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- SUPERBASE PERSONAL
-
- Ported from an AMIGA disk to the ST and back again. Edited by Parasite.
-
-
- PART 1
-
- WELCOME TO SUPERBASE
-
- This Introductory session with Superbase will give you an understanding of
- how to perform some of the basic database operations of the Superbase system.
- Some more complex functions are explained in the section Working with
- Superbase.
-
- We'll assume you know how to do a number of things which are either essential
- to the ST operating system or common to almost all ST programs:
-
- Switching on the power.
- Using the mouse to point, click on Icons or menu items, and drag Icons or
- windows around the screen.
- Resizing windows.
-
- If you don't know how to do any of these, refer to the ST User Guides.
- In addition, you should have a thorough understand of elementary file
- operations, such as copying files, renaming files and deleting files.
-
- THE SUPERBASE MENUS
-
- The Superbase menus are obtained in the same way as for all ST GEM based
- programs. Move the mouse to the title-bar and the menu will appear.
- Simply click on the appropriate item.
-
- GHOSTED ITEMS
-
- A standard intuition feature is the "ghosting" of menu items that are
- temporarily unavailable. We use this feature in Superbase, most obviously
- during this start up phase when no file is open.
-
- To see this, move the pointer to the menu bar, and move the pointer across
- until it's on the work Record. You'll see that all the items on this menu
- appear to be faint, as if only half the dots that make up each letter were
- being used. If you try to select a ghosted item, nothing will happen.
- A quick look at the Control Panel at the bottom of the screen will reveal
- the most of the control buttons are also ghosted while no file is open.
-
- OPENING A FILE
-
- If you look at the top left-hand corner of the screen you will see a message
- that reads "Superbase: Please open a file". You always see this message
- when you start Superbase up, or when there is no file open. Since you can't
- do any work without a file, let's open one and take a look at it.
-
- Files can only be opened from the Project menu. This is the first menu on
- the menu bar.
-
- Move the mouse pointer to the top of the screen so that it highlights the
- work Project. As you do this the Project menu appears. The item you
- want is open. Move the pointer down the menu, and highlight open. As you
- do so, you'll see four subitems appear to the right, three of which,
- Fields, Index, and Query are ghosted. The only one available is File
- which is the one you want to select. So, keeping Open highlighted,
- move the pointer slowly to the right until the File subitem is also
- highlighted. Now, press the left mouse button, and the item is selected.
- All menu items are selected in the same way, and we won't give detailed
- instructions for the dozens of menu selections discussed elsewhere in the
- manual.
-
- SUPERBASE REQUESTERS
-
- Superbase now requestes the name of the file you wish to open. Requesters
- like this one (some are more complicated) are used in most Superbase
- operations. They also communicate messages to the user. They are
- known as requesters because their function is to request specific action
- from the user. Usually the action involves making selections by clicking
- the mouse or typing in a number of a text value of some kind.
-
- Many requesters show a panel that contains a list of items such as file
- name or field names. The panel may be only a few lines long, so there may
- be more files or fields than can be shown at one time. If there's
- a gap at the bottom of the scroll bar there are more items to be viewed.
- You can show them by dragging down the scroll bar at the right of the
- panel, or by clicking on the downwards pointing arrow gadget below the
- scroll bar.
-
- One very important fact about requesters is that you must respond to them
- before you can do anything else. Most requesters have a Cancel button.
- Clicking on this returns you to whatever you were doing previously. If
- there's no Cancel button there is certain to be an OK button, and you can
- safely click on this once you've read the requester.
-
- Many Superbase requesters include a Clear button. This has the effect of
- removing anything that's in the Selection Box, and can be used at any time.
-
- CHOOSING THE ADDRESSES FILE
-
- Move the pointer into the panel which contains a list of file names.
- Move it over the file name Addresses. This is the demonstration file
- you'll be using for the rest of this session. Using the left-hand button,
- click once on the name Addresses. Superbase copies the name of the file
- you've selected into the Selection Box -- that's the box underneath the
- panel of tile names. (If you see the wrong file name in the box, move the
- pointer carefully onto the right file name, and click again.) Once
- you've selected the file, move the pointer onto the OK button and click
- once. Superbase now opens the Addresses file.
-
- THE MAIN DISPLAY
-
- When Superbase opens a file from the start up screen, it automatically reads
- the first record in the file and shows it on the Main Display screen.
- You'll see the name of the file appear on the title bar at the top of the
- window, followed by the name of the field on which the file is currently
- indexed.
-
- The Main Display is Superbase's permanent window onto your database. It's
- like a large worksheet, 273 colulmns across; the number of lines you can see
- depends on the size of your window. Surperbase uses the Main Display
- to show you the records in the current file, as well as the results of some
- other operations. At the bottom of the Main Display is the Control Panel,
- which we'll be looking at in a minute.
-
- On the Main Display, the field names for each record in the Addresses file
- appear down the left-hand side of the screen. The data for each field is
- displayed to the right of its field name. If the data for a field is
- wider than the window, it extends off to the right. You can bring it into
- view using the scroll bar at the bottom of the window.
-
- Remember that if there were more fields in the record than you could see,
- you could view them by dragging the scroll bar at the right of the window
- downwards, or by clicking on the downward pointing arrow.
-
- RECORD VIEW, FORM VIEW AND TABLE VIEW
-
- The record format you're looking at now is only one of the three possible
- ways of looking at your file. It's called Record View. This view shows
- the records one at a time, restricting the format by keeping the field
- names on the left and limiting you to one field per line. This restriction
- allows records to be scrolled up and down the screen with the Control
- Panel buttons.
-
- In Form View, you also see one record at a time. Each record is like a
- form or page and, as you'll see later, you can drag the fields around to
- create a worksheet desinged to suit your application.
-
- The third display format is Table View. This displays the field names
- across the top of the screen with the data appearing in rows and columns,
- each record occupying one line.
-
- SWITCHING TO TABLE VIEW
-
- Select Table View from the Set Menu. You will see the field names appear
- across the top of the screen. The same record is shown, but each item of
- data appears underneath its field name. As with Form View, there are ways
- of changing this row and colulmn display to suit your own preferences which
- we'll explain later.
-
- SCROLLING THE SCREEN
-
- While you are viewing your record in Table View you will notice that the
- field names do not all fit onto the screen. The fileds to the right can be
- viewed using the arrow at the right of the bottom scroll bar. Move the
- pointer onto this arrow, and click on it once. The display shifts five
- columns to the left. Click once on the left-hand arrow to shift right
- and restore the display. If you want to shift the display by larger areas,
- drag the bottom scroll bar with the mouse.
-
- CONTROL PANEL
-
- Now that you've opened a file, and discovered how to change the way in
- which records are displayed on the screen, let's look at the Control Panel.
- This is your means of controlling the main display. As you can see there
- are 12 buttons, most of them modelled on the controls for a video cassette
- or tape recorder, so you should find these conventions easy to learn and
- remember.
-
- Each button has a special purpose, and together they fall into three groups.
- On the left are the Pause and Stop buttons. Followed by seven buttons for
- browsing through the file. On the right are three special purpose
- buttons which we'll examine later. The functions of some controls are more
- intuitively obvious than others, so we'll take a look at the first nine
- now, one by one. Make sure you've set Table View for this exercise.
-
- ^ Current Record: This button is used to display the current record.
- When Table View has put a lot of records on the screen it can be helpful
- to select the current record as the top record in the display. Also, you
- can only Edit the current record, and this button is a useful way of
- ensuring that you've got the right record. If you click on this button
- you will notice that Superbase clears the screen and then displays the
- current record.
-
- > Next Record: Allows you to view the next record in the file. The order
- in which the records appear is decided by the current index, which is shown
- by the message on the title bar of the main display window. Try this
- now, and you'll see the data for the next record come onto the screen. In
- Table View it appears underneath the previous record. In Form View it
- replaces the previous record.
-
- < Previous Record: This gets the previous record in the file, relative to
- the current record.
-
- >> Fast Forward: Instead of moving forwards through the file one record
- at a time by pressing the Next button, you can move much quicker using the
- Fast Forward button. Click on this button, and Superbase gets the next
- records in the file, displaying them row by row until the screen is full,
- when it selects the Pause button.
-
- || Pause: When the Pause button is selected, you cannot select any menu
- item until you either release it or click on the Stop button next to it. You
- can, however, use the other Control Panel buttons. So, to view the next
- screen of records, release the pause by clicking on the Pause button.
- Superbase continues with the Fast Forward display of records, stopping when
- the next screen is full, or when it reaches the end of the file. Pause is
- useful when you're searching for a record and you want to stop from time to
- time to read the screen.
-
- << Rewind: This does the opposite of the Fast Forward button. You will see
- the data appear from the top of the screen,in reverse index order. If you do
- this immediately after Fast Forward there will be an apparent delay while
- Superbase displays records over the text of the existing display.
-
- |< First: Pressing this button automatically displays the first record in
- the file, according to current index order.
-
- >| Last: Pressing this button automatically displays the last record in
- the file, according to current index order.
-
- | Stop: If you want to stop the Fast Forward or Rewind display, click on
- Stop. You must also click on Stop if you want to interrupt Pause when it's
- selected.
-
- OPENING FIELD TO VIEW
-
- As Superbase imposes no limit on the number of fields per record, you need
- to have a way of restricting the fields that actually appear on the Main
- Display. You can do this with the Open Field option on the Project Menu.
-
- Display the Project Menu, and select Open Fields. The basic procedure for
- selecting fields is very simple:
-
- 1. Click on a field name in the left-hand panel. Superbase copies it
- into the right-hand panel.
- 2. Repeat until the selection of fields you want is in the right-hand
- panel.
- 3. Click on OK.
-
- The list of fields in the right-hand panel is called the Open Fields List.
- Let's make one now. Move the pointer onto the list of fields names, and
- click on City. Notice how Superbase copies it across. Now click on
- Lastname. When you have both names in the list, click on OK. (If you make
- a mistake, DEL removes the current field from the right-hand panel; Clear
- removes the whole list.)
-
- Superbase immediately returns to the Main Display showing the data for the
- two open fields. Try out the Control Panel buttons to see their effect.
- Experiment with Record View as well as Table View.
-
- When you've finished, restore the full set of fields by selecting Close
- Fields from the Project menu.
-
- PAGING
-
- This is another feature which gives you control over the Main Display:
- the Paging option.
-
- If Record View is not set, select it now from the Set Menu. Then go back
- to the Set menu, and move the pointer down to the Paging item, which should
- have a check mark against it. Release the mouse button while Paging is
- highlighted. You've now turned the paging option off. (You can check this
- by looking at the Set menu again; there should be no check mark against the
- Paging item.)
-
- Now, select the first record in the file by clicking on the First Record
- button. Then click on Fast Forward, and watch the display. You'll see that
- Superbase doesn't pause when the screen is full -- It just goes on
- displaying records. You can still use pause to halt the display, but the
- automatic pausing at the end of each "page" of data no longer occurs. The
- same applies when Rewind is in use, except that the records appear at the
- top of the screen.
-
- If you now switch back to Table View and try out some of the Control Panel
- buttons, you'll see that with Paging off the difference is similar to that
- in Record View. Each record appears below the last, without clearing the
- screen. Rewind displays records from the top down, as in Record View.
-
- MOVING COLUMNS
-
- For this exercise you need to be able to see all the fields on the screen,
- not just those in the Open Fields list, so if you have an open Fields list
- in use, close it now by selecting Close Fields from the Project Menu.
-
- You can see that if you have all the fields open in Table View, some of
- the field data is very likely to be hidden from view. Normally, to see
- hidden fields you have to scroll the screen to the right. However, Superbase
- provides a way of closing up columns to get more data on the screen.
-
- Assuming you're in Table View -- set it if you're not -- click on the First
- button, then the First Record button on the Control Panel in order to get
- the first record of the Addresses file on your screen.
-
- MOVING A COLUMN TO THE LEFT
-
- Now move the pointer so that it is on the space to the right of "M" in the
- Title Field. Once you have done that press and hold down the left-hand
- button of the mouse. As you do this you will see two vertical lines
- appear, forming a column beneath the Title field. There are also lines
- extending off to the right of the screen.
-
- Keeping the left button depressed, drag the pointer a little to the left,
- then release the mouse. You will see that the column moves, and when you
- release the mouse the data beneath the field name has shifted to the left.
- All columns to the right have also moved leftwards.
-
- Now try the same with the Forename field. This time over the column so that
- it is just to the right of the "e" in Title. If you also try this with
- Lastname and Street you will see that as you move the columns over to the
- left the field name City appears on the right of the screen.
-
- If you now move the City column to the left, the Code field will appear on
- the screen. Finally, if you move the Code field, Country will appear on the
- right-hand side. So by moving the columns you've got all the fields on one
- screen instead of two.
-
- Notice that you can move a column so that it overlaps the column to its left,
- truncating the data. This can be useful.
-
- MOVING A COLUMN TO THE RIGHT
-
- If you move a column back to the right, the truncated field name and data are
- not automatically restored to their full length. A quick way of restoring the
- length of a field is to double click in its column. Then if you click on the
- Current Record button the full field name and data will reappear. But as this
- only displays one record you will have to use Fast Forward if you want to
- redisplay a screen of Record data.
-
- FORM VIEW DESIGN
-
- Superbase allows you to rearrange the positions of the fields in Form View,
- setting more than one field on a line, creating columns of field to resemble
- invoices or other business forms, and generally talloring the system to
- suit your own application. The full 273 column woeksheet is available for
- Form View, and you can vary the depth by dragging fields downwards, creating
- new lines.
-
- You can use Form View for creating new records and editing them, as well as
- for display. By setting the Printer option on, you can copy the visible
- portion of the worksheet to the printer.
-
- Select Form View now from the Set Menu.
-
- Make sure you've got the Addresses file open, and that the current record is
- the first record in the file.
-
- DEFAULT FORM VIEW
-
- If you look at the screen you can see that the fields names already appear
- in a Form View. This is the default Form, which we have predefined for this
- demonstration file. You can change it, and then save it with Project
- Save File. Once a Form has been saved, the fields will appear in that
- layout every time you open the file.
-
- MOVING FIELDS
-
- Let's move the Lastname field to another position on the screen. Move the
- pointer so that it's on the field name Lastname. Then press and hold down
- the left-hand button of the mouse. Superbase outlines the field name and
- its data area. (If you see a cursor instead, you've started editing by
- mistake. Carefully click again on the field name itself.) Now drag the
- outlined box to a new position two lines above its present position.
- Release the mouse button. As you can see, the field name and data have
- moved to this new position.
-
- Now, if you want to, you can arrange the Form View for Addresses in any way
- you like. This can be just an experiment, but if you want to save the
- present arrangement, you can do so. Select Save File from the Project
- Menu. Superbase stores the File Definition, which contains the Form View
- location of each field, on disk.
-
- Although you have freedom to drag fields to any position on the screen,
- there are as usual a few limits to what you can do.
-
- You cannot place a field on top of either the name or the data area of
- another field. If you try this, Superbase leaves the field you tried to
- drag in its original position.
-
- Superbase won't let you move a field off the right or left-hand end of the
- worksheet.
-
- To gain more lines, move a field down into the Control Panel. Then use the
- vertical scroll bar on the Main Display window to bring it back into view.
- Move it down again if you still need more lines.
-
- To move a field over to the right of the worksheet, position it near the
- right-hand edge of the screen, then shift the display with the scroll bar,
- and drag the field further over.
-
- Only the open fields are shown, so close the Open Fields List if you want
- to see all the fields in Form View.
-
- Finally, a small but entertaining feature. Select Fast Forward, and drag
- the fields around as described above. No problem.
-
- SUMMARY
-
- Time for a check list of what you should know before we proceed.
-
- * How to open a file
- * How to switch between Form View, Table View, and Record View
- * How to switch Paging off and on
- * How to drag columns around in Table View
- * How to Open and Close a list of fields
- * How to select the Current record
- * How to move to the First record
- * How to move to the Last record
- * How to move to the Next record
- * How to go to the Previous record
- * How to use the Fast Forward to move forwards through the records
- * How to Rewind to move backwards through the file
- * How to Pause
- * How to Stop
-
- Understanding all these actions is essential if you want to be able to work
- easily with Superbase. If you do not understand them or are uncertain then
- take a little time to go back and re-read the appropriate sections before
- continuing.
-
- THE KEY LOOKUP BUTTON
-
- ? Key Lookup: This is for the retrieval of individual records. You enter
- a value for the field on which the file is currently indexed, and Superbase
- uses the index to find and display the record. You can only use one index
- field at a time -- the Filter button is used for multiple value searching.
-
- When you click on the Key Lookup button you'll see a requester for the
- entry of a key value.
-
- TYPING IN YOUR KEY
-
- To be able to type in the box, you must move the pointer into it and click
- the mouse once. This produces the cursor, and you can then type in your
- Index Key.
-
- Suppose you want to find the record for Julie Kasper. The file is indexed on
- the Number field, so we can use the current index to search for individuals
- by their Reference Numbers. Click in the box and then type in "KAS0001"
- (omit the quotation marks). This is the Index Key.
-
- RETRIEVING THE RECORD
-
- When you press Return or click on OK, Superbase looks up the first record
- for which the Number field has the value "KAS0001". If there were more than
- one with this value, you would have to browse through the file with the
- Next Record or Fast Forward button to find the exact record you wanted.
-
- KEY LOOKUP WITH A DIFFERENT INDEX
-
- You're not restricted to one index. Superbase allows you to have up to 999
- indexes for each file, all automatically updated when you add or modify
- records. We've provided indexes on the other fields besides the number
- field: Lastname, City and Country. Let's try one of these. Select Open index
- from the Project Menu.
-
- Click on the field name Lastname; this is copied into the Selection Box.
- When you're ready, click on OK. You've selected the Lastname index, and if
- you look at the title bar at the top of the window you'll see that the
- message now reads "Superbase: Addresses Indexed on Lastname".
-
- The record on the main display has not changed. Click on the Key Lookup
- button, and Superbase produces the Record Key requester. As you did above,
- click in the box and type in a key value, only this time type in "Forge".
- Press Return or click on OK, and Superbase looks up the first record with
- Forge in the Lastname field.
-
- ENTERING PARTIAL VALUES
-
- You don't even need to type the full index key in many cases. Try Key
- Lookup once more, but type in "Hut" and press Return. Superbase finds the
- first record for Huttermann. For your information, Superbase tells you
- that it didn't find the exact match.
-
- THE FILTER BUTTON
-
- = Filter: This is a very powerful feature. You may have thousands of
- records in a database file, yet you may often want to review them (or print
- them out) on a selective basis. The Filter allows you to enter a set of
- values, as simple or a comprehensive as you like, to restrict the display to
- only the records that match those values.
-
- THE FILTER REQUESTER
-
- Move the pointer and click on the Filter button on the Control Panel. This
- requester looks more complex than the ones you have seen so far, but after
- a little practice with the demonstration file you'll find that you can
- remember how to use it easily. It's important that you learn how to use the
- Filter, because Superbase uses filters in several other functions.
-
- The requester has four main parts: the Field Name Panel, the Operators, the
- Value Box, and the Main Box. A Filter is created by a combination of
- clicking on field names and operators and typing in values. These actions
- produce the Filter Command Line in the Main Box. Let's look at each
- component of the Filter Requester in turn.
-
- FIELD NAME PANEL
-
- This appears on the left-hand side of the requester. You can scroll the
- list of field names up and down in the usual way, using the scroll bar and
- arrows at the right of the Field Name Panel. You specify that a field is
- to be used in the Filter by clicking on its name in this panel.
-
- The list of field names is complete. It's not affected by whether you have
- an Open Fields List, so the fields that specify the Filter neen not be the
- same as the ones that are shown in the Main Display.
-
- OPERATORS
-
- These appear to the right of the Field Name Panel, and can be divided into
- the Relational Operators, Logical Operators and Mathematical Operators.
- We'll see how these are used below.
-
- VALUE BOX
-
- This is the box with the word "Value" next to it. You use it for typing in
- values such as names, numbers, and dates, which will form part of the
- Filter.
-
- Always remember to press Return after typing in the Value Box. You must do
- this to ensure that the contents are copied to the Main Box.
-
- MAIN BOX
-
- This is the long box that appears below the Field Name Panel and extends
- across the whole requester. When you make selections with the mouse or type
- values into the Value Box, Superbase copies them into the Main Box,
- building up the Filter Command Line. In this way you get immediate feedback
- about the results of your selections. The maximum length of the Filter
- Command Line is much greater than the apparent length of the box -- up to
- 255 characters are allowed. You can type directly into the Main Box, but
- in these exercises we'll stick to making selections with the mouse.
-
- USING THE OPERATORS
-
- The Operators are the most complex aspect of the requester. They are used
- to relate field names to other fields or values. For example, if we wanted
- to set up a Filter to show only the addresses in West Germany, we would
- need the expression: Country LIKE "West Germany". Here, Country is a field
- name obtained by clicking in the Field Name Panel; LIKE is selected by
- clicking on the LIKE Operator button; and "West Germany" is typed into the
- Value Box.
-
- TEXT STRING AND PATTERN MATCHING: LIKE
-
- When you're searching for names or text strings, uyou should avoid using
- the equals sign operator, and use LIKE instead. This is because only LIKE
- accepts matches on either upper or lower case characters; it's said to
- be "case insensitive". The equals sign operator, on the other hand,
- requires exact matches for what you type in: It is "case sensitive".
-
- LIKE also permits searches for text strings that include pattern matching
- characters. These allow you to enter incomplete words for the Filter. For
- example, to find all the records where the Lastname begins with "C" you
- need the Filter Command Line: Lastname LIKE "C". To specify a range add
- square brackets to the value: Lastname LIKE"[A-D]*"; this finds all the
- records where the Lastname begins with "A", "B", "C", or "D". Note that
- the Asterisk is placed outside the brackets.
-
- There are several other things you can do with the LIKE operator. You'll
- find a complete list and a number of examples in Appendix B.
-
- THE RELATIONAL OPERATORS
-
- = This specifies that the field is to be EXACTLY EQUAL TO the following
- value or field: Balance = 2000.
-
- <> The field is to be NOT EQUAL TO the following value or field:
- Country <> "France".
-
- > The field is to be GREATER THAN the following value or field: Balance
- > 1000.
-
- < The field is to be LESS THAN the following value or field: Balance <
- 1000.
-
- >= The field is to be GREATER THAN OR EQUAL TO the following value or
- field: Balance >= 1000.
-
- <= The field is to be LESS THAN OR EQUAL TO the following value or
- field: Balance <= 1000.
-
- THE LOGICAL OPERATORS AND, OR AND NOT
-
- These provide links between different expressions like the ones given
- above. You use them to specify alternatives and ranges for the Filter,
- either for a single field or for a number of interrelated fields:
-
- AND Both of the conditions linked by AND must be satisfied for the record
- to be accepted by the Filter: Country "West Germany" AND Balance >=
- 5000.
-
- OR Either of the conditions linked by OR is sufficient to make the record
- acceptable to the Filter: Country LIKE "West Germany" OR City LIKE
- "Geneva".
-
- NOT NOT is slightly different. It negates the effect of an expression:
- NOT (Country LIKE "West Germany" AND Balance > 5000). This will find all
- the records other than the ones where the country is West Germany and the
- balance is greater than 5000. Note the use made of Parentheses with NOT.
-
- PARENTHESES
-
- The ( and ) operators are used in the normal way, to give priority to one
- part of the expression over another.
-
- ( The following expression has a higher priority for evaluation than the
- preceding expression.
- ) Required to end a higher priority expression.
-
- The numbers of opening and closing parentheses must be equal.
-
- THE MATHEMATICAL OPERATORS
-
- + This is used to express addition: Balance > Amount + 1000.
-
- - The minus sign expresses subraction: Balance > Amount - 1000.
-
- * The asterisk is used for multiplication: Balance > Amount * 1.15.
-
- / The slash represents division: Balance < Limit / 10.
-
- TYPING IN THE MAIN BOX
-
- The great power and flexibility of the Filter system is only achieved by
- giving the user control of every aspect of the operation. Because you
- type into the Main Box you include all kinds of expressions which are not
- available from the buttons on the requester itself, and all kinds of text
- and numeric values.
-
- The price you pay for this flexibility is an increased risk of making
- mistakes. This is not too serious, as you cannot harm your data by using
- a Filter (although you can discard records using the Remove Records Filter).
- However, you may see a Superbase "Can't do this" message concerning an
- error in the Filter Command Line in two possible situations:
-
- When you click an OK after creating or editing a Filter Command Line.
-
- When you use a Filter after changing the definition of a field with
- Project Edit.
-
- If you see a "Can't do this" message you must either change the Filter
- Command Line or change the file definition. Here's a summary of the
- editing facilities available when typing inside the Main Box:
-
- FILTER COMMAND LINE EDITING
-
- You can remove everything from the Main Box by clicking on the Clear
- button.
-
- If you have clicked in the box, hold down the Alternate Key and press X
- to delete its contents. (Note: we refer to this key combination as
- Alternate-X).
-
- Provided you have not left the box -- the cursor is still visible --
- Alternate-Q will restore the contents you deleted with the Alternate-X.
- This does not work after clicking on Clear.
-
- If Superbase won't let you make an Operator selection when you return to
- modify an existing Filter Command Line, click in the Main Box and press
- Return. Now you can go ahead.
-
- Shift key and cursor right arrow and shift key and cursor left arrow move
- the cursor to the end and beginning of the Filter Command Line
- respectively.
-
- The DEL key romoves the character to the left of the cursor. Backspace
- repeats its action if held down.
-
- USING A FILTER
-
- The Filter Command Line is made active by clicking on OK. Whenever a Filter
- is in use, Superbase highlights the Filter button on the Control Panel. You
- can perform all but one of the Control Panel record selection operations
- we've discussed, and Superbase will restrict the records displayed to the
- ones that match the Filter values. For example, if you have specified the
- Country LIKE "West Germany" and you click on the First Record button,
- Superbase will go and find the first record in the file, according to the
- current index, which has the value "West Germany" in the Country field.
-
- The Key Lookup button is an exception to the filter effect. You can still
- recall individual records by entering an index key value, whether or not
- they match the Filter.
-
- SUSPENDING A FILTER
-
- There wil be times when you want to remove the Filter effect so that you
- can review all the records in the file again. To do this, just click on the
- highlighted Filter button. It reverts to normal, and you'll find that when
- you use the Control Panel Superbase acts as if there were no Filter.
-
- MODIFYING OR RE-ACTIVIATING A FILTER
-
- If you've set up a Filter and then suspended it, you can bring it back into
- operation by clicking once more on the Filter button. Superbase displays the
- Filter requester, with the Filter Command Line in the Main Box just as you
- left it.
-
- If you want to, you can add to the Filter Command Line by clicking on more
- field names and operators (you may need to click in the Main Box and press
- Return first), or edit it after clicking in the Main Box, as described
- above.
-
- Whether you've made any changes or not, just click on OK to use the Filter
- again.
-
- FIFTEEN MINUTE TUTORIAL
-
- Make sure you've got the Addresses file open, indexed on Lastname. Set Table
- View with Paging off. Go into Project Open Fields and open these fields:
- Forename
- Lastname
- Street
- City
- Country
-
- In Table View, drag the Lastname column a few columns to the left, and then
- do the same for City, overlapping the Street column if necessary, until the
- Country column comes into view.
-
- Click on the Filter button.
-
- We are going to search for those name and address records where the person
- lives in the USA or West Germany. So we'll use the Country field, and LIKE
- operator, and the Value Box. You'll see the results of your selections
- appear as a Filter Command Line in the Main Box.
-
- Move the pointer into the Field Names Panel, and click once on the down
- arrow to bring Country into view. Then click on Country. The name appears
- in the Main Box. Next, move the pointer to the right and click on the
- LIKE button. This also appears in the Main Box. Now you must type in "USA".
- This goes in the Value Box. Move the pointer into the Value Box and click
- on the mouse to produce the cursor. Type in "USA" (no quotation marks).
- Press Return -- this is essential, or the contents of the Value Box will
- not be copied into the Main Box. Your Filter Command Line should read:
-
- Country LIKE "USA"
-
- Next, you need the OR operator. Click on it and Superbase copies it into
- the Main Box. Now you must click on the Country field name again. This is
- important. A Filter Command Line like this is not allowed:
-
- Country LIKE "USA" OR "West Germany"
-
- So, click on Country, as before, followed by LIKE. Then, as before, click
- in the Value Box, and type in "West Germany". Press Return. Your Filter
- Command Line should look like this:
-
- Country LIKE "USA" OR Country LIKE "West Germany"
-
- If there are any mistakes click on Clear and repeat the steps above until
- you get it right.
-
- You have built your Filter Command Line, so now you can put it into action.
- Click on the OK button. Superbase activates your Filter and displays the
- first record in the file that matches the Filter. Click on Fast Forward.
- Superbase shows all the records that match the Filter.
-
- Now de-activate the Filter. Click on the Filter button so that it's not
- highlighted. Now click on Rewind. You'll see all the records in the file
- appear as normal.
-
- Let's go back and add another condition. Click on the Filter button to
- recall the requester. Click on the OR operator, then on Country, then on
- LIKE, then in the Value Box, type in "France", and press Return. Your line
- should read:
-
- Country LIKE "USA" OR Country LIKE "West Germany" OR Country LIKE "France".
-
- Now click on OK and when Superbase shows the first record, click on Fast
- Forward. You will see that Superbase has added the addresses in France to
- the display.
-
- That concludes our short tutorial.
-
- OTHER FILTER BASED OPTIONS
-
- You should have acquired a feel for the way the Filter requester works, and
- you can experiment freely with the Addresses file to deepen your knowledge.
- When you're ready, you can start using the Process options, all of which
- are selected from the Process menu.
-
- Remove: Allows you to delete groups of records from the file. You can use
- the Control Panel Filter to view them first -- the Filter Command Line is
- preserved for you to use in the other Filter functions.
-
- Import: When you need to read in records from other systems, the import
- Filter provides a means of rejecting records that don't match the conditions
- you set up.
-
- Export: The opposite of Import, Export lets you create a disk file
- containing selected fields and records.
-
- Print: A quick and easy way of obtaining a permanent list of all the
- information contained in the selected fields and records.