H4CK3R 4/hacker04/04_HACK04.ISO/src/PHP/classquery.php3.txt

Text File | 2002-05-06 | 7.5 KB | 229 lines

Class QueryGenerator

Generates select query strings for a MySQL (may work on others!) database search.Currently supports case sensitive and fullword match. This class can be easily extended to make a search engine class.


<?php

/*****************************************************************************
 Class Query v.1.1
******************************************************************************

 Author: [e-mail]

 Purpose:

        To add a logical query to the SearchEngine class. The logic can be
        one of the following : AND , OR, NOT.

 Usage:
        aquery = new Query("NOT", array("apple", "pear", "bannana"));

*****************************************************************************/

class Query {

//PRIVATE:

    var $m_words;
    var $m_logic;

//PUBLIC

     //
     // Constructor

     // logic: <AND | OR | NOT>
     // words: words to be searched for given logic

    function Query($logic, $words) {

        $this->m_words = $words;
        $this->m_logic = $logic;
    }

     // print attributes of query

    function p() {

        echo  "$this->m_logic";
        reset($this->m_words);
        while(list($i, $word) = each($this->m_words))
            echo  ":$word";
    }
};

/*****************************************************************************
 Class QueryGenerator v.1.2
******************************************************************************

 Author: [e-mail]

 purpose:

        Generates selection query strings
 usage:
        query1 = new Query("AND", array("rabbit", "horse", "cow"));
        query2 = new Query("OR",  array("dogs", "cats", "kangaroos"));
        query3 = new Query("NOT", array("sheep"));

        querygen = new QueryGenerator(array(query1, query2, query3));
        query =
           querygen->GetQueryString("animal_table", "mamals_field", "ID_field");

        resultid = mysql_query(query);
        while(row = mysql_fetch_row(resultid))
            echo "got row id ",row["ID_field"],"<br>";

*******************************************************************************/

class QueryGenerator {

    var $m_Querys;
    var $m_start;
    var $m_offset;

    var $m_wordmatch;
    var $m_casematch;

//PUBLIC:

     //  querys   : array of Query objects
     //  wordmatch: only match whole words

    function QueryGenerator($Querys, $wordmatch=false, $casematch=false) {

        $this->m_Querys = $Querys;
        $this->m_wordmatch = $wordmatch;
        $this->m_casematch = $casematch;

        $this->Restrict(0,0);
    }

     // start  : start searching data at this pos
     // offset : number of records to search after pos

    function Restrict($start, $offset) {

        $this->m_start  = $start;
        $this->m_offset = $offset;
    }

    function GetRestrict(&$start, &$offset) {

        $start = $this->m_start;
        $offset = $this->m_offset;
    }

     // table : database table name
     // searchfield: field(s) to search in for resultfield(s)
     // resultfield: field(s) retrieved from search match
     // NOTE: field must be separated by "," eg, "field1,field2"

     // RETURN: function returns resultfield

    function GetQueryString($table, $searchfield, $resultfield= "ID") {

         // begin query string
        $query_string =  "SELECT $resultfield FROM $table WHERE ";

         // get the query string
        $query_string .= $this->BuildQueryString($table, $searchfield);

         // append limit
        if ($this->m_start || $this->m_offset) {
            $query_string .=  "LIMIT $this->m_start";
            if($this->m_offset)
                $query_string .=  ",$this->m_offset";
        }

        return $query_string;
    }

     // build Query string that will return the number of rows selected

    function GetCountQueryString($table, $searchfield) {

         // begin query string
        $query_string =  "SELECT count(*) FROM $table WHERE ";

         // get the query string
        $query_string .= $this->BuildQueryString($table, $searchfield);

        return $query_string;
    }

//PRIVATE:


     // main function that generates the entire query
    function BuildQueryString($table, $searchfield) {

         // parse searchfields
        $searchfields = explode( ",", $searchfield);
        if(!is_array($searchfields))
            $searchfields=array($searchfield);

         // build query for each searchfield
        while ($searchfield = current($searchfields)) {

             // uppercase do case insensitive man
            if (!$this->m_casematch)
                $searchfield =  "UPPER(".$searchfield. ")";

            $firstquery = true;
            $query_string .=  "(";

             // build current query
            reset($this->m_Querys);
            while($query = current($this->m_Querys)) {

                 // append logic
                if ($firstquery)
                    $firstquery=false;
                else if ($query->m_logic ==  "NOT")
                    $query_string.= "AND";
                else
                    $query_string.=$query->m_logic;

                 // append where clause
                $query_string .=
                $this->BuildWhereClause($searchfield, $query);
                next($this->m_Querys);
            }
            $query_string .= ")";
            if (next($searchfields))
                $query_string .=  "OR";
        }
        return $query_string;
    }

     // build where clause
    function BuildWhereClause($searchfield, $query) {

        $query_string.= "(";
        while($word = current($query->m_words)) {

            if (!$this->m_casematch)
                $word = strtoupper($word);

            if ($this->m_wordmatch)
                $search_type =  "REGEXP '[[:<:]]".$word. "[[:>:]]'";
            else
                $search_type =  "REGEXP '$word'";

            if ($query->m_logic ==  "NOT")
                $query_string.= "$searchfield NOT ";
            else
                $query_string.= "$searchfield ";

            $query_string.= $search_type;
            if (next($query->m_words))
                $query_string.= " OR ";
        }
        $query_string.= ")";
        return $query_string;
    }
};
?>