MDI child window handle
  686.     IDBCreateCommand *     pIDBCreate1;            // IDBCreateCommand Object #1
  687.     IDBCreateCommand *     pIDBCreate2;            // IDBCreateCommand Object #2
  688.     ICommand *            pICommand;                // ICommand Object
  689.  
  690.     // Reset the Command list box in the disconnect dialog box
  691.     SendMessage(hWndhstmt, LB_RESETCONTENT, 0, 0);
  692.  
  693.     // Go through all available MDI child windows and check if the
  694.     // PROVIDER in the title matches the one selected in the list box.
  695.     // If they match, use the Command in the window title to create
  696.     // a new entry in the Command list box.
  697.     for (hWndChild=GetWindow(hWndMDIClient, GW_CHILD); hWndChild; hWndChild=GetWindow(hWndChild, GW_HWNDNEXT))
  698.     {
  699.         // Class name check is necessary as some of MDI child
  700.         // windows may be iconized by the user and MDIClient
  701.         // in such cases create additional windows (such as icon titles).
  702.         GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  703.         
  704.         if (strcmp(szBuffer, OLEDBMDICLASS))
  705.             continue;
  706.  
  707.         GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  708.         sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate1, &pICommand);
  709.  
  710.         SendMessage(hWndhdbc, LB_GETTEXT, (WPARAM)nCrsrIndex, (LPARAM)(LPSTR)szBuffer);
  711.         sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate2);
  712.  
  713.         if (pIDBCreate1 != pIDBCreate2)
  714.             continue;
  715.  
  716.         wsprintf(szBuffer, ((hWndChild == hWndActiveChild) ?  CURQUERY_STRING:    QUERY_STRING), pICommand);
  717.         SendMessage(hWndhstmt, LB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  718.     }
  719.     SendMessage(hWndhstmt, LB_SETSEL, TRUE, 0);
  720. }
  721.  
  722. //**********************************************************************
  723. // 
  724. // NewICommandWindow
  725. // 
  726. // Purpose:
  727. // 
  728. //     Create a new ICommand Object on the current IDBCreateCommand.
  729. //     
  730. // Parameters:
  731. // 
  732. // Return Value:
  733. // 
  734. // Function Calls:
  735. //     Function                         Location
  736. // 
  737. //       IDBCreateCommand::CreateCommand    provider's Command object
  738. //     ICommand::Release                provider's Command object
  739. //        
  740. //     
  741. // Comments:      
  742. // 
  743. // 
  744. //**********************************************************************
  745. void FAR PASCAL NewICommandWindow()
  746. {
  747.     int                 nCurrenthdbc;                // Current PROVIDER
  748.     char                szBuffer[MAXBUFLEN+1];        // String in PROVIDER ComboBox on Toolbar
  749.     char                szProvName[MAXBUFLEN+1];    // DSN String
  750.     MDICREATESTRUCT        mcs;                        // MDI Child Window Create Struc
  751.     
  752.     IDBCreateCommand *     pIDBCreateCommand    = NULL;    // IDBCreateCommand Object
  753.     IOpenRowset *         pIOpenRowset        = NULL;    // IOpenRowset Object
  754.     ICommand *            pICommand            = NULL;    // ICommand Object
  755.     ICommand *            pIUnknown            = NULL;    // IUnknown for session Object
  756.     HRESULT                hr;                            // HRESULT
  757.     BOOL                bReturn                = FALSE;// Return Value
  758.  
  759.         
  760.     // check if there is PROVIDER selected in the Combo-Box
  761.     if ((nCurrenthdbc = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0)) == CB_ERR)
  762.     {
  763.         MessageBox(hWndFrame, MAKECONNECT, NOSESSIONERROR, MB_OK | MB_ICONHAND);
  764.         return;
  765.     }
  766.     
  767.     // check if the number of windows exceeds MAXCHILDWNDS
  768.     if (nChildCount >= MAXCHILDWNDS)
  769.     {
  770.         MessageBox(hWndFrame, MAXCHILDEXCEEDED, MAXCHLDERR, MB_OK | MB_ICONHAND);
  771.         return;
  772.     }
  773.  
  774.     // Scan PROVIDER string and IDBCreateCommand value from the combo-box
  775.     SendMessage(hWndCrsrList, CB_GETLBTEXT, (WPARAM)nCurrenthdbc, (LPARAM)(LPSTR)szBuffer);
  776.     
  777.     sscanf(szBuffer, SCANPROVIDERSESSION_FORMAT, szProvName, &pIUnknown);
  778.         
  779.     // from the Session object, attempt to get the IDBCreateCommand interface
  780.     hr = pIUnknown->QueryInterface(
  781.                         IID_IDBCreateCommand, 
  782.                         (void**)&pIDBCreateCommand);
  783.     if (FAILED(hr))
  784.     {
  785.         // if no Command object support, attempt to get the IOpenRowset interface
  786.         hr = pIUnknown->QueryInterface(
  787.                             IID_IOpenRowset, 
  788.                             (void**)&pIOpenRowset);
  789.         if (FAILED(hr))
  790.         {
  791.             GetDetailedErrorInfo(hr, pIUnknown, IID_IUnknown, "QI for IOpenRowset FAILED!!");
  792.             goto error;
  793.         }
  794.     }
  795.     else
  796.     {
  797.         // Create a command object 
  798.         hr = pIDBCreateCommand->CreateCommand(NULL, IID_ICommand, (IUnknown**)&pICommand);
  799.  
  800.         if (FAILED(hr))
  801.         {
  802.            GetDetailedErrorInfo(hr, pIDBCreateCommand, IID_IDBCreateCommand, "pIDBCreateCommand->CreateCommand FAILED!!");
  803.            goto error;
  804.         }
  805.     }
  806.  
  807.         
  808.     // create a new MDI client window. maximized, if the previous is so.
  809.     mcs.szClass = OLEDBMDICLASS;
  810.     mcs.szTitle = UNTITLED;
  811.     mcs.hOwner  = hAppInstance;
  812.     mcs.style   = hWndActiveChild && IsZoomed(hWndActiveChild) ? WS_MAXIMIZE : 0;
  813.     mcs.x = mcs.cx = mcs.y = mcs.cy = CW_USEDEFAULT;
  814.     hWndActiveChild = (HWND)(UINT)SendMessage(hWndMDIClient, WM_MDICREATE, 0, (LPARAM)(LPMDICREATESTRUCT)&mcs);
  815.         
  816.     // check if it was created, if it wasn't free up resource and flag warning
  817.     if (!hWndActiveChild)
  818.     {
  819.         MessageBox(hWndFrame, CREATECHILDERR, EXECERROR, MB_OK|MB_ICONEXCLAMATION|MB_TASKMODAL);
  820.         goto error;
  821.     }
  822.         
  823.     // Display the Provider string, PROVIDER and IDBCreateCommand/IOpenRowset in the title
  824.     // of newly created window. Increment the child window counter
  825.      wsprintf(szBuffer, QUERY_STRING, pICommand);
  826.         
  827.     SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  828.     SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  829.     
  830.      wsprintf(szBuffer, PROVIDER_SESSION_COMMAND_FORMAT, (LPSTR)szProvName, pIUnknown, pICommand);
  831.     
  832.     SetWindowText(hWndActiveChild, szBuffer);
  833.     nChildCount++;
  834.     
  835.     // Update the Command Combo-Box on the tool bar.
  836.     ChangeCurrentICommand(hWndStmtList);
  837.     bReturn = TRUE;
  838.  
  839. error:
  840.     // Note that we obtained pIUnknown (Session ptr) from the window.
  841.     // So we leave it alone.
  842.  
  843.     // Release ICommand on error only.
  844.     // The pointer value has been copied to the window.
  845.     if (pICommand && !bReturn)
  846.         pICommand->Release();
  847.  
  848.     if (pIDBCreateCommand)
  849.         pIDBCreateCommand->Release();
  850.  
  851.     if (pIOpenRowset)
  852.         pIOpenRowset->Release();
  853. }
  854.  
  855.  
  856.  
  857.  
  858. //**********************************************************************
  859. // 
  860. // ChangeCurrentCursor
  861. // 
  862. // Purpose:
  863. // 
  864. //     Change the displayed PROVIDER in the PROVIDER(s) combobox.
  865. //     Also activate the appropriate MDI child window that
  866. //     has the same PROVIDER as the new PROVIDER in the combobox.
  867. //
  868. // Parameters:
  869. //
  870. //     HWND             hWndCrsrList               - handle to the window
  871. // 
  872. // Return Value:
  873. // 
  874. // Function Calls:
  875. //     Function                    Location
  876. // 
  877. // 
  878. //     
  879. // Comments:      
  880. // 
  881. // 
  882. //**********************************************************************
  883. void FAR PASCAL ChangeCurrentCursor(HWND hWndCrsrList)
  884. {
  885.     ULONG                nNewhdbc;                // New PROVIDER position
  886.     ULONG                nConnects;                // # of connections
  887.     ULONG                nCount;                    // Counter
  888.     char                szBuffer[MAXBUFLEN+1];    // String Buffer
  889.     BOOL                bChangedFocus;            // Activate different MDI child
  890.     HWND                hWndChild;                // MDI Child window
  891.     IDBCreateCommand*     pIDBCreate1;            // IDBCreateCommand #1
  892.     IDBCreateCommand*     pIDBCreate2;            // IDBCreateCommand #2
  893.     ICommand*            pICommand;                // ICommand Object
  894.  
  895.     // check to see if the current selection in the combo-box
  896.     // differs from the previous selection, if it is the same then
  897.     // simply return. Check is made by searching a marked string
  898.     // in the PROVIDER combobox.
  899.     nNewhdbc = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0);
  900.     nConnects = (int)SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0);
  901.  
  902.     for(nCount = 0; nCount < nConnects; nCount++)
  903.     {
  904.         SendMessage(hWndCrsrList, CB_GETLBTEXT, nCount, (LPARAM)(LPSTR)szBuffer);
  905.         if (strstr(szBuffer, CUR_MARK))
  906.             break;
  907.     }
  908.  
  909.     if (nCount == nNewhdbc)
  910.         return;
  911.  
  912.     // if there was a current marked hdbc in the combobox, remove the
  913.     // mark from the string and replace it in the combobox.
  914.     if (nCount != nConnects)
  915.     {
  916.         SendMessage(hWndCrsrList, CB_GETLBTEXT, nCount, (LPARAM)(LPSTR)szBuffer);
  917.         szBuffer[strlen(szBuffer)-2] = '\0';
  918.         SendMessage(hWndCrsrList, CB_INSERTSTRING, nCount, (LPARAM)(LPSTR)szBuffer);
  919.         SendMessage(hWndCrsrList, CB_DELETESTRING, nCount+1, 0);
  920.     }
  921.     
  922.     // Create a new marked string with currently selected hdbc string in
  923.     // the combobox and replace it with the original.
  924.     SendMessage(hWndCrsrList, CB_GETLBTEXT, nNewhdbc, (LPARAM)(LPSTR)szBuffer);
  925.     strcat(szBuffer, CUR_MARK);
  926.     SendMessage(hWndCrsrList, CB_INSERTSTRING, nNewhdbc, (LPARAM)(LPSTR)szBuffer);
  927.     SendMessage(hWndCrsrList, CB_DELETESTRING, nNewhdbc+1, 0);
  928.     SendMessage(hWndCrsrList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  929.  
  930.     // Reset the ICommand combobox. Search through the MDI child windows
  931.     // and collect all ICommands from window titles that have the same
  932.     // PROVIDER value as the newly selected PROVIDER in the PROVIDER(s) combo-box above.
  933.     SendMessage(hWndStmtList, CB_RESETCONTENT, 0, 0);
  934.     for (bChangedFocus=FALSE, hWndChild=GetWindow(hWndMDIClient, GW_CHILD);    hWndChild; hWndChild = GetWindow(
  935.         hWndChild, GW_HWNDNEXT))
  936.     {
  937.         // Check class name to skip iconized titles or other
  938.         // such non MDI Child windows
  939.         GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  940.         if (strcmp(szBuffer, OLEDBMDICLASS))
  941.             continue;
  942.  
  943.         GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  944.         sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate1, &pICommand);
  945.  
  946.         SendMessage(hWndCrsrList, CB_GETLBTEXT, (WPARAM)nNewhdbc, (LPARAM)(LPSTR)szBuffer);
  947.         sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate2);
  948.  
  949.         if (pIDBCreate1 != pIDBCreate2)
  950.             continue;
  951.                 
  952.         if (!bChangedFocus)
  953.         {
  954.             // If the first match is found, change the active window
  955.             // and update the ICommand(s) combobox with a new entry that
  956.             // has ICommand marked with current marker.
  957.             bChangedFocus = TRUE;
  958.             hWndActiveChild = hWndChild;
  959.             SendMessage(hWndMDIClient, WM_MDIACTIVATE, (WPARAM)hWndChild, 0);
  960.             wsprintf(szBuffer, CURQUERY_STRING, pICommand);
  961.             SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  962.             SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  963.         }
  964.         else
  965.         {
  966.             // simply add the ICommand in the ICommand(s) combobox.
  967.             wsprintf(szBuffer, QUERY_STRING, pICommand);
  968.             SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  969.         }
  970.     }
  971. }
  972.  
  973. //**********************************************************************
  974. // 
  975. // ChangeCurrentICommand
  976. // 
  977. // Purpose:
  978. // 
  979. //     Change the current selection in the ICommand(s) combobox.
  980. //     Update the current marker in the combobox and activate
  981. //     proper MDI Child window.
  982. //
  983. // Parameters:
  984. //
  985. //     HWND             hWndStmtList               - handle to the window
  986. // 
  987. // Return Value:
  988. // 
  989. // Function Calls:
  990. //     Function                    Location
  991. // 
  992. // 
  993. //     
  994. // Comments:      
  995. // 
  996. // 
  997. //**********************************************************************
  998. void FAR PASCAL ChangeCurrentICommand(HWND hWndStmtList)
  999. {
  1000.     ULONG                nNewICommand;            // New Selection in Combo-Box
  1001.     ULONG                 nICommands;                // # of ICommands
  1002.     ULONG                 nCount;                    // Counter
  1003.     char                szBuffer[MAXBUFLEN+1];    // String Buffer
  1004.     HWND                hWndChild;                // MDI Child Window Handle
  1005.     IDBCreateCommand*     pIDBCreate1;            // IDBCreateCommand Object #1
  1006.     IDBCreateCommand*     pIDBCreate2;            // IDBCreateCommand Object #2
  1007.     ICommand*            pICommand1;                // ICommand Object #1
  1008.     ICommand*            pICommand2;                // ICommand Object #2
  1009.  
  1010.     // Find the index of new selection and total number of ICommand(s)
  1011.     nNewICommand = (int)SendMessage(hWndStmtList, CB_GETCURSEL, 0, 0);
  1012.     nICommands      = (int)SendMessage(hWndStmtList, CB_GETCOUNT,  0, 0);
  1013.  
  1014.     // Check if the current selection is same as previous one, if
  1015.     // so simply return. Check for marker to determine previous selection
  1016.     for(nCount = 0; nCount < nICommands; nCount++)
  1017.     {
  1018.         SendMessage(hWndStmtList, CB_GETLBTEXT, nCount, (LPARAM)(LPSTR)szBuffer);
  1019.         if (strstr(szBuffer, CUR_MARK))
  1020.             break;
  1021.     }
  1022.  
  1023.     if (nCount == nNewICommand)
  1024.         return;
  1025.  
  1026.     // If a previous selection was found, remove current marker
  1027.     // and update it in the ICommand(s) combobox.
  1028.     if (nCount != nICommands)
  1029.     {
  1030.         SendMessage(hWndStmtList, CB_GETLBTEXT, nCount, (LPARAM)(LPSTR)szBuffer);
  1031.         szBuffer[strlen(szBuffer)-2] = '\0';
  1032.         SendMessage(hWndStmtList, CB_INSERTSTRING, nCount, (LPARAM)(LPSTR)szBuffer);
  1033.         SendMessage(hWndStmtList, CB_DELETESTRING, nCount+1, 0);
  1034.     }
  1035.     
  1036.     // Mark the current selection and update it in the ICommand(s) combobox
  1037.     SendMessage(hWndStmtList, CB_GETLBTEXT, nNewICommand, (LPARAM)(LPSTR)szBuffer);
  1038.     strcat(szBuffer, CUR_MARK);
  1039.     SendMessage(hWndStmtList, CB_INSERTSTRING, nNewICommand, (LPARAM)(LPSTR)szBuffer);
  1040.     SendMessage(hWndStmtList, CB_DELETESTRING, nNewICommand+1, 0);
  1041.     SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1042.  
  1043.     // Scan ICommand value and DSN value from current selection in
  1044.     // PROVIDER(s) and ICommand(s) comboboxes.
  1045.     sscanf(szBuffer, QUERY_STRING, &pICommand1);
  1046.     
  1047.     SendMessage( hWndCrsrList, CB_GETLBTEXT, 
  1048.                 (UINT)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0),
  1049.                 (LPARAM)(LPSTR)szBuffer);
  1050.  
  1051.     sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate1);
  1052.  
  1053.     // Go through list of MDI Child windows and match the ICommand and PROVIDER
  1054.     // values. If a match if found (must be), activate the window
  1055.     for (hWndChild=GetWindow(hWndMDIClient, GW_CHILD); hWndChild; hWndChild=GetWindow(hWndChild, GW_HWNDNEXT))
  1056.     {
  1057.         // Ignore non MDI child windows
  1058.         GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  1059.         if (strcmp(szBuffer, OLEDBMDICLASS))
  1060.             continue;
  1061.  
  1062.         GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  1063.         sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate2, &pICommand2);
  1064.  
  1065.         if (pIDBCreate1 == pIDBCreate2 && pICommand1 == pICommand2)
  1066.         {
  1067.             hWndActiveChild = hWndChild;
  1068.             SendMessage(hWndMDIClient, WM_MDIACTIVATE, (WPARAM)hWndChild, 0);
  1069.             break;
  1070.         }
  1071.     }
  1072. }
  1073.  
  1074. //**********************************************************************
  1075. // 
  1076. // DisplayNewCrsrAndICommand
  1077. // 
  1078. // Purpose:
  1079. // 
  1080. //     Change the current selection in the ICommand(s) combobox.
  1081. //     Update the current marker in the combobox and activate
  1082. //     proper MDI Child window.
  1083. //
  1084. // Parameters:
  1085. //
  1086. //     HWND             hWndStmtList               - handle to the window
  1087. // 
  1088. // Return Value:
  1089. // 
  1090. // Function Calls:
  1091. //     Function                    Location
  1092. // 
  1093. // 
  1094. //     
  1095. // Comments:      
  1096. // 
  1097. // 
  1098. //**********************************************************************
  1099. void FAR PASCAL DisplayNewCrsrAndICommand()
  1100. {
  1101.     ULONG                 nConnects;                // # of PROVIDER(s)
  1102.     ULONG                 nICommands;                // # of ICommand(s)
  1103.     ULONG                 nOldPROVIDER;                // Prev selected PROVIDER in combobox
  1104.     ULONG                nOldICommand;            // Prev selected ICommand in combobox
  1105.     ULONG                nIndex;                    // Counter
  1106.     char                szBuffer[MAXBUFLEN+1];    // String Buffer
  1107.     HWND                hWndChild;                // MDI Child Window
  1108.     IDBCreateCommand*     pIDBCreate1;            // IDBCreateCommand Object #1
  1109.     IDBCreateCommand*     pIDBCreate2;            // IDBCreateCommand Object #2
  1110.     ICommand*            pICommand1;                // ICommand Object #1
  1111.     ICommand*            pICommand2;                // ICommand Object #2
  1112.  
  1113.     // Scan PROVIDER and ICommand values from newly selected window
  1114.     GetWindowText(hWndActiveChild, szBuffer, MAXBUFLEN);
  1115.     sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate1, &pICommand1);
  1116.  
  1117.     // Search through list of PROVIDER(s) in PROVIDER combobox and find
  1118.     // matching PROVIDER. remove marker from prev selection and add
  1119.     // marker to the new selection. Update combobox accordingly.
  1120.     nConnects = (int)SendMessage(hWndCrsrList, CB_GETCOUNT,  0, 0);
  1121.     nOldPROVIDER   = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0);
  1122.  
  1123.     for(pIDBCreate2 = (IDBCreateCommand*)(nIndex = 0); pIDBCreate1 != pIDBCreate2; nIndex++)
  1124.     {
  1125.         SendMessage(hWndCrsrList, CB_GETLBTEXT, nIndex, (LPARAM)(LPSTR)szBuffer);
  1126.         sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate2);
  1127.     }
  1128.  
  1129.     // Change in PROVIDER combobox required.
  1130.     if (--nIndex != nOldPROVIDER)
  1131.     {
  1132.         SendMessage(hWndCrsrList, CB_GETLBTEXT, nOldPROVIDER, (LPARAM)(LPSTR)szBuffer);
  1133.         szBuffer[strlen(szBuffer)-2] = '\0';
  1134.         SendMessage(hWndCrsrList, CB_INSERTSTRING, nOldPROVIDER, (LPARAM)(LPSTR)szBuffer);
  1135.         SendMessage(hWndCrsrList, CB_DELETESTRING, nOldPROVIDER+1, 0);
  1136.  
  1137.         SendMessage(hWndCrsrList, CB_GETLBTEXT, nIndex, (LPARAM)(LPSTR)szBuffer);
  1138.         strcat(szBuffer, CUR_MARK);
  1139.         SendMessage(hWndCrsrList, CB_INSERTSTRING, nIndex, (LPARAM)(LPSTR)szBuffer);
  1140.         SendMessage(hWndCrsrList, CB_DELETESTRING, nIndex+1, 0);
  1141.         SendMessage(hWndCrsrList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1142.  
  1143.         // Reset the ICommand(s) combobox, search through the list
  1144.         // of MDI child windows and find all hstmt(s) associated to
  1145.         // new PROVIDER. Build the new list of ICommand(s) for the ICommand
  1146.         // combobox. Mark the one ICommand that matches the currently
  1147.         // activated MDI child window.
  1148.         SendMessage(hWndStmtList, CB_RESETCONTENT, 0, 0);
  1149.         for (hWndChild=GetWindow(hWndMDIClient,GW_CHILD);hWndChild;hWndChild=GetWindow(hWndChild,GW_HWNDNEXT))
  1150.         {
  1151.             GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  1152.             if (strcmp(szBuffer, OLEDBMDICLASS))
  1153.                 continue;
  1154.  
  1155.             GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  1156.             sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate2, &pICommand2);
  1157.  
  1158.             if (pIDBCreate1 != pIDBCreate2)
  1159.                 continue;
  1160.  
  1161.             if (hWndActiveChild == hWndChild)
  1162.             {
  1163.                 wsprintf(szBuffer, CURQUERY_STRING, pICommand2);
  1164.                 SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1165.                 SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1166.             }
  1167.             else
  1168.             {
  1169.                 wsprintf(szBuffer, QUERY_STRING, pICommand2);
  1170.                 SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1171.             }
  1172.         }
  1173.     }
  1174.     // No change in PROVIDER combobox required
  1175.     else
  1176.     {
  1177.         // Go through the list of ICommand(s) in ICommand combobox.
  1178.         // Find the one that matches the currently activated MDI child window.
  1179.         nOldICommand = (int)SendMessage(hWndStmtList, CB_GETCURSEL, 0, 0);
  1180.         nICommands = (int)SendMessage(hWndStmtList, CB_GETCOUNT, 0, 0);
  1181.  
  1182.         for(pICommand2 = (ICommand*)(nIndex = 0); pICommand1 != pICommand2; nIndex++)
  1183.         {
  1184.             SendMessage(hWndStmtList, CB_GETLBTEXT, nIndex, (LPARAM)(LPSTR)szBuffer);
  1185.             sscanf(szBuffer, QUERY_STRING, &pICommand2);
  1186.         }
  1187.  
  1188.         // New index in ICommand differs from previous selection
  1189.         if (--nIndex != nOldICommand)
  1190.         {
  1191.             // Remove the marker from previous selection.
  1192.             // Add it to the new string and update the combobox display
  1193.             SendMessage(hWndStmtList, CB_GETLBTEXT, nOldICommand, (LPARAM)(LPSTR)szBuffer);
  1194.             szBuffer[strlen(szBuffer)-2] = '\0';
  1195.             SendMessage(hWndStmtList, CB_INSERTSTRING, nOldICommand, (LPARAM)(LPSTR)szBuffer);
  1196.             SendMessage(hWndStmtList, CB_DELETESTRING, nOldICommand+1, 0);
  1197.  
  1198.             SendMessage(hWndStmtList, CB_GETLBTEXT, nIndex, (LPARAM)(LPSTR)szBuffer);
  1199.             strcat(szBuffer, CUR_MARK);
  1200.             SendMessage(hWndStmtList, CB_INSERTSTRING, nIndex, (LPARAM)(LPSTR)szBuffer);
  1201.             SendMessage(hWndStmtList, CB_DELETESTRING, nIndex+1, 0);
  1202.             SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1203.         }
  1204.     }
  1205. }
  1206.  
  1207. //**********************************************************************
  1208. // 
  1209. // FreeConnect
  1210. // 
  1211. // Purpose:
  1212. // 
  1213. //     Disconnect and Free the currently selected PROVIDER in
  1214. //     the PROVIDER listbox in disconnect dialog. Call RELEASE
  1215. //     to free the PROVIDER. Close all MDI
  1216. //     child windows associated with this PROVIDER. That will
  1217. //     automatically free associated ICommand(s).
  1218. //
  1219. // Parameters:
  1220. //
  1221. //     HWND             hWndhdbc               - handle to the window
  1222. // 
  1223. // Return Value:
  1224. // 
  1225. // Function Calls:
  1226. //     Function                    Location
  1227. // 
  1228. //     IDBCreateCommand::Release   provider's Command object
  1229. //     
  1230. // Comments:      
  1231. // 
  1232. // 
  1233. //**********************************************************************
  1234. void FAR PASCAL FreeConnect(HWND hWndhdbc)
  1235. {
  1236.     int                 nIndex;                    // Current Selection in the listbox of disconnect dlg
  1237.     int                    nCurrent;                // Current Selected PROVIDER(s) combobox
  1238.     char                szBuffer[MAXBUFLEN+1];    // String Buffer
  1239.     char                szSelect[MAXBUFLEN+1];    // Original Selected PROVIDER(s) combobox
  1240.     char                szProvName[MAXBUFLEN+1];// DSN string
  1241.     HWND                hWndChild;                // MDI Child window
  1242.     IDBCreateCommand *     pIDBCreate1;            // IDBCreateCmmand Object #1
  1243.     IDBCreateCommand *     pIDBCreate2;            // IDBCreateCmmand Object #2
  1244.     IErrorInfo *        pIErrorInfo;            // IErrorInfo Object
  1245.  
  1246.     // Check current selection in the list box of disconnect dialog. 
  1247.     // Scan PROVIDER value from the current selection.
  1248.     if ((nIndex = (int)SendMessage(hWndhdbc, LB_GETCURSEL, 0, 0)) == LB_ERR)
  1249.         return;
  1250.  
  1251.     SendMessage(hWndhdbc, LB_GETTEXT, (WPARAM)nIndex, (LPARAM)(LPSTR)szBuffer);
  1252.     sscanf(szBuffer, SCANPROVIDERSESSION_FORMAT, szProvName, &pIDBCreate1);
  1253.  
  1254.     // Go through the list of MDI child windows and find matching PROVIDER(s)
  1255.     // close all children who have the same PROVIDER value. Closing them
  1256.     // automatically frees associated ICommands. See CloseICommandWindow.
  1257.     for(hWndChild = GetWindow(hWndMDIClient, GW_CHILD); hWndChild; )
  1258.     {
  1259.         // Store next window handle before destroying the currentone
  1260.         HWND hWndTemp = GetWindow(hWndChild, GW_HWNDNEXT);
  1261.         
  1262.         // Ignore non MDI child windows
  1263.         GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  1264.         if (!strcmp(szBuffer, OLEDBMDICLASS))
  1265.         {
  1266.             GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  1267.             sscanf(szBuffer, SCANSESSION_TITLEFORMAT, &pIDBCreate2);
  1268.             if (pIDBCreate1 == pIDBCreate2)
  1269.             {
  1270.                 // Destroy the window and restart search
  1271.                 SendMessage(hWndMDIClient, WM_MDIDESTROY, (WPARAM)hWndChild, 0);
  1272.                 hWndTemp = GetWindow(hWndMDIClient, GW_CHILD);
  1273.             }
  1274.         }
  1275.         hWndChild = hWndTemp;
  1276.     }
  1277.  
  1278.     // Release the Command Object & return
  1279.     if( pIDBCreate1 )
  1280.         pIDBCreate1->Release();
  1281.  
  1282.     // Release any remaining error objects.  This is idempotent.
  1283.     // Otherwise the provider might have an outstanding global-object count.
  1284.     GetErrorInfo( 0, &pIErrorInfo );
  1285.     if (pIErrorInfo)
  1286.         pIErrorInfo->Release();
  1287.  
  1288.     // Unload any DLL's no longer being used
  1289.     CoFreeUnusedLibraries();
  1290.         
  1291.     // Update the PROVIDER(s) combobox display by removing the deleted PROVIDER
  1292.     // from the list and reselecting the previous selection
  1293.     wsprintf(szBuffer, PROVIDER_SESSION_FORMAT, (LPSTR)szProvName, pIDBCreate1);
  1294.     nCurrent = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0);
  1295.     SendMessage(hWndCrsrList, CB_GETLBTEXT, nCurrent, (LPARAM)(LPSTR)szSelect);
  1296.     nIndex = (int)SendMessage(hWndCrsrList, CB_FINDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  1297.     SendMessage(hWndCrsrList, CB_DELETESTRING, (WPARAM)nIndex, 0);
  1298.     SendMessage(hWndCrsrList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szSelect);
  1299.     
  1300.     // If there is no query window open and the current selected PROVIDER
  1301.     // was deleted, make sure to make the next available PROVIDER as current
  1302.     if (SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0) &&
  1303.         !GetWindow(hWndMDIClient, GW_CHILD) && (nCurrent == nIndex))
  1304.     {
  1305.         if ((nCurrent = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0))!=CB_ERR)
  1306.             return;
  1307.         SendMessage(hWndCrsrList, CB_GETLBTEXT, 0, (LPARAM)(LPSTR)szSelect);
  1308.         strcat(szSelect, CUR_MARK);
  1309.         SendMessage(hWndCrsrList, CB_INSERTSTRING, 0, (LPARAM)(LPSTR)szSelect);
  1310.         SendMessage(hWndCrsrList, CB_DELETESTRING, 1, 0);
  1311.         SendMessage(hWndCrsrList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szSelect);
  1312.     }
  1313. }
  1314.  
  1315. //**********************************************************************
  1316. // 
  1317. // FreeICommand
  1318. // 
  1319. // Purpose:
  1320. // 
  1321. //     Free a ICommand window based upon current selection in
  1322. //     ICommand list box in the disconnect dialog.
  1323. //
  1324. // Parameters:
  1325. //
  1326. //     HWND             hWndhstmt               - handle to the window
  1327. //     HWND             hWndhdbc                - handle to the window
  1328. //  int             nIndex                    - Index
  1329. // 
  1330. // Return Value:
  1331. // 
  1332. // Function Calls:
  1333. //     Function                    Location
  1334. // 
  1335. // 
  1336. //     
  1337. // Comments:      
  1338. // 
  1339. // 
  1340. //**********************************************************************
  1341. void FAR PASCAL FreeICommand(HWND hWndhstmt, HWND hWndhdbc, int nIndex)
  1342. {
  1343.     char                szBuffer[MAXBUFLEN+1];    // display buffer
  1344.     HWND                hWndChild;                // MDI child window
  1345.     IDBCreateCommand*     pIDBCreate1;            // IDBCreateCommand Object #1
  1346.     IDBCreateCommand*     pIDBCreate2;            // IDBCreateCommand Object #2
  1347.     ICommand*            pICommand1;                // ICommand Object #1
  1348.     ICommand*            pICommand2;                // ICommand Object #2
  1349.  
  1350.     // Scan the ICommand and PROVIDER values from the current selections in
  1351.     // respective listboxes of disconnect dialog box.
  1352.     SendMessage(hWndhstmt, LB_GETTEXT, nIndex, (LPARAM)(LPSTR)szBuffer);
  1353.     sscanf(szBuffer, QUERY_STRING, &pICommand1);
  1354.     SendMessage(hWndhdbc, LB_GETTEXT, (UINT)SendMessage(hWndhdbc, LB_GETCURSEL,    0, 0), (LPARAM)(LPSTR)szBuffer);
  1355.     sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate1);
  1356.         
  1357.     // Go through the list of MDI child windows and find matching window
  1358.     // that has same values for PROVIDER and ICommand. Destroy the matching window.
  1359.     // That will call CloseICommandWindow and free up associated ICommand(s).
  1360.     for(hWndChild=GetWindow(hWndMDIClient, GW_CHILD); hWndChild; hWndChild=GetWindow(hWndChild, GW_HWNDNEXT))
  1361.     {
  1362.         // Ignore non MDI child windows
  1363.         GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  1364.         if( strcmp(szBuffer, OLEDBMDICLASS) )
  1365.             continue;
  1366.  
  1367.         GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  1368.         sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate2, &pICommand2);
  1369.         if (pIDBCreate1 == pIDBCreate2 && pICommand1 == pICommand2)
  1370.             break;
  1371.     }
  1372.     SendMessage(hWndMDIClient, WM_MDIDESTROY, (WPARAM)hWndChild, 0);
  1373. }
  1374.  
  1375. //**********************************************************************
  1376. // 
  1377. // CloseICommandWindow
  1378. // 
  1379. // Purpose:
  1380. // 
  1381. //     Close a ICommand window. 
  1382. //     Call ICommand->Release() to free associated ICommand(s).
  1383. //
  1384. // Parameters:
  1385. //
  1386. //     HWND             hWnd               - handle to the window
  1387. // 
  1388. // Return Value:
  1389. // 
  1390. // Function Calls:
  1391. //     Function                    Location
  1392. // 
  1393. //     ICommand::Release           provider's Command object
  1394. //     
  1395. // Comments:      
  1396. // 
  1397. // 
  1398. //**********************************************************************
  1399. void FAR PASCAL CloseICommandWindow(HWND hWnd)
  1400. {
  1401.     char        szBuffer[MAXBUFLEN+1];    // String buffer
  1402.     char        szSelect[MAXBUFLEN+1];    // Current Selected ICommand(s)
  1403.     ICommand*    pICommand;                // ICommand Object
  1404.  
  1405.     // Scan the ICommand value from the window title
  1406.     GetWindowText(hWnd, szBuffer, MAXBUFLEN);
  1407.     sscanf(szBuffer, SCANCOMMAND_TITLEFORMAT, &pICommand);
  1408.  
  1409.     // Release the Command Object & return
  1410.     if( pICommand )
  1411.         pICommand->Release();
  1412.  
  1413.     // Find the matching ICommand in the ICommand(s) combobox and remove it
  1414.     // from the list. Closure of a MDI child window will cause MDIClient
  1415.     // to automatically activate a different child window if available.
  1416.     // That will automatically refresh the ICommand and PROVIDER displays. 
  1417.     // See DisplayNewCrsrAndICommand function.
  1418.     wsprintf( szBuffer, QUERY_STRING, pICommand );
  1419.     
  1420.     SendMessage( hWndStmtList, CB_GETLBTEXT, 
  1421.                 (WPARAM)SendMessage(hWndStmtList, CB_GETCURSEL, 0, 0),
  1422.                 (LPARAM)(LPSTR)szSelect );
  1423.     
  1424.     SendMessage( hWndStmtList, CB_DELETESTRING, 
  1425.                 (WPARAM)SendMessage(hWndStmtList, CB_FINDSTRING, 0,
  1426.                 (LPARAM)(LPSTR)szBuffer), 0 );
  1427.     
  1428.     SendMessage( hWndStmtList, CB_SELECTSTRING,
  1429.                 (WPARAM)-1, 
  1430.                 (LPARAM)(LPSTR)szSelect );
  1431.     
  1432.     // Decrement the child window counter.
  1433.     nChildCount--;
  1434. }
  1435.  
  1436. //**********************************************************************
  1437. // 
  1438. // ExecuteQuery
  1439. // 
  1440. // Purpose:
  1441. // 
  1442. //     Execute the user typed SQL Statements in the currently 
  1443. //     active MDI child window. If successful, then prepare
  1444. //     the list of results and display it in the child listbox.
  1445. //     Display errors in the OLE DB function(s) failed.
  1446. //
  1447. // Parameters:
  1448. //
  1449. // Return Value:
  1450. // 
  1451. // Function Calls:
  1452. //     Function                    Location
  1453. // 
  1454. //     ExecuteCommand              query.cpp
  1455. //     GetDataFromRowset           query.cpp
  1456. // 
  1457. //     
  1458. // Comments:      
  1459. // 
  1460. // 
  1461. //**********************************************************************
  1462. void FAR PASCAL ExecuteQuery()
  1463. {
  1464.     CHAR                szBuffer[MAXBUFLEN+1];        // String Buffer
  1465.     WCHAR                wszBuffer[MAXBUFLEN+1];        // String Buffer (WCHAR)
  1466.     signed short int    swColLength = MAXDATALEN;    // Column Data Length
  1467.     HCURSOR                hOldCursor;                    // Default Cursor Handle
  1468.     IUnknown*            pIUnknown     = NULL;            // Session Object
  1469.     ICommand*            pICommand     = NULL;            // ICommand Object
  1470.     IOpenRowset*        pIOpenRowset= NULL;            // IOpenRowset Object
  1471.     IRowset*            pIRowset     = NULL;            // IRowset Object
  1472.     HRESULT                hr;                            // HRESULT
  1473.  
  1474.     // Check if there is an active window available
  1475.     if (!hWndActiveChild)
  1476.     {
  1477.         MessageBox(hWndFrame, ((SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0) <=0) ?
  1478.             MAKECONNECT : OPENWINDOW ), NOCOMMANDERROR, MB_OK | MB_ICONHAND);
  1479.         return;
  1480.     }
  1481.  
  1482.     // Change cursor shape to hour glass
  1483.     hOldCursor = SetCursor(LoadCursor((HINSTANCE)NULL, IDC_WAIT));
  1484.             
  1485.     // Scan PROVIDER, session and ICommand values
  1486.     GetWindowText(hWndActiveChild, (char*)szBuffer, MAXBUFLEN);
  1487.     sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIUnknown, &pICommand);
  1488.  
  1489.     // Get the user typed SQL
  1490.     GetWindowText(GetDlgItem((HWND)GetWindowLong(hWndActiveChild, GWLAPP_HDLG), IDTEXT_SQL), szBuffer, MAXBUFLEN);
  1491.  
  1492.     // Convert ANSI String to WCHAR    String
  1493.     MultiByteToWideChar(CP_ACP, 0, szBuffer, -1, wszBuffer, MAXBUFLEN+1);
  1494.  
  1495.     // Execute the Command Object
  1496.     hr = ExecuteCommand( pIUnknown, pICommand, wszBuffer, &pIRowset ); 
  1497.  
  1498.     if (FAILED(hr))
  1499.         return;
  1500.  
  1501.     // Empty IRowset
  1502.     if( hr == ResultFromScode(S_FALSE) )
  1503.     { 
  1504.         DumpErrorHResult( ResultFromScode(S_OK), (LPSTR)"ExecuteCommand returned No Rowset!!" );
  1505.         return;
  1506.     }
  1507.  
  1508.     // Get Data from the IRowset Object
  1509.     GetDataFromRowset( pIRowset );
  1510. }
  1511.  
  1512.  
  1513. //**********************************************************************
  1514. // 
  1515. // CloseIDBCreateCommand
  1516. // 
  1517. // Purpose:
  1518. // 
  1519. //     Go through all open PROVIDER's (IDBCreateCommand(s) and ICommand(s)) 
  1520. //     and close them one by one.
  1521. //
  1522. // Parameters:
  1523. //
  1524. // Return Value:
  1525. // 
  1526. // Function Calls:
  1527. //     Function                    Location
  1528. // 
  1529. //     IDBCreateCommand::Release   provider's Command object
  1530. //     
  1531. // Comments:      
  1532. // 
  1533. // 
  1534. //**********************************************************************
  1535. BOOL FAR PASCAL CloseIDBCreateCommand()
  1536. {
  1537.     ULONG                 nIndex;                    // Index
  1538.     ULONG                nCount;                    // # of PROVIDER(s)
  1539.     char                szBuffer[MAXBUFLEN+1];    // String Buffer
  1540.     HWND                hWndChild;                // MDI Child Window
  1541.     IDBCreateCommand*     pIDBCreate1;            // IDBCreateCommand Object #1
  1542.     IDBCreateCommand*     pIDBCreate2;            // IDBCreateCommand Object #2
  1543.  
  1544.     // Get count of connected PROVIDER(s) from the PROVIDER(s) combobox on the toolbar
  1545.     if (!(nCount = (int)SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0)))
  1546.         return (TRUE);
  1547.  
  1548.     // Go through all available MDI child windows and for each PROVIDER,
  1549.     // find the matching MDI child window and ask it for closure, thereby
  1550.     // freeing the associated ICommand (see CloseICommandWindow). Once all
  1551.     // associated ICommand(s) are freed, free the PROVIDER
  1552.     for (nIndex = 0; nIndex < nCount; nIndex++)
  1553.     {       
  1554.         // Scan current indexed PROVIDER from PROVIDER(s) combobox
  1555.         SendMessage(hWndCrsrList, CB_GETLBTEXT, (WPARAM)nIndex, (LPARAM)(LPSTR)szBuffer);
  1556.         sscanf(szBuffer, SCANSESSION_FORMAT, &pIDBCreate1);
  1557.         
  1558.         // Search through the list of MDI Child Windows
  1559.         for(hWndChild = GetWindow(hWndMDIClient, GW_CHILD); hWndChild; )
  1560.         {
  1561.             // Store the next child, before destroying the current
  1562.             HWND hWndTemp = GetWindow(hWndChild, GW_HWNDNEXT);
  1563.         
  1564.             // Ignore non MDI child windows
  1565.             GetClassName(hWndChild, szBuffer, MAXBUFLEN);
  1566.             if (!strcmp(szBuffer, OLEDBMDICLASS))
  1567.             {
  1568.                 GetWindowText(hWndChild, szBuffer, MAXBUFLEN);
  1569.                 sscanf(szBuffer, SCANSESSION_TITLEFORMAT, &pIDBCreate2);
  1570.                 if (pIDBCreate1 == pIDBCreate2)
  1571.                 {
  1572.                     // Destroy the window and restart search
  1573.                     SendMessage(hWndMDIClient, WM_MDIDESTROY, (WPARAM)hWndChild, 0);
  1574.                     hWndTemp = GetWindow(hWndMDIClient, GW_CHILD);
  1575.                 }
  1576.             }
  1577.             hWndChild = hWndTemp;
  1578.         }
  1579.  
  1580.         // Call IDBCreateCommand->Release() 
  1581.         // to free the current IDBCreateCommand resource
  1582.         if( pIDBCreate1 )
  1583.             pIDBCreate1->Release();
  1584.     }
  1585.     
  1586.     // Reset the PROVIDER(s) combobox display and display all connections
  1587.     // closed message. Return success to let application exit.
  1588.     SendMessage(hWndCrsrList, CB_RESETCONTENT, 0, 0);
  1589.     MessageBox(hWndFrame, CLOSEALLSESSION, LOGOUTINFO,    MB_OK | MB_ICONINFORMATION);
  1590.     return (TRUE);
  1591. }
  1592.  
  1593. /*
  1594.     FUNCTION: FreeEnvironment()
  1595.     COMMENTS: Free the OLE environment.
  1596. */
  1597. HRESULT FreeEnvironment()
  1598. {
  1599.     IErrorInfo    *pIErrorInfo;    //IErrorInfo
  1600.  
  1601.     // Release the task memory allocator
  1602.     if( g_pIMalloc )
  1603.         g_pIMalloc->Release();
  1604.  
  1605.     // Release any remaining error objects.  This is idempotent.
  1606.     // Otherwise the provider might have an outstanding global-object count.
  1607.     GetErrorInfo( 0, &pIErrorInfo );
  1608.     if (pIErrorInfo)
  1609.         pIErrorInfo->Release();
  1610.  
  1611.     // Free the error queues
  1612.     SetErrorInfo(0,NULL);
  1613.  
  1614.     // Uninitialize OLE
  1615.     CoUninitialize();
  1616.     return S_OK;
  1617. }
  1618.  
  1619.  
  1620. //**********************************************************************
  1621. // 
  1622. // ExecuteCommand
  1623. // 
  1624. // Purpose:
  1625. // 
  1626. //    Executes the query command that was previously set on the Command object,
  1627. //    and returns a first interface pointer on the resulting Rowset object.
  1628. // 
  1629. // Parameters:
  1630. //       IOpenRowset*    pIOpenRowset    - interface pointer to data provider's
  1631. //                                      IOpenRowset
  1632. //       ICommand*        pICommand       - interface pointer on data provider's
  1633. //                                      Command object
  1634. //       LPWSTR        wszBuffer        - SQL-style query string to be sent
  1635. //                                      to the Command object or table/file name to
  1636. //                                      be sent to IOpenRowset
  1637. //       IRowset**        ppIRowset_out   - out pointer through which to return 
  1638. //                                      interface pointer on provider's
  1639. //                                      Rowset object
  1640. // 
  1641. // Return Value:
  1642. //     S_OK        - Success
  1643. //     E_*         - Failure
  1644. // 
  1645. // Function Calls:
  1646. //     Function                    Location
  1647. //     
  1648. //     ICommand::Execute           provider's Command object
  1649. //     IMalloc::Free               OLE task memory allocator
  1650. //     
  1651. // 
  1652. //     assert                      c runtime
  1653. // 
  1654. // 
  1655. //     
  1656. // Comments:      
  1657. // 
  1658. //     The interface pointer returned through ppIRowset_out has been AddRef'ed, 
  1659. //     it must be Release'd later by the caller.
  1660. //
  1661. //**********************************************************************
  1662. HRESULT ExecuteCommand(
  1663.     IUnknown*    pIUnknown,        // Session object
  1664.     ICommand*    pICommand,        // Command object
  1665.     LPWSTR         wszBuffer,        // SQL String (WCHAR) or Table Name
  1666.     IRowset**    ppIRowset_out
  1667.     )
  1668. {
  1669.     ICommandText*        pICommandText = NULL;    // ICommandText Object
  1670.     IOpenRowset*        pIOpenRowset = NULL;
  1671.     DBID                TableID;                // Table ID
  1672.     HRESULT                hr = S_OK;                // HRESULT
  1673.  
  1674.     // Asserts
  1675.     assert(ppIRowset_out != NULL);
  1676.     assert(wszBuffer != NULL);
  1677.  
  1678.     memset(&TableID, 0, sizeof(DBID));
  1679.  
  1680.     // If no command object use IOpenRowset
  1681.     if (NULL == pICommand)
  1682.     {
  1683.         // if no Command object support, attempt to get the IOpenRowset interface
  1684.         if( FAILED(hr = pIUnknown->QueryInterface(IID_IOpenRowset, (void**)&pIOpenRowset)) )
  1685.         {
  1686.             GetDetailedErrorInfo(hr, pIUnknown, IID_IUnknown, "QI for IOpenRowset FAILED!!");
  1687.             goto error;
  1688.         }
  1689.         // Pass in table/file name
  1690.         TableID.eKind = DBKIND_NAME;
  1691.  
  1692.         TableID.uName.pwszName = wszBuffer;
  1693.  
  1694.         // From IOpenRowset, get a rowset object
  1695.         if( FAILED(hr = pIOpenRowset->OpenRowset(
  1696.                                 NULL,                            // pUnkOuter
  1697.                                 &TableID,                        // pTableID
  1698.                                 NULL,                            // pIndexID
  1699.                                 IID_IRowset,                    // refiid
  1700.                                 0,                                // cProperties
  1701.                                 NULL,                            // rgProperties
  1702.                                  (IUnknown**)ppIRowset_out)) )          // IRowset pointer
  1703.         {
  1704.              GetDetailedErrorInfo(hr, pIOpenRowset, IID_IOpenRowset, "IOpenRowset->OpenRowset FAILED!!");
  1705.             goto error;
  1706.         }
  1707.     }
  1708.     else
  1709.     {
  1710.         // QueryInterface for ICommandText::SetCommandText
  1711.         if( SUCCEEDED(hr = pICommand->QueryInterface(IID_ICommandText,(LPVOID*)&pICommandText)) )
  1712.         {
  1713.             // Tell the command object to copy this command text
  1714.             // The command object will then use this query when we call ICommand::Execute
  1715.             if( FAILED(hr = pICommandText->SetCommandText(DBGUID_DBSQL, wszBuffer)) )
  1716.             {
  1717.                 GetDetailedErrorInfo(hr, pICommandText, IID_ICommandText, "ICommandText->SetCommandText FAILED!!");
  1718.                 goto error;
  1719.             }
  1720.         }
  1721.  
  1722.         // From the command object, get a rowset object by executing command
  1723.         if( FAILED(hr = pICommand->Execute(
  1724.                             NULL,                            // pUnkOuter
  1725.                             IID_IRowset,                    // refiid
  1726.                             NULL,                            // disp parms
  1727.                             NULL,                            // rows affected
  1728.                              (IUnknown**)ppIRowset_out)) )      // IRowset pointer
  1729.         {
  1730.             GetDetailedErrorInfo(hr, pICommand, IID_ICommand, "ICommand->Execute FAILED!!");
  1731.             goto error;
  1732.         }
  1733.     }
  1734.  
  1735.     // NO Rowset Returning Statement
  1736.     if( !*ppIRowset_out )
  1737.         hr = ResultFromScode(S_FALSE);
  1738. error:
  1739.     if( pICommandText )
  1740.         pICommandText->Release();
  1741.     if( pIOpenRowset )
  1742.         pIOpenRowset->Release();
  1743.  
  1744.     if( FAILED(hr) )
  1745.         *ppIRowset_out = NULL;
  1746.  
  1747.     return hr;    
  1748. }
  1749.  
  1750. //**********************************************************************
  1751. // 
  1752. // GetDataFromRowset
  1753. // 
  1754. // Purpose:
  1755. // 
  1756. //     Pulls the data from a Rowset object.
  1757. //     
  1758. // Parameters:
  1759. // 
  1760. //     IRowset*    pIRowset    -  interface pointer on data provider's
  1761. //                             Rowset object
  1762. // 
  1763. // Return Value:
  1764. // 
  1765. //     S_OK        - Success
  1766. //     E_*         - Failure
  1767. // 
  1768. // Function Calls:
  1769. //     Function                    Location
  1770. // 
  1771. //       IRowset::QueryInterface       Clients Rowset pointer
  1772. //     SetupBindings               query.cpp
  1773. //     CreateAccessor              query.cpp
  1774. //     GetData                     query.cpp
  1775. //     CleanupRowset               query.cpp
  1776. // 
  1777. //     IMalloc::Free               OLE task memory allocator
  1778. // 
  1779. //     assert                      c runtime
  1780. // 
  1781. // Comments:      
  1782. // 
  1783. //     At a high level, a consumer pulls the data from a Rowset object by:
  1784. //     
  1785. //     1. getting metadata for the Rowset's columns
  1786. //     2. using that metadata, along with the consumer's own knowledge of
  1787. //        how it wants to recieve the data, to create bindings. Bindings
  1788. //        represent how the actual data in the Rowset's columns is
  1789. //        actually transferred to the consumer's buffer.
  1790. //     3. pass the bindings to the Rowset, and get in return an accessor
  1791. //        handle that represents that particular set of bindings   
  1792. //     4. get the actual data
  1793. //     5. clean up the rowset (at a minumum, release the accessor) 
  1794. //     
  1795. //     GetDataFromRowset performs these steps by calling GetColumnsInfo,
  1796. //     SetupBindings, CreateAccessor, GetData, and CleanupRowset
  1797. //       
  1798. //**********************************************************************
  1799. HRESULT GetDataFromRowset(
  1800.     IRowset*    pIRowset
  1801.     )
  1802. {
  1803.     char                szBuffer[MAXBUFLEN+1];        // String Buffer
  1804.     HWND                hList;                        // Result Listbox Handle
  1805.     DWORD                 dwText;                        // Tab Stop for Listbox
  1806.     unsigned short int    nCount;                        // Index
  1807.     signed short int    swColLength = MAXDATALEN;    // Column Data Length
  1808.     int                    cch;                        // Count of characters
  1809.     HRESULT                hr = S_OK;                            // HRESULTS
  1810.     ULONG                cCol;                        // # of Columns in Rowset
  1811.     DBCOLUMNINFO*        pColumnInfo;                // Array of DBCOLUMNINFO
  1812.     WCHAR*                pStringsBuffer;                // Storage for strings
  1813.  
  1814.     // BINDINGS
  1815.     ULONG                 cbMaxRowSize;        // buffer size for 1 row's data
  1816.     ULONG                 cBind;
  1817.     DBBINDING            rgBind[MAX_COL];
  1818.     HCURSOR                hOldCursor = NULL;
  1819.  
  1820.     // ACCESSORS
  1821.     HACCESSOR            hAccessor        = NULL;
  1822.  
  1823.     // Asserts
  1824.     assert(pIRowset   != NULL);
  1825.     assert(g_pIMalloc != NULL);
  1826.     
  1827.     // Change cursor shape to hour glass
  1828.     hOldCursor = SetCursor(LoadCursor((HINSTANCE)NULL, IDC_WAIT));
  1829.     
  1830.     // Get the Columns Info
  1831.     GetColumnsInfo( pIRowset, &cCol, &pColumnInfo, &pStringsBuffer);
  1832.  
  1833.     // Call GetColumnsInfo to calculate the number of columns in
  1834.     // the result set, if more than the MAX_COL (the array boundary)
  1835.     // limit the number to MAX_COL and display truncation warning.
  1836.     // if it is 0, the statement probably was a non-SELECT simply return
  1837.     if (cCol >= MAX_COL)
  1838.     {
  1839.         cCol = MAX_COL;
  1840.         wsprintf(szDispBuffer, COLTRUNC_WARNG, MAX_COL);
  1841.         MessageBox(hWndFrame, szDispBuffer, TRUNCERR, MB_OK | MB_ICONINFORMATION);
  1842.     }
  1843.     else if (cCol == 0)
  1844.     {
  1845.         goto error;
  1846.     }
  1847.  
  1848.     // Reset the display in the list box. Set tabstops to display
  1849.     // multiple columns in the list box separated by tabs.
  1850.     hList = GetDlgItem((HWND)GetWindowLong(hWndActiveChild, GWLAPP_HDLG), IDLIST_RSLT);
  1851.  
  1852.     SendMessage(hList, LB_RESETCONTENT, 0, 0);
  1853.     SendMessage(hList, WM_SETREDRAW, FALSE, 0);
  1854.     dwText = LISTTABSTOP;
  1855.     SendMessage(hList, LB_SETTABSTOPS, (WPARAM)1, (LPARAM)(LPINT)&dwText);
  1856.  
  1857.     // Display a description of each column in the result set. 
  1858.     // Store the column name in the display buffer and make it
  1859.     // the first entry in the results list box of the MDI child window.
  1860.     for(nCount=0, szDispBuffer[0]='\0'; nCount < cCol; nCount++)
  1861.     {
  1862.         if (pColumnInfo[nCount].pwszName)
  1863.         {
  1864.             cch = WideCharToMultiByte(CP_ACP, 0, pColumnInfo[nCount].pwszName, -1, szBuffer, MAXBUFLEN+1, NULL, NULL);
  1865.  
  1866.             // Truncate if needed.
  1867.             // We should use GetTextExtents to determine width, but that's too complicated for now.
  1868.             szBuffer[MAXCOLNAMELEN] = '\0';
  1869.  
  1870.             // Might be empty string for column name.
  1871.             if (cch)
  1872.                 strcat(szDispBuffer, szBuffer);
  1873.             else
  1874.                 strcat(szDispBuffer, "<EMPTY STRING>");
  1875.         }
  1876.         else
  1877.         {
  1878.             // Missing the column name; it is unknown.
  1879.             strcat(szDispBuffer, "<NULL STRING>");
  1880.         }
  1881.  
  1882.         dwText = strlen(szDispBuffer);
  1883.         szDispBuffer[dwText++] = '\t';
  1884.         szDispBuffer[dwText] = '\0';
  1885.     }
  1886.  
  1887.     // NULL Terminate the Display Buffer
  1888.     if (*szDispBuffer)
  1889.         szDispBuffer[strlen(szDispBuffer)-1]='\0';
  1890.     
  1891.     // ADD the Column Info to the Screen
  1892.     SendMessage(hList, LB_ADDSTRING, 0, (LPARAM)(LPSTR)szDispBuffer);
  1893.  
  1894.     // SetUp Bindings
  1895.     if( FAILED(hr = SetupBindings( cCol, pColumnInfo, rgBind, &cBind, &cbMaxRowSize)) )
  1896.         goto error;
  1897.     
  1898.     // Create the Accessor
  1899.     if( FAILED(hr = CreateAccessor( pIRowset, rgBind, cBind, &hAccessor)) )
  1900.         goto error;
  1901.  
  1902.     // GetData
  1903.     if( FAILED(hr = GetData( pIRowset, cbMaxRowSize, hAccessor, rgBind, cBind, pColumnInfo, 
  1904.         cCol, hList, dwText, LB_ADDSTRING)) )
  1905.         goto error;
  1906.  
  1907. error:    
  1908.     // restore the cursor to default value
  1909.     SetCursor(hOldCursor);
  1910.   
  1911.     // Release the IColumnsInfo Object
  1912.     if( pColumnInfo )
  1913.         g_pIMalloc->Free( pColumnInfo );
  1914.     if( pStringsBuffer )
  1915.         g_pIMalloc->Free( pStringsBuffer );            
  1916.         
  1917.     // Clean-up the Rowset
  1918.     CleanupRowset( pIRowset, hAccessor );
  1919.  
  1920.     return hr;    
  1921. }
  1922.  
  1923.  
  1924. //**********************************************************************
  1925. // 
  1926. // GetColumnsInfo
  1927. // 
  1928. // Purpose:
  1929. // 
  1930. //     Get the Columns metadata back for the provider to setup the bundings. 
  1931. //     
  1932. // Parameters:
  1933. //
  1934. //    IRowset*        pIRowset            - IRowset pointer to QI off of
  1935. //     ULONG             cCol                - number of columns in metadata
  1936. //     DBCOLUMNINFO*    pColumnInfo         - pointer to column metadata
  1937. //     WCHAR*            pStringsBuffer      - pointer through which to return
  1938. //                                        an array of string data, one
  1939. //                                        structure per column bound
  1940. // 
  1941. // Return Value:
  1942. //     S_OK         - Success
  1943. //     E_*          - Failure
  1944. // 
  1945. // Function Calls:
  1946. //     Function                    Location
  1947. // 
  1948. //     assert                      c runtime
  1949. //     IRowset::QueryInterface     provider's Rowset object
  1950. //     IColumnsInfo::GetColumnInfo provider's ColumnInfo object
  1951. //     IColumnsInfo::Release       provider's ColumnInfo object
  1952. // 
  1953. //     
  1954. // Comments:      
  1955. // 
  1956. // 
  1957. //**********************************************************************
  1958. HRESULT GetColumnsInfo
  1959.     (
  1960.     IRowset*        pIRowset,
  1961.     ULONG*             pcCol,
  1962.     DBCOLUMNINFO**    ppColumnInfo,
  1963.     WCHAR**            ppStringsBuffer
  1964.     )
  1965. {
  1966.  
  1967.     HRESULT                hr=NOERROR;                    // HRESULTS
  1968.     IColumnsInfo*         pIColumnsInfo = NULL;        // IColumnsInfo Object
  1969.  
  1970.     // QI for IColumnsInfo Object
  1971.     if( FAILED(hr = pIRowset->QueryInterface( IID_IColumnsInfo, (void **) &pIColumnsInfo)) )
  1972.     {
  1973.         GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "QI for IColumnsInfo FAILED!!");
  1974.         goto error;
  1975.     }
  1976.     
  1977.     // Get column information from the command object via IColumnsInfo::GetColumnsInfo 
  1978.     if( FAILED(hr = pIColumnsInfo->GetColumnInfo( pcCol, ppColumnInfo, ppStringsBuffer)) )
  1979.     {
  1980.         GetDetailedErrorInfo(hr, pIColumnsInfo, IID_IColumnsInfo, "IColumnsInfo->GetColumnsInfo FAILED!!");
  1981.         goto error;
  1982.     }
  1983.  
  1984. error:
  1985.     // Release the IColumnsInfo Object
  1986.     if( pIColumnsInfo )
  1987.         pIColumnsInfo->Release();
  1988.     return hr;
  1989.  
  1990. }
  1991.  
  1992. //**********************************************************************
  1993. // 
  1994. // SetupBindings
  1995. // 
  1996. // Purpose:
  1997. // 
  1998. //     Creates bindings that map the data in the rowset's columns to 
  1999. //     slots in the consumer's data buffer.
  2000. //     
  2001. // Parameters:
  2002. //
  2003. //     ULONG             cCol                - number of columns in rowset to bind
  2004. //     DBCOLUMNINFO*    pColumnInfo         - pointer to column metadata
  2005. //     DBBINDING*        rgBind_out          - out pointer through which to return
  2006. //                                        an array of binding structures, one
  2007. //                                        structure per column bound
  2008. //     ULONG*            pcBind_out          - out pointer through which to return   
  2009. //                                        the number of columns bound (number
  2010. //                                        of valid elements in rgBind_out)              
  2011. //     ULONG*            pcMaxRowSize_out    - out pointer through which to return
  2012. //                                        the buffer size necessary to hold
  2013. //                                        the largest row data
  2014. // 
  2015. // Return Value:
  2016. //     S_OK         - Success
  2017. //     E_*          - Failure
  2018. // 
  2019. // Function Calls:
  2020. //     Function                    Location
  2021. // 
  2022. //     assert                      c runtime
  2023. // 
  2024. //     
  2025. // Comments:      
  2026. // 
  2027. // 
  2028. //**********************************************************************
  2029. HRESULT SetupBindings
  2030.     (
  2031.     ULONG             cCol,
  2032.     DBCOLUMNINFO*    pColumnInfo,
  2033.     DBBINDING*        rgBind_out,
  2034.     ULONG*            pcBind_out,
  2035.     ULONG*            pcMaxRowSize_out
  2036.     )
  2037. {
  2038.     #define DEFAULT_CBMAXLENGTH 80    // cbMaxLength for binding
  2039.     ULONG dwOffset;                // Length of a Row
  2040.     ULONG iCol;                    // Column Count
  2041.     ULONG iBind;                // Binding Index
  2042.     
  2043.     // Asserts
  2044.     assert(pColumnInfo        != NULL);
  2045.     assert(rgBind_out         != NULL);
  2046.     assert(pcBind_out         != NULL);
  2047.     assert(pcMaxRowSize_out != NULL);
  2048.  
  2049.        // Create bindings.
  2050.     // Bind everything as a string just to keep things simple.
  2051.     dwOffset = 0;
  2052.     iBind=0;
  2053.     for (iCol=0; iCol < cCol; iCol++)
  2054.     {
  2055.         // Binding Structure
  2056.         rgBind_out[iBind].dwPart    = DBPART_VALUE | DBPART_LENGTH |
  2057.                                       DBPART_STATUS;
  2058.         rgBind_out[iBind].eParamIO  = DBPARAMIO_NOTPARAM;
  2059.         rgBind_out[iBind].iOrdinal    = pColumnInfo[iCol].iOrdinal;
  2060.         rgBind_out[iBind].wType     = DBTYPE_WSTR;
  2061.         rgBind_out[iBind].pTypeInfo = NULL;
  2062.         rgBind_out[iBind].obValue   = dwOffset + offsetof(COLUMNDATA,bData);
  2063.         rgBind_out[iBind].obLength  = dwOffset + offsetof(COLUMNDATA,dwLength);
  2064.         rgBind_out[iBind].obStatus  = dwOffset + offsetof(COLUMNDATA,wStatus);
  2065.  
  2066.         // If columns information is a STR, double buffer and 
  2067.         // add space for terminator
  2068.         if( ((pColumnInfo[iCol].wType == DBTYPE_STR) ||
  2069.              (pColumnInfo[iCol].wType == DBTYPE_WSTR)) && 
  2070.             (pColumnInfo[iCol].ulColumnSize != 0xffffffff) )
  2071.             rgBind_out[iBind].cbMaxLen = (pColumnInfo[iCol].ulColumnSize + sizeof(CHAR)) * 2;
  2072.         else
  2073.             rgBind_out[iBind].cbMaxLen = DEFAULT_CBMAXLENGTH;
  2074.         rgBind_out[iBind].pObject    = NULL;
  2075.         rgBind_out[iBind].pBindExt    = NULL;
  2076.         rgBind_out[iBind].dwFlags    = 0;
  2077.         rgBind_out[iBind].dwMemOwner = DBMEMOWNER_CLIENTOWNED;
  2078.         rgBind_out[iBind].bPrecision = 0;
  2079.         rgBind_out[iBind].bScale    = 0;
  2080.         
  2081.         // LONG DATA hack 
  2082.         if(rgBind_out[iBind].cbMaxLen > 1000)
  2083.             rgBind_out[iBind].cbMaxLen = 1000;
  2084.  
  2085.         dwOffset += rgBind_out[iBind].cbMaxLen + offsetof( COLUMNDATA, bData );
  2086.         dwOffset = ROUND_UP( dwOffset, COLUMN_ALIGNVAL );
  2087.         iBind++;
  2088.     }  
  2089.  
  2090.     // Return Values    
  2091.     *pcBind_out       = iBind;
  2092.     *pcMaxRowSize_out = dwOffset;
  2093.  
  2094.     return S_OK;
  2095. }
  2096.  
  2097.  
  2098.  
  2099. //**********************************************************************
  2100. // 
  2101. // CreateAccessor
  2102. // 
  2103. // Purpose:
  2104. //
  2105. //     Passes a set of bindings to the data provider and recieves in return
  2106. //     an accessor handle that represents those bindings. 
  2107. //      
  2108. // Parameters:
  2109. //     IRowset*    pIRowset        - interface pointer on data provider's Rowset
  2110. //                                object
  2111. //     DBBINDING*    rgBind          - array of binding structures
  2112. //     ULONG        cBind           - number of binding structures in rgBind
  2113. //     HACCESSOR*    phAccessor_out  - out pointer through which to return an 
  2114. //                                accessor handle that represents all the bindings
  2115. //                                in rgBind
  2116. // 
  2117. // Return Value:
  2118. //     S_OK        - Success
  2119. //     E_*         - Failure
  2120. // 
  2121. // Function Calls:
  2122. //     Function                    Location
  2123. // 
  2124. //     IRowset::QueryInterface     provider's Rowset object
  2125. //     IAccessor::CreateAccessor   provider's Rowset object
  2126. //     IAccessor::Release          provider's Rowset object
  2127. // 
  2128. //     assert                      c runtime
  2129. //     
  2130. // Comments:      
  2131. // 
  2132. // 
  2133. //**********************************************************************
  2134. HRESULT CreateAccessor
  2135.     (
  2136.     IRowset*    pIRowset,
  2137.     DBBINDING*    rgBind,
  2138.     ULONG        cBind,
  2139.     HACCESSOR*    phAccessor_out 
  2140.     )
  2141. {
  2142.     IAccessor*    pIAccessor = NULL;
  2143.     HRESULT     hr;
  2144.  
  2145.     // Asserts
  2146.     assert(pIRowset       != NULL);
  2147.     assert(rgBind           != NULL);
  2148.     assert(phAccessor_out != NULL);
  2149.  
  2150.       // Get an accessor for our bindings from the rowset, via IAccessor 
  2151.     if( FAILED(hr = pIRowset->QueryInterface( IID_IAccessor, (void**)&pIAccessor)) )
  2152.     {
  2153.         GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "QI for IAccessor FAILED!!");
  2154.         goto error;
  2155.     }
  2156.  
  2157.     if( FAILED(hr = pIAccessor->CreateAccessor(
  2158.                         DBACCESSOR_ROWDATA, 
  2159.                         cBind, 
  2160.                         rgBind, 
  2161.                         0, 
  2162.                         phAccessor_out,
  2163.                         NULL)) )
  2164.     {
  2165.         GetDetailedErrorInfo(hr, pIAccessor, IID_IAccessor, "IAccessor->CreateAccessor FAILED!!");
  2166.         goto error;
  2167.     }
  2168.  
  2169.     hr = S_OK;    
  2170.  
  2171. error:
  2172.     if (pIAccessor)
  2173.         pIAccessor->Release();
  2174.  
  2175.     if( FAILED(hr) )
  2176.         *phAccessor_out = NULL;
  2177.                 
  2178.     return hr;    
  2179. }
  2180.  
  2181.  
  2182. //**********************************************************************
  2183. // 
  2184. // GetData
  2185. // 
  2186. // Purpose:
  2187. // 
  2188. //     Reads the data from a rowset.
  2189. // 
  2190. // Parameters:
  2191. //
  2192. //        IRowset*     pIRowset           - interface pointer on data provider's
  2193. //                                    Rowset object
  2194. //        ULONG        cMaxRowSize        - size of buffer needed to hold the data
  2195. //                                    for the largest row
  2196. //     HACCESSOR hAccessor          - accessor handle representing the set
  2197. //                                    of desired bindings
  2198. //     DBBINDING*        rgBind          - needed only for pretty printing    
  2199. //     ULONG            cBind          - for pretty printing  
  2200. //     DBCOLUMNINFO*    pColumnInfo - for pretty printing  
  2201. //     ULONG            cCol        - for pretty printing  
  2202. // 
  2203. // 
  2204. // Return Value:
  2205. //     S_OK        - Success
  2206. //     E_*         - Failure
  2207. // 
  2208. // Function Calls:
  2209. //     Function                    Location
  2210. // 
  2211. //     IRowset::GetNextRows        provider's Rowset object
  2212. //     IRowset::GetData            provider's Rowset object
  2213. //     IRowset::ReleaseRows        provider's Rowset object
  2214. // 
  2215. // 
  2216. //     malloc, free                c runtime
  2217. //     assert                      c runtime
  2218. // 
  2219. // 
  2220. //     
  2221. // Comments:      
  2222. //
  2223. //     GetData reads all the rows in the rowset, sequentially.
  2224. //  
  2225. // 
  2226. //**********************************************************************
  2227. HRESULT GetData
  2228.     (
  2229.     IRowset*        pIRowset,
  2230.     ULONG           cMaxRowSize,
  2231.     HACCESSOR       hAccessor,
  2232.     DBBINDING*        rgBind,            
  2233.     ULONG            cBind,            
  2234.     DBCOLUMNINFO*    pColumnInfo,  
  2235.     ULONG            cCol,
  2236.     HWND            hList,
  2237.     DWORD            dwText,
  2238.     DWORD            addString
  2239.     )
  2240. {
  2241.     #define NUMROWS_CHUNK       20    // Number of Rows to Grab at a Time
  2242.  
  2243.     ULONG     cRowsObtained;            // Number of rows obtained
  2244.     ULONG    iRow;                    // Row Count
  2245.     BYTE*    pRowData = NULL;        // Memory for Data
  2246.     HROW     rghRows[NUMROWS_CHUNK];    // Row Handles
  2247.     HROW*    pRows = &rghRows[0];    // Pointer to the Row Handles
  2248.     ULONG    cMaxColWidth = 0;          // Needed for Output
  2249.     HRESULT hr;                        // HRESULT
  2250.  
  2251.     // Asserts
  2252.     assert(pIRowset     != NULL);
  2253.     assert(rgBind         != NULL);
  2254.     assert(pColumnInfo  != NULL);
  2255.  
  2256.     // Create a buffer for row data, big enough to hold the biggest row
  2257.     pRowData = (BYTE *) malloc( cMaxRowSize );
  2258.     if (!pRowData)
  2259.         goto error;
  2260.  
  2261.     // Process all the rows, NUMROWS_CHUNK rows at a time
  2262.     while (1)
  2263.     {
  2264.         if( FAILED(hr = pIRowset->GetNextRows(
  2265.             0,                            // cbChapter
  2266.             0,                            // cRowsToSkip
  2267.             NUMROWS_CHUNK,                // cRowsDesired
  2268.             &cRowsObtained,                // cRowsObtained
  2269.             &pRows)) )                    // filled in w/ row handles
  2270.         {
  2271.             GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "IRowset->GetNextRows FAILED!!");
  2272.             goto error;
  2273.         }
  2274.  
  2275.         // All done, no more rows left to get
  2276.         if ( cRowsObtained == 0 )
  2277.             break;
  2278.  
  2279.         // Loop over rows obtained, getting data for each
  2280.         for ( iRow=0; iRow < cRowsObtained; iRow++ )
  2281.         {
  2282.             if( FAILED(hr = pIRowset->GetData(
  2283.                 rghRows[iRow],
  2284.                 hAccessor,
  2285.                 pRowData)) )
  2286.             {
  2287.                 GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "IRowset->GetData FAILED!!");
  2288.                 goto error;
  2289.             }
  2290.  
  2291.             
  2292.             // Print to the Screen
  2293.             DumpRow( rgBind, cBind, cMaxColWidth, pRowData, hList, dwText, addString );
  2294.  
  2295.             // See if you are over the limit of rows
  2296.             if ((iRow + 1) == MAX_ROW)
  2297.             {
  2298.                 wsprintf(szDispBuffer, ROWTRUNC_WARNG, MAX_ROW);
  2299.                 MessageBox(hWndFrame, szDispBuffer, TRUNCERR, MB_OK | MB_ICONINFORMATION);
  2300.                 break;
  2301.             }
  2302.  
  2303.         }
  2304.  
  2305.         // Release row handles
  2306.         if( FAILED(hr = pIRowset->ReleaseRows( cRowsObtained, rghRows, NULL, NULL, NULL)) )
  2307.         {
  2308.            GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "IRowset->ReleaseRows FAILED!!");
  2309.            goto error;
  2310.         }
  2311.  
  2312.     }    // end while
  2313.  
  2314.     hr = S_OK;
  2315. error:
  2316.     // Set the horizontal scroll extent in the list box and ask for repaint.
  2317.     SendMessage(hList, LB_SETHORIZONTALEXTENT, (WPARAM)(cBind*LISTHORZSCROLL+LISTHORZEXT), 0);
  2318.     SendMessage(hList, WM_SETREDRAW, TRUE, 0);
  2319.  
  2320.     if( cRowsObtained )
  2321.         pIRowset->ReleaseRows( cRowsObtained, rghRows, NULL, NULL, NULL);
  2322.     
  2323.     if( pRowData )
  2324.         free( pRowData );
  2325.                                 
  2326.     return hr;
  2327. }
  2328.  
  2329. //**********************************************************************
  2330. // 
  2331. // GetSchemaRowset
  2332. // 
  2333. // Purpose:
  2334. // 
  2335. //     Pulls the schema info out of the provider.
  2336. //     
  2337. // Parameters:
  2338. // 
  2339. //     GUID  rguidSchema        -  SchemaRowset IID
  2340. //
  2341. //
  2342. // Return Value:
  2343. // 
  2344. // Function Calls:
  2345. //     Function                              Location
  2346. // 
  2347. //       IDBCreateCommand::QueryInterface   QI
  2348. //       IDBSchemaRowset->GetRowset          Clients Rowset pointer
  2349. //     GetDataFromRowset                     query.cpp
  2350. // 
  2351. //     IMalloc::Free                         OLE task memory allocator
  2352. // 
  2353. //     assert                                c runtime
  2354. // 
  2355. // Comments:      
  2356. // 
  2357. //       
  2358. //**********************************************************************
  2359. void FAR PASCAL GetSchemaRowset(GUID rguidSchema)
  2360. {
  2361.     char                szBuffer[MAXBUFLEN+1];        // String Buffer
  2362.     HCURSOR                hOldCursor;                    // Default Cursor Handle
  2363.     IDBCreateCommand*     pIDBCreate          = NULL;    // IDBCreateCommand Object
  2364.     IDBSchemaRowset*    pIDBSchemaRowset = NULL;    // SchemaRowset Object
  2365.     ICommand*            pICommand         = NULL;    // Command Object
  2366.     IRowset*            pIRowset         = NULL;    // Rowset Object
  2367.     HRESULT                hr;                            // HRESULT
  2368.  
  2369.     // Check if there is an active window available
  2370.     if( !hWndActiveChild )
  2371.     {
  2372.         MessageBox( hWndFrame, 
  2373.                     ((SendMessage(hWndCrsrList, CB_GETCOUNT, 0, 0) <=0) ?
  2374.                     MAKECONNECT : OPENWINDOW ), 
  2375.                     NOCOMMANDERROR, MB_OK | MB_ICONHAND);
  2376.         return;
  2377.     }
  2378.  
  2379.     // Change cursor shape to hour glass
  2380.     hOldCursor = SetCursor(LoadCursor((HINSTANCE)NULL, IDC_WAIT));
  2381.             
  2382.     // Scan hdbc, hstmt values
  2383.     GetWindowText(hWndActiveChild, (char*)szBuffer, MAXBUFLEN);
  2384.     sscanf(szBuffer, SCANSESSIONCOMMAND_FORMAT, &pIDBCreate, &pICommand);
  2385.     
  2386.     // QueryInterface for IDBSession::IDBSchemaRowset
  2387.     hr = pIDBCreate->QueryInterface( IID_IDBSchemaRowset,
  2388.                                     (LPVOID*)&pIDBSchemaRowset );
  2389.  
  2390.     if (FAILED(hr))
  2391.     {
  2392.         GetDetailedErrorInfo(hr, pIDBCreate, IID_IDBCreateCommand, "QI for IDBScemaRowset FAILED!!");
  2393.         goto error;
  2394.     }
  2395.     
  2396.     // Get a SchemaRowset back
  2397.     hr = pIDBSchemaRowset->GetRowset(
  2398.                             NULL,                        // punkOuter
  2399.                             rguidSchema,                // schema IID
  2400.                             0L,                            // # of restrictions
  2401.                             NULL,                        // array of restrictions
  2402.                             IID_IRowset,                // rowset interface
  2403.                             0L,                            // # of properties
  2404.                             NULL,                        // properties
  2405.                             (IUnknown**)&pIRowset);        // rowset pointer
  2406.  
  2407.     if (FAILED(hr))
  2408.     {
  2409.         GetDetailedErrorInfo(hr, pIDBSchemaRowset, IID_IDBSchemaRowset, "IDBSchemaRowset->GetRowset FAILED!!");
  2410.         goto error;
  2411.     }
  2412.  
  2413.     // Get Data from the IRowset Object
  2414.     hr = GetDataFromRowset( pIRowset );
  2415.  
  2416.     if (FAILED(hr))
  2417.     {
  2418. //        DumpErrorHResult( hr, (LPSTR)"GetDataFromRowset returned error!!" );
  2419.         goto error;
  2420.     }
  2421.  
  2422.     // Release Object
  2423.     pIDBSchemaRowset->Release();
  2424.     pIDBSchemaRowset = NULL;
  2425.     
  2426.     return;
  2427.  
  2428. error:    
  2429.     if( pIDBSchemaRowset )
  2430.         pIDBSchemaRowset->Release();
  2431.     
  2432.     return;
  2433. }
  2434.  
  2435.  
  2436. //**********************************************************************
  2437. // 
  2438. // CleanupRowset
  2439. // 
  2440. // Purpose:
  2441. //
  2442. //     Allows the rowset to perform any necessary cleanup.
  2443. //  
  2444. // Parameters:
  2445. //
  2446. //     IRowset*    pIRowset    - interface pointer on data provider's Rowset
  2447. //                            object
  2448. //     HACCESSOR     hAccessor   - accessor handle to release
  2449. // 
  2450. // Return Value:
  2451. //
  2452. //     S_OK        - Success
  2453. //     E_*         - Failure
  2454. //     
  2455. // Function Calls:
  2456. //     Function                    Location
  2457. // 
  2458. //     IRowset::QueryInterface     provider's Rowset object
  2459. //     IAccessor::ReleaseAccessor  provider's Rowset object
  2460. //     IAccessor::Release          provider's Rowset object
  2461. // 
  2462. //     assert                      c runtime
  2463. // 
  2464. //     
  2465. // Comments:      
  2466. //
  2467. //     In this sample, the only cleanup that the rowset needs to do is
  2468. //     release the accessor handle. 
  2469. // 
  2470. //**********************************************************************
  2471. HRESULT CleanupRowset
  2472.     (
  2473.     IRowset*    pIRowset,
  2474.     HACCESSOR     hAccessor
  2475.     )
  2476. {
  2477.     IAccessor*    pIAccessor = NULL;    // Pointer to an Accessor
  2478.     HRESULT        hr;                    // HRESULT
  2479.  
  2480.     // Assert    
  2481.     assert(pIRowset != NULL);
  2482.     
  2483.     if( hAccessor )
  2484.     {
  2485.         // Tell the rowset object it can release the accessor, via IAccessor
  2486.         hr = pIRowset->QueryInterface( IID_IAccessor, (void**)&pIAccessor );
  2487.  
  2488.         if (FAILED(hr))
  2489.         {
  2490.             GetDetailedErrorInfo(hr, pIRowset, IID_IRowset, "QI for IAccessor FAILED!!");
  2491.             goto error;
  2492.         }
  2493.  
  2494.         hr = pIAccessor->ReleaseAccessor( hAccessor, NULL );
  2495.         if (FAILED(hr))
  2496.         {
  2497.             GetDetailedErrorInfo(hr, pIAccessor, IID_IAccessor, "IAccessor->ReleaseAccessor FAILED!!");
  2498.             goto error;
  2499.         }
  2500.  
  2501.         pIAccessor->Release();
  2502.         pIAccessor = NULL;
  2503.     }
  2504.  
  2505.     pIRowset->Release();
  2506.     pIRowset = NULL;
  2507.  
  2508.     return S_OK;
  2509.     
  2510. error:    
  2511.     if( pIAccessor )
  2512.         pIAccessor->Release();
  2513.     if( pIRowset )
  2514.         pIRowset->Release();
  2515.  
  2516.     return hr;    
  2517. }
  2518.  
  2519.  
  2520. //**********************************************************************
  2521. // 
  2522. // DumpRow
  2523. // 
  2524. // Purpose:
  2525. //
  2526. //     Display the row to the screen.
  2527. //  
  2528. // Parameters:
  2529. //
  2530. // 
  2531. // Return Value:
  2532. //
  2533. //     
  2534. // Function Calls:
  2535. //     Function                    Location
  2536. // 
  2537. //     assert                      c runtime
  2538. // 
  2539. //     
  2540. // Comments:      
  2541. //
  2542. // 
  2543. //**********************************************************************
  2544. void DumpRow
  2545.     (
  2546.     DBBINDING*     rgBind,
  2547.     ULONG        cBind,
  2548.     ULONG        cMaxColWidth,
  2549.     BYTE*         pData,
  2550.     HWND        hList,
  2551.     DWORD        dwText,
  2552.     DWORD        addString
  2553.     )
  2554. {
  2555.     ULONG         iBind;            // Binding Count
  2556.     COLUMNDATA*    pColumn;        // Data Structure
  2557.     int            cb;
  2558.     CHAR        szTempString[MAXDISPLAYSIZE+10];    // Temporary Display Buffer, used to check data length
  2559.  
  2560.     // Asserts
  2561.     assert(rgBind);
  2562.     assert( offsetof(COLUMNDATA, wStatus) == 0);    
  2563.     
  2564.     // Print each column we're bound to.
  2565.     for (iBind=0, szDispBuffer[0]='\0'; iBind < cBind; iBind++)
  2566.     {
  2567.         // Columns are bound differently; not so easy.
  2568.         // Print out to at least DEFAULT_CBMAXLENGTH width (pretty),
  2569.         // Limit to first dwLength characters.
  2570.         pColumn = (COLUMNDATA *) (pData + rgBind[iBind].obStatus);
  2571.         
  2572.         // Check Status for NULL / OK / CANTCONVERT.
  2573.         switch (pColumn->wStatus)
  2574.         {
  2575.             case DBSTATUS_S_ISNULL:
  2576.                 strcat(szDispBuffer, (LPSTR)"<NULL>");
  2577.                 break;
  2578.             case DBSTATUS_S_OK:
  2579.             case DBSTATUS_S_TRUNCATED:
  2580.                 // Truncate if needed.
  2581.                 // - calculate number of bytes needed
  2582.                 cb = WideCharToMultiByte(CP_ACP, 0, (LPWSTR)pColumn->bData, -1,
  2583.                             NULL, 0, NULL, NULL);
  2584.                 if( cb > MAXCOLNDATALENGTH )
  2585.                 {
  2586.                     cb = WideCharToMultiByte(CP_ACP, 0, (LPWSTR)pColumn->bData, -1,
  2587.                         szTempString, MAXCOLNDATALENGTH, NULL, NULL);
  2588.                     
  2589.                     szTempString[MAXCOLNDATALENGTH] = '\0';  
  2590.                     strcat(szTempString, "...");
  2591.                 }
  2592.                 else
  2593.                 {
  2594.                     cb = WideCharToMultiByte(CP_ACP, 0, (LPWSTR)pColumn->bData, -1,
  2595.                         szTempString, (MAXDISPLAYSIZE+1), NULL, NULL);
  2596.                 }
  2597.  
  2598.                 if(pColumn->wStatus == DBSTATUS_S_TRUNCATED)
  2599.                     strcat(szTempString, "...");
  2600.                 strcat(szDispBuffer,szTempString);
  2601.                 break;
  2602.  
  2603.             case DBSTATUS_E_CANTCONVERTVALUE:
  2604.                 strcat(szDispBuffer, "<can't convert value>");
  2605.                 break;
  2606.             default:
  2607.                 {
  2608.                 CHAR szChar[10] = "";
  2609.                 strcat(szDispBuffer, "<unknown status of ");
  2610.                 strcat(szDispBuffer, itoa(pColumn->wStatus, szChar, 10));
  2611.                 strcat(szDispBuffer, ">");
  2612.                 }
  2613.                 break;
  2614.         }
  2615.  
  2616.         dwText = strlen(szDispBuffer);
  2617.         szDispBuffer[dwText++] = '\t';
  2618.         szDispBuffer[dwText] = '\0';
  2619.     }
  2620.     // Take the last \t off the end
  2621.     szDispBuffer[--dwText] = '\0';
  2622.     SendMessage(hList, addString, 0, (LPARAM)(LPSTR)szDispBuffer);
  2623.  
  2624. }    
  2625.  
  2626. //**********************************************************************
  2627. // 
  2628. // GetDetailedErrorInfo
  2629. // 
  2630. // Purpose:
  2631. //
  2632. //    Reads error from the error collection and displays it in messageboxes
  2633. //  
  2634. // Parameters:
  2635. //
  2636. //     HRESULT        hr                    - OLE DB HRESULT
  2637. //     IUnknown    *  pBadObject       - Object that caused an error
  2638. //  GUID        IID_BadInterface    - Interface that contains method that caused the error
  2639. //     LPSTR         lpStrBuffer            - Title Bar text
  2640. //
  2641. // Return Value:
  2642. //     
  2643. // Comments:      
  2644. //     If any sort of failure is encountered the return values will be NULL
  2645. //   strings. Therefore no extended error info will be printed.
  2646. //**********************************************************************
  2647.  
  2648. HRESULT GetDetailedErrorInfo 
  2649.     (
  2650.     HRESULT        hresult, 
  2651.     IUnknown    *pBadObject,                  
  2652.     GUID        IID_BadIntereface,                 
  2653.     LPSTR        lpStrBuffer
  2654.     )
  2655. {
  2656.     IErrorInfo *        pErrorInfo = NULL; 
  2657.     IErrorInfo *        pErrorInfoRec = NULL;
  2658.     IErrorRecords *     pErrorRecords = NULL;
  2659.     ISupportErrorInfo * pSupportErrorInfo = NULL;
  2660.     HRESULT             hr = S_OK;
  2661.     ULONG               i,ulNumErrorRecs;
  2662.     BSTR                bstrDescriptionOfError = NULL;
  2663.     BSTR                bstrSourceOfError = NULL;
  2664.     CHAR                szBuffer [512];  //Error Info Buffer
  2665.    
  2666.     // Check to see if this interface posts error messages
  2667.     if( SUCCEEDED( pBadObject->QueryInterface(IID_ISupportErrorInfo, 
  2668.         (LPVOID FAR*)&pSupportErrorInfo)) ) 
  2669.     {
  2670.         if( pSupportErrorInfo->InterfaceSupportsErrorInfo(IID_BadIntereface) == S_OK )
  2671.         {
  2672.             //Get Error Object. Return if no object Exists
  2673.             if( !SUCCEEDED(hr = GetErrorInfo(0,&pErrorInfo)) )
  2674.                goto DisplayHResult;
  2675.  
  2676.             // If returned a NULL error Object, then just display HR
  2677.             if( pErrorInfo == NULL )
  2678.                 goto DisplayHResult;
  2679.  
  2680.             //Get the IErrorRecord interface and get the count of error recs.
  2681.             if( FAILED(hr = pErrorInfo->QueryInterface(IID_IErrorRecords,(LPVOID FAR*)&pErrorRecords)) )
  2682.                goto DisplayHResult;
  2683.  
  2684.             //Retrieve the number of Error Records
  2685.             if( FAILED(hr = pErrorRecords->GetRecordCount(&ulNumErrorRecs)) )
  2686.                goto DisplayHResult;
  2687.  
  2688.             //Go through and print messages
  2689.             for(i=0; i<ulNumErrorRecs; i++) 
  2690.             {
  2691.                 if( FAILED(hr = pErrorRecords->GetErrorInfo(i, GetUserDefaultLCID(), &pErrorInfoRec)) )
  2692.                     goto Exit;
  2693.                 if( FAILED(hr = pErrorInfoRec->GetDescription(&bstrDescriptionOfError)) )
  2694.                     goto Exit;
  2695.                 if( FAILED(hr = pErrorInfoRec->GetSource(&bstrSourceOfError)) )
  2696.                     goto Exit;
  2697.  
  2698.                 sprintf(szBuffer, "HResult of 0x%0x (%ld) returned\nError Source: %S\nError Description: %S\n", 
  2699.                     (long)hresult,(long)hresult, 
  2700.                     bstrSourceOfError ? bstrSourceOfError : L"No Source Description",
  2701.                     bstrDescriptionOfError ? bstrDescriptionOfError : L"No Error Description");
  2702.  
  2703.                 MessageBox( NULL, (LPCTSTR)szBuffer, lpStrBuffer, MB_OK);
  2704.  
  2705.                 if (pErrorInfoRec)                
  2706.                 {
  2707.                     pErrorInfoRec->Release();
  2708.                     pErrorInfoRec = NULL;
  2709.                 }
  2710.                 if( bstrSourceOfError )
  2711.                 {
  2712.                     SysFreeString(bstrSourceOfError);
  2713.                     bstrSourceOfError = NULL;
  2714.                 }
  2715.                 if( bstrDescriptionOfError )
  2716.                 {
  2717.                     SysFreeString(bstrDescriptionOfError);
  2718.                     bstrDescriptionOfError = NULL;
  2719.                 }
  2720.             }
  2721.             
  2722.             // if we've process all the records we can go to end
  2723.             goto Exit;
  2724.  
  2725.         } //S_OK
  2726.     } //if (SUCCEEDED)
  2727.  
  2728. DisplayHResult:
  2729.     // In some error cases we may not have extended error information and it still would be good to
  2730.     // post the error HRESULT
  2731.     sprintf(szBuffer, "HResult of 0x%0x (%ld) returned, no Extended Error Information posted or supported", 
  2732.         (long)hresult,(long)hresult);
  2733.     MessageBox( NULL, (LPCTSTR)szBuffer, lpStrBuffer, MB_OK);
  2734.  
  2735.  Exit : 
  2736.     if (pErrorInfo)
  2737.         pErrorInfo->Release();
  2738.     if (pErrorRecords)
  2739.         pErrorRecords->Release();
  2740.     if( pSupportErrorInfo )
  2741.         pSupportErrorInfo->Release();
  2742.     if( pErrorInfoRec )
  2743.         pErrorInfoRec->Release();
  2744.     if( bstrSourceOfError )
  2745.         SysFreeString(bstrSourceOfError);
  2746.     if( bstrDescriptionOfError )
  2747.         SysFreeString(bstrDescriptionOfError);
  2748.  
  2749.  return hr;
  2750. } //PrintErrorInfo
  2751.  
  2752.  
  2753. //**********************************************************************
  2754. // 
  2755. // DumpErrorHResult
  2756. // 
  2757. // Purpose:
  2758. //
  2759. //     Dump the OLE DB HRESULT in a Message Box with a text Title Bar.
  2760. //  
  2761. // Parameters:
  2762. //
  2763. //     HRESULT        hr            - OLE DB HRESULT
  2764. //
  2765. //     LPSTR         lpStrBuffer - Title Bar text
  2766. //
  2767. // 
  2768. // Return Value:
  2769. //
  2770. //     
  2771. // Function Calls:
  2772. //     Function                    Location
  2773. // 
  2774. //     assert                      c runtime
  2775. // 
  2776. //     
  2777. // Comments:      
  2778. //
  2779. // 
  2780. //**********************************************************************
  2781. void DumpErrorHResult( HRESULT hr,     LPSTR lpStrBuffer )
  2782. {
  2783.     LPVOID    lpMessageBuffer;
  2784.  
  2785.     if(0 != FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER |
  2786.                 FORMAT_MESSAGE_FROM_SYSTEM,
  2787.                 NULL,
  2788.                 hr,
  2789.                 GetUserDefaultLCID(),
  2790.                 (LPSTR)&lpMessageBuffer,
  2791.                 0,
  2792.                 NULL))
  2793.     {
  2794.         MessageBox( NULL, (LPCTSTR)lpMessageBuffer, lpStrBuffer, MB_OK);
  2795.         LocalFree(lpMessageBuffer);
  2796.     }
  2797.     else
  2798.     {
  2799.         lpMessageBuffer = LocalAlloc(LPTR, 256);
  2800.  
  2801.         if( lpMessageBuffer )
  2802.         {
  2803.             sprintf((LPSTR)lpMessageBuffer, "HResult of %ld returned", (long)hr);
  2804.             MessageBox( NULL, (LPCTSTR)lpMessageBuffer, lpStrBuffer, MB_OK);
  2805.             LocalFree(lpMessageBuffer);
  2806.         }
  2807.     }
  2808. }
  2809.  
  2810. //**********************************************************************
  2811. // 
  2812. // NewIOpenRowsetWindow
  2813. // 
  2814. // Purpose:
  2815. // 
  2816. //     Create a new ICommand Object on the current IDBCreateCommand.
  2817. //     
  2818. // Parameters:
  2819. // 
  2820. // Return Value:
  2821. // 
  2822. // Function Calls:
  2823. //     Function                         Location
  2824. // 
  2825. //       IDBCreateCommand::CreateCommand    provider's Command object
  2826. //     ICommand::Release                provider's Command object
  2827. //        
  2828. //     
  2829. // Comments:      
  2830. // 
  2831. // 
  2832. //**********************************************************************
  2833. void FAR PASCAL NewIOpenRowsetWindow()
  2834. {
  2835.     int                 nCurrenthdbc;            // Current PROVIDER
  2836.     char                szBuffer[MAXBUFLEN+1];    // String in PROVIDER ComboBox on Toolbar
  2837.     char                szProvName[MAXBUFLEN+1];// DSN String
  2838.     MDICREATESTRUCT        mcs;                    // MDI Child Window Create Struc
  2839.     
  2840.     IOpenRowset *         pIOpenRowset= NULL;        // IOpenRowset Object
  2841.  
  2842.         
  2843.     // check if there is PROVIDER selected in the Combo-Box
  2844.     if ((nCurrenthdbc = (int)SendMessage(hWndCrsrList, CB_GETCURSEL, 0, 0)) == CB_ERR)
  2845.     {
  2846.         MessageBox(hWndFrame, MAKECONNECT, NOSESSIONERROR, MB_OK | MB_ICONHAND);
  2847.         return;
  2848.     }
  2849.     
  2850.     // check if the number of windows exceeds MAXCHILDWNDS
  2851.     if (nChildCount >= MAXCHILDWNDS)
  2852.     {
  2853.         MessageBox(hWndFrame, MAXCHILDEXCEEDED, MAXCHLDERR, MB_OK | MB_ICONHAND);
  2854.         return;
  2855.     }
  2856.  
  2857.     // Scan PROVIDER string and IDBCreateCommand value from the combo-box
  2858.     SendMessage(hWndCrsrList, CB_GETLBTEXT, (WPARAM)nCurrenthdbc, (LPARAM)(LPSTR)szBuffer);
  2859.     
  2860.      sscanf(szBuffer, SCANPROVIDERSESSION_FORMAT, szProvName, &pIOpenRowset);
  2861.  
  2862.     // create a new MDI client window. maximized, if the previous is so.
  2863.     mcs.szClass = OLEDBMDICLASS;
  2864.     mcs.szTitle = UNTITLED;
  2865.     mcs.hOwner  = hAppInstance;
  2866.     mcs.style   = hWndActiveChild && IsZoomed(hWndActiveChild) ? WS_MAXIMIZE : 0;
  2867.     mcs.x = mcs.cx = mcs.y = mcs.cy = CW_USEDEFAULT;
  2868.     hWndActiveChild = (HWND)(UINT)SendMessage(hWndMDIClient, WM_MDICREATE, 0, (LPARAM)(LPMDICREATESTRUCT)&mcs);
  2869.         
  2870.     // check if it was created, if it wasn't free up resource and flag warning
  2871.     if (!hWndActiveChild)
  2872.     {
  2873.         MessageBox(hWndFrame, CREATECHILDERR, EXECERROR, MB_OK|MB_ICONEXCLAMATION|MB_TASKMODAL);
  2874.         return;
  2875.     }
  2876.         
  2877.     // Display the Provider string, PROVIDER and IOpenRowset in the title
  2878.     // of newly created window. Increment the child window counter
  2879.     wsprintf(szBuffer, QUERY_STRING, pIOpenRowset);
  2880.         
  2881.     SendMessage(hWndStmtList, CB_ADDSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  2882.     SendMessage(hWndStmtList, CB_SELECTSTRING, 0, (LPARAM)(LPSTR)szBuffer);
  2883.     
  2884.     wsprintf(szBuffer, PROVIDER_SESSION_COMMAND_FORMAT, (LPSTR)szProvName, pIOpenRowset, NULL);
  2885.     
  2886.     SetWindowText(hWndActiveChild, szBuffer);
  2887.     nChildCount++;
  2888.     
  2889.     // Update the Command Combo-Box on the tool bar.
  2890.     ChangeCurrentICommand(hWndStmtList);
  2891. }
  2892.  
  2893.  
  2894.  
  2895.  
  2896.