1<?php
2/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4: */
3
4/**
5 * Contains the DB_QueryTool_EasyJoin class
6 *
7 * PHP versions 4 and 5
8 *
9 * LICENSE: Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE FREEBSD PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY
23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 *
30 * @category  Database
31 * @package   DB_QueryTool
32 * @author    Wolfram Kriesing <wk@visionp.de>
33 * @author    Paolo Panto <wk@visionp.de>
34 * @copyright 2003-2007 Wolfram Kriesing, Paolo Panto
35 * @license   http://www.debian.org/misc/bsd.license  BSD License (3 Clause)
36 * @version   CVS: $Id: EasyJoin.php,v 1.11 2007/11/16 20:33:49 quipo Exp $
37 * @link      http://pear.php.net/package/DB_QueryTool
38 */
39
40/**
41 * require the DB_QueryTool_Query class
42 */
43require_once 'DB/QueryTool/Query.php';
44
45/**
46 * DB_QueryTool_EasyJoin class
47 *
48 * @category  Database
49 * @package   DB_QueryTool
50 * @author    Wolfram Kriesing <wk@visionp.de>
51 * @copyright 2003-2007 Wolfram Kriesing
52 * @license   http://www.debian.org/misc/bsd.license  BSD License (3 Clause)
53 * @link      http://pear.php.net/package/DB_QueryTool
54 */
55class DB_QueryTool_EasyJoin extends DB_QueryTool_Query
56{
57    // {{{ class vars
58
59    /**
60     * This is the regular expression that shall be used to find a table's shortName
61     * in a column name, the string found by using this regular expression will be removed
62     * from the column name and it will be checked if it is a table name
63     * i.e. the default '/_id$/' would find the table name 'user' from the column name 'user_id'
64     *
65     * @var string regexp
66     */
67    var $_tableNamePreg = '/_id$/';
68
69    /**
70     * This is to find the column name that is referred by it, so the default find
71     * from 'user_id' the column 'id' which will be used to refer to the 'user' table
72     *
73     * @var string regexp
74     */
75    var $_columnNamePreg = '/^.*_/';
76
77    // }}}
78    // {{{ __construct()
79
80    /**
81     * call parent constructor
82     *
83     * @param mixed $dsn     DSN string, DSN array or DB object
84     * @param array $options database options
85     */
86    function __construct($dsn = false, $options = array())
87    {
88        parent::DB_QueryTool_Query($dsn, $options);
89    }
90
91    // }}}
92    // {{{ autoJoin()
93
94    /**
95     * Join the given tables, using the column names, to find out how to join the tables;
96     * i.e., if table1 has a column named &quot;table2_id&quot;, this method will join
97     * &quot;WHERE table1.table2_id=table2.id&quot;.
98     * All joins made here are only concatenated via AND.
99     *
100     * @param array $tables tables to join
101     *
102     * @return void
103     */
104    function autoJoin($tables)
105    {
106        // FIXXME if $tables is empty autoJoin all available tables that have a relation
107        // to $this->table, starting to search in $this->table
108        settype($tables, 'array');
109        // add this->table to the tables array, so we go thru the current table first
110        $tables = array_merge(array($this->table), $tables);
111
112        $shortNameIndexed = $this->getTableSpec(true, $tables);
113        $nameIndexed      = $this->getTableSpec(false, $tables);
114
115        //print_r($shortNameIndexed);
116        //print_r($tables);        print '<br><br>';
117        if (sizeof($shortNameIndexed) != sizeof($tables)) {
118            $this->_errorLog("autoJoin-ERROR: not all the tables are in the tableSpec!<br />");
119        }
120
121        $joinTables     = array();
122        $joinConditions = array();
123        foreach ($tables as $aTable) {   // go through $this->table and all the given tables
124            if ($metadata = $this->metadata($aTable))
125            foreach ($metadata as $aCol => $x) {   // go through each row to check which might be related to $aTable
126                $possibleTableShortName = preg_replace($this->_tableNamePreg, '', $aCol);
127                $possibleColumnName     = preg_replace($this->_columnNamePreg, '', $aCol);
128                //print "$aTable.$aCol .... possibleTableShortName=$possibleTableShortName .... possibleColumnName=$possibleColumnName<br />";
129                if (isset($shortNameIndexed[$possibleTableShortName])) {
130                    // are the tables given in the tableSpec?
131                    if (!$shortNameIndexed[$possibleTableShortName]['name'] ||
132                        !$nameIndexed[$aTable]['name']) {
133                        // its an error of the developer, so log the error, dont show it to the end user
134                        $this->_errorLog("autoJoin-ERROR: '$aTable' is not given in the tableSpec!<br />");
135                    } else {
136                        // do only join different table.col combination,
137                        // we should not join stuff like 'question.question=question.question'
138                        // this would be quite stupid, but it used to be :-(
139                        if ($shortNameIndexed[$possibleTableShortName]['name'] != $aTable ||
140                            $possibleColumnName != $aCol
141                        ) {
142                            $where = $shortNameIndexed[$possibleTableShortName]['name'].".$possibleColumnName=$aTable.$aCol";
143                            $this->addJoin($nameIndexed[$aTable]['name'], $where);
144                            $this->addJoin($shortNameIndexed[$possibleTableShortName]['name'], $where);
145                        }
146                    }
147                }
148            }
149        }
150    }
151
152    // }}}
153}
154?>