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<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
/**
* Contains the DB_QueryTool_EasyJoin class
*
* PHP versions 4 and 5
*
* LICENSE: This source file is subject to version 3.0 of the PHP license
* that is available through the world-wide-web at the following URI:
* http://www.php.net/license/3_0.txt. If you did not receive a copy of
* the PHP License and are unable to obtain it through the web, please
* send a note to license@php.net so we can mail you a copy immediately.
*
* @category Database
* @package DB_QueryTool
* @author Wolfram Kriesing <wk@visionp.de>
* @author Paolo Panto <wk@visionp.de>
* @copyright 2003-2005 Wolfram Kriesing, Paolo Panto
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @version CVS: $Id: EasyJoin.php,v 1.1 2006-12-14 15:04:29 jp_milcent Exp $
* @link http://pear.php.net/package/DB_QueryTool
*/
/**
* require the DB_QueryTool_Query class
*/
require_once 'DB/QueryTool/Query.php';
/**
* DB_QueryTool_EasyJoin class
*
* @category Database
* @package DB_QueryTool
* @author Wolfram Kriesing <wk@visionp.de>
* @copyright 2003-2005 Wolfram Kriesing
* @license http://www.php.net/license/3_0.txt PHP License 3.0
* @link http://pear.php.net/package/DB_QueryTool
*/
class DB_QueryTool_EasyJoin extends DB_QueryTool_Query
{
// {{{ class vars
/**
* This is the regular expression that shall be used to find a table's shortName
* in a column name, the string found by using this regular expression will be removed
* from the column name and it will be checked if it is a table name
* i.e. the default '/_id$/' would find the table name 'user' from the column name 'user_id'
*
* @var string regexp
*/
var $_tableNamePreg = '/_id$/';
/**
* This is to find the column name that is referred by it, so the default find
* from 'user_id' the column 'id' which will be used to refer to the 'user' table
*
* @var string regexp
*/
var $_columnNamePreg = '/^.*_/';
// }}}
// {{{ __construct()
/**
* call parent constructor
* @param mixed $dsn DSN string, DSN array or DB object
* @param array $options
*/
function __construct($dsn=false, $options=array())
{
parent::DB_QueryTool_Query($dsn, $options);
}
// }}}
// {{{ autoJoin()
/**
* Join the given tables, using the column names, to find out how to join the tables;
* i.e., if table1 has a column named "table2_id", this method will join
* "WHERE table1.table2_id=table2.id".
* All joins made here are only concatenated via AND.
* @param array $tables
*/
function autoJoin($tables)
{
// FIXXME if $tables is empty autoJoin all available tables that have a relation
// to $this->table, starting to search in $this->table
settype($tables, 'array');
// add this->table to the tables array, so we go thru the current table first
$tables = array_merge(array($this->table), $tables);
$shortNameIndexed = $this->getTableSpec(true, $tables);
$nameIndexed = $this->getTableSpec(false, $tables);
//print_r($shortNameIndexed);
//print_r($tables); print '<br><br>';
if (sizeof($shortNameIndexed) != sizeof($tables)) {
$this->_errorLog("autoJoin-ERROR: not all the tables are in the tableSpec!<br />");
}
$joinTables = array();
$joinConditions = array();
foreach ($tables as $aTable) { // go through $this->table and all the given tables
if ($metadata = $this->metadata($aTable))
foreach ($metadata as $aCol => $x) { // go through each row to check which might be related to $aTable
$possibleTableShortName = preg_replace($this->_tableNamePreg, '' , $aCol);
$possibleColumnName = preg_replace($this->_columnNamePreg, '' , $aCol);
//print "$aTable.$aCol .... possibleTableShortName=$possibleTableShortName .... possibleColumnName=$possibleColumnName<br />";
if (isset($shortNameIndexed[$possibleTableShortName])) {
// are the tables given in the tableSpec?
if (!$shortNameIndexed[$possibleTableShortName]['name'] ||
!$nameIndexed[$aTable]['name']) {
// its an error of the developer, so log the error, dont show it to the end user
$this->_errorLog("autoJoin-ERROR: '$aTable' is not given in the tableSpec!<br />");
} else {
// do only join different table.col combination,
// we should not join stuff like 'question.question=question.question'
// this would be quite stupid, but it used to be :-(
if ($shortNameIndexed[$possibleTableShortName]['name'] != $aTable ||
$possibleColumnName != $aCol
) {
$where = $shortNameIndexed[$possibleTableShortName]['name'].".$possibleColumnName=$aTable.$aCol";
$this->addJoin($nameIndexed[$aTable]['name'], $where);
$this->addJoin($shortNameIndexed[$possibleTableShortName]['name'], $where);
}
}
}
}
}
}
// }}}
}
?>