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File: Mysql.php

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  Classes of Dmitry Koterov  >  DbSimple  >  Mysql.php  >  Download  
File: Mysql.php
Role: Class source
Content type: text/plain
Description: Mysql driver
Class: DbSimple
Abstraction to access several SQL databases
Author: By
Last change:
Date: 8 years ago
Size: 6,759 bytes
 

Contents

Class file image Download
<?php
/**
 * DbSimple_Mysql: MySQL database.
 * (C) 2005 Dmitry Koterov, http://forum.dklab.ru/users/DmitryKoterov/
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * See http://www.gnu.org/copyleft/lesser.html
 *
 * Placeholders end blobs are emulated.
 *
 * @version 2.x $Id: Mysql.php 59 2006-12-17 21:16:54Z dk $
 */
require_once dirname(__FILE__) . '/Generic.php';


/**
 * Database class for MySQL.
 */
class DbSimple_Mysql extends DbSimple_Generic_Database
{
    var
$link;

   
/**
     * constructor(string $dsn)
     * Connect to MySQL.
     */
   
function DbSimple_Mysql($dsn)
    {
       
$p = DbSimple_Generic::parseDSN($dsn);
        if (!
is_callable('mysql_connect')) {
            return
$this->_setLastError("-1", "MySQL extension is not loaded", "mysql_connect");
        }
       
$ok = $this->link = @mysql_connect(
           
$p['host'] . (empty($p['port'])? "" : ":".$p['port']),
           
$p['user'],
           
$p['pass'],
           
true
       
);
       
$this->_resetLastError();
        if (!
$ok) return $this->_setDbError('mysql_connect()');
       
$ok = @mysql_select_db(preg_replace('{^/}s', '', $p['path']), $this->link);
        if (!
$ok) return $this->_setDbError('mysql_select_db()');
    }


    function
_performEscape($s, $isIdent=false)
    {
        if (!
$isIdent) {
            return
"'" . mysql_real_escape_string($s, $this->link) . "'";
        } else {
            return
"`" . str_replace('`', '``', $s) . "`";
        }
    }


    function
_performTransaction($parameters=null)
    {
        return
$this->query('BEGIN');
    }


    function&
_performNewBlob($blobid=null)
    {
       
$obj =& new DbSimple_Mysql_Blob($this, $blobid);
        return
$obj;
    }


    function
_performGetBlobFieldNames($result)
    {
       
$blobFields = array();
        for (
$i=mysql_num_fields($result)-1; $i>=0; $i--) {
           
$type = mysql_field_type($result, $i);
            if (
strpos($type, "BLOB") !== false) $blobFields[] = mysql_field_name($result, $i);
        }
        return
$blobFields;
    }


    function
_performGetPlaceholderIgnoreRe()
    {
        return
'
            " (?> [^"\\\\]+|\\\\"|\\\\)* " |
            \' (?> [^\'\\\\]+|\\\\\'|\\\\)* \' |
            ` (?> [^`]+ | ``)* ` | # backticks
            /\* .*? \*/ # comments
        '
;
    }


    function
_performCommit()
    {
        return
$this->query('COMMIT');
    }


    function
_performRollback()
    {
        return
$this->query('ROLLBACK');
    }


    function
_performTransformQuery(&$queryMain, $how)
    {
       
// If we also need to calculate total number of found rows...
       
switch ($how) {
           
// Prepare total calculation (if possible)
           
case 'CALC_TOTAL':
               
$m = null;
                if (
preg_match('/^(\s* SELECT)(.*)/six', $queryMain[0], $m)) {
                    if (
$this->_calcFoundRowsAvailable()) {
                       
$queryMain[0] = $m[1] . ' SQL_CALC_FOUND_ROWS' . $m[2];
                    }
                }
                return
true;
       
           
// Perform total calculation.
           
case 'GET_TOTAL':
               
// Built-in calculation available?
               
if ($this->_calcFoundRowsAvailable()) {
                   
$queryMain = array('SELECT FOUND_ROWS()');
                }
               
// Else use manual calculation.
                // TODO: GROUP BY ... -> COUNT(DISTINCT ...)
               
$re = '/^
                    (?> -- [^\r\n]* | \s+)*
                    (\s* SELECT \s+) #1
                    (.*?) #2
                    (\s+ FROM \s+ .*?) #3
                        ((?:\s+ ORDER \s+ BY \s+ .*?)?) #4
                        ((?:\s+ LIMIT \s+ \S+ \s* (?:, \s* \S+ \s*)? )?) #5
                $/six'
;
               
$m = null;
                if (
preg_match($re, $queryMain[0], $m)) {
                   
$query[0] = $m[1] . $this->_fieldList2Count($m[2]) . " AS C" . $m[3];
                   
$skipTail = substr_count($m[4] . $m[5], '?');
                    if (
$skipTail) array_splice($query, -$skipTail);
                }
                return
true;
        }
       
        return
false;
    }


    function
_performQuery($queryMain)
    {
       
$this->_lastQuery = $queryMain;
       
$this->_expandPlaceholders($queryMain, false);
       
$result = @mysql_query($queryMain[0], $this->link);
        if (
$result === false) return $this->_setDbError($queryMain[0]);
        if (!
is_resource($result)) {
            if (
preg_match('/^\s* INSERT \s+/six', $queryMain[0])) {
               
// INSERT queries return generated ID.
               
return @mysql_insert_id($this->link);
            }
           
// Non-SELECT queries return number of affected rows, SELECT - resource.
           
return @mysql_affected_rows($this->link);
        }
        return
$result;
    }

   
    function
_performFetch($result)
    {
       
$row = @mysql_fetch_assoc($result);
        if (
mysql_error()) return $this->_setDbError($this->_lastQuery);
        if (
$row === false) return null;
        return
$row;
    }
   
   
    function
_setDbError($query)
    {
        return
$this->_setLastError(mysql_errno(), mysql_error(), $query);
    }
   
   
    function
_calcFoundRowsAvailable()
    {
       
$ok = version_compare(mysql_get_server_info($this->link), '4.0') >= 0;
        return
$ok;
    }
}


class
DbSimple_Mysql_Blob extends DbSimple_Generic_Blob
{
   
// MySQL does not support separate BLOB fetching.
   
var $blobdata = null;
    var
$curSeek = 0;

    function
DbSimple_Mysql_Blob(&$database, $blobdata=null)
    {
       
$this->blobdata = $blobdata;
       
$this->curSeek = 0;
    }

    function
read($len)
    {
       
$p = $this->curSeek;
       
$this->curSeek = min($this->curSeek + $len, strlen($this->blobdata));
        return
substr($this->blobdata, $this->curSeek, $len);
    }

    function
write($data)
    {
       
$this->blobdata .= $data;
    }

    function
close()
    {
        return
$this->blobdata;
    }

    function
length()
    {
        return
strlen($this->blobdata);
    }
}
?>