[1] | 1 | <?php |
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| 2 | /** |
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| 3 | * DB.inc.php |
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| 4 | * code by strangecode :: www.strangecode.com :: this document contains copyrighted information |
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| 5 | * |
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| 6 | * DB abstraction layer. |
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| 7 | * |
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| 8 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 9 | * @version 1.0 |
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| 10 | */ |
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| 11 | |
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| 12 | class DB { |
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| 13 | |
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| 14 | // If DB::connect has successfully opened a db connection. |
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| 15 | var $_connected = false; |
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| 16 | |
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| 17 | // Database handler. |
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| 18 | var $dbh; |
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| 19 | |
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| 20 | // Hash of DB parameters. |
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| 21 | var $_params = array(); |
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| 22 | |
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| 23 | // Default parameters. |
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| 24 | var $_param_defaults = array( |
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| 25 | |
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| 26 | // DB passwords should be set as apache environment variables in httpd.conf, readable only by root. |
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| 27 | 'db_server' => 'localhost', |
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| 28 | 'db_name' => null, |
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| 29 | 'db_user' => null, |
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| 30 | 'db_pass' => null, |
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| 31 | |
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| 32 | // Debugging. |
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| 33 | 'db_always_debug' => false, // TRUE = display all SQL queries. |
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| 34 | 'db_debug' => false, // TRUE = display db errors. |
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| 35 | 'db_die_on_failure' => false, // TRUE = script stops on db error. |
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| 36 | ); |
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| 37 | |
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| 38 | // Translate between HTML and MySQL character set names. |
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| 39 | var $mysql_character_sets = array( |
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| 40 | 'utf-8' => 'utf8', |
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| 41 | 'iso-8859-1' => 'latin1', |
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| 42 | ); |
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| 43 | |
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| 44 | // Caches. |
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| 45 | var $existing_tables; |
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| 46 | var $table_columns; |
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| 47 | |
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| 48 | /** |
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| 49 | * This method enforces the singleton pattern for this class. |
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| 50 | * |
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| 51 | * @return object Reference to the global SessionCache object. |
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| 52 | * @access public |
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| 53 | * @static |
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| 54 | */ |
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| 55 | function &getInstance() |
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| 56 | { |
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| 57 | static $instance = null; |
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| 58 | |
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| 59 | if ($instance === null) { |
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| 60 | $instance = new DB(); |
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| 61 | } |
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| 62 | |
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| 63 | return $instance; |
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| 64 | } |
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| 65 | |
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| 66 | /** |
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| 67 | * Constructor. |
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| 68 | */ |
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| 69 | function DB() |
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| 70 | { |
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| 71 | // Initialize default params. |
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| 72 | if (isset($params) && is_array($params)) { |
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| 73 | // Merge new parameters with old overriding only those passed. |
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| 74 | $this->_params = array_merge($this->_params, $params); |
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| 75 | } |
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| 76 | } |
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| 77 | |
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| 78 | /** |
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| 79 | * Set (or overwrite existing) parameters by passing an array of new parameters. |
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| 80 | * |
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| 81 | * @access public |
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| 82 | * |
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| 83 | * @param array $params Array of parameters (key => val pairs). |
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| 84 | */ |
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| 85 | function setParam($params) |
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| 86 | { |
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[8] | 87 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 88 | $this =& DB::getInstance(); |
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| 89 | } |
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| 90 | |
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| 91 | if (isset($params) && is_array($params)) { |
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| 92 | // Merge new parameters with old overriding only those passed. |
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| 93 | $this->_params = array_merge($this->_params, $params); |
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| 94 | } else { |
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| 95 | App::logMsg(sprintf('Parameters are not an array: %s', $params), LOG_ERR, __FILE__, __LINE__); |
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| 96 | } |
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| 97 | } |
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| 98 | |
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| 99 | /** |
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| 100 | * Return the value of a parameter. |
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| 101 | * |
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| 102 | * @access public |
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| 103 | * |
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| 104 | * @param string $param The key of the parameter to return. |
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| 105 | * |
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| 106 | * @return mixed Parameter value. |
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| 107 | */ |
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| 108 | function getParam($param) |
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| 109 | { |
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[8] | 110 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 111 | $this =& DB::getInstance(); |
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| 112 | } |
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| 113 | |
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| 114 | if (isset($this->_params[$param])) { |
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| 115 | return $this->_params[$param]; |
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| 116 | } else { |
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| 117 | App::logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__); |
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| 118 | return null; |
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| 119 | } |
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| 120 | } |
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| 121 | |
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| 122 | /** |
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| 123 | * Connect to database with credentials in params. |
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| 124 | * |
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| 125 | * @access public |
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| 126 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 127 | * @since 28 Aug 2005 14:02:49 |
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| 128 | */ |
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| 129 | function connect() |
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| 130 | { |
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[8] | 131 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 132 | $this =& DB::getInstance(); |
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| 133 | } |
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| 134 | |
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| 135 | if (!$this->getParam('db_name') || !$this->getParam('db_user') || !$this->getParam('db_pass')) { |
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| 136 | App::logMsg('Database credentials missing.', LOG_EMERG, __FILE__, __LINE__); |
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| 137 | return false; |
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| 138 | } |
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| 139 | |
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| 140 | // Connect to database. Always create a new link to the server. |
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| 141 | if ($this->dbh = mysql_connect($this->getParam('db_server'), $this->getParam('db_user'), $this->getParam('db_pass'), true)) { |
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| 142 | // Select database |
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| 143 | mysql_select_db($this->getParam('db_name'), $this->dbh); |
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| 144 | } |
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| 145 | |
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| 146 | // Connection errors. |
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| 147 | if (!$this->dbh || mysql_error($this->dbh)) { |
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| 148 | $mysql_error_msg = $this->dbh ? 'Codebase MySQL error: (' . mysql_errno($this->dbh) . ') ' . mysql_error($this->dbh) : 'Codebase MySQL error: Could not connect to server.'; |
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| 149 | if ($this->getParam('db_debug')) { |
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| 150 | echo $mysql_error_msg . "\n"; |
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| 151 | } else { |
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| 152 | echo _("This page is temporarily unavailable. It should be back up in a few minutes."); |
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| 153 | } |
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| 154 | App::logMsg($mysql_error_msg, LOG_EMERG, __FILE__, __LINE__); |
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| 155 | echo "\n\n<!-- Script execution stopped out of embarrassment. -->"; |
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| 156 | die; |
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| 157 | } |
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| 158 | |
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| 159 | // DB connection success! |
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| 160 | $this->_connected = true; |
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| 161 | |
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[10] | 162 | // Tell MySQL what character set we're useing. Available only on MySQL verions > 4.01.01. |
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| 163 | $this->query("/*!40101 SET NAMES '" . $this->mysql_character_sets[strtolower(App::getParam('character_set'))] . "' */"); |
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| 164 | |
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[1] | 165 | return true; |
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| 166 | } |
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| 167 | |
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| 168 | /** |
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| 169 | * Close db connection. |
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| 170 | * |
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| 171 | * @access public |
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| 172 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 173 | * @since 28 Aug 2005 14:32:01 |
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| 174 | */ |
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| 175 | function close() |
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| 176 | { |
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[8] | 177 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 178 | $this =& DB::getInstance(); |
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| 179 | } |
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| 180 | |
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| 181 | if (!$this->_connected) { |
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| 182 | return false; |
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| 183 | } |
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| 184 | |
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| 185 | mysql_close($this->dbh); |
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| 186 | } |
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| 187 | |
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| 188 | /** |
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| 189 | * Return the current database handler. |
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| 190 | * |
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| 191 | * @access public |
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| 192 | * @return resource Current value of $this->dbh. |
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| 193 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 194 | * @since 20 Aug 2005 13:50:36 |
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| 195 | */ |
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| 196 | function getDBH() |
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| 197 | { |
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[8] | 198 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 199 | $this =& DB::getInstance(); |
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| 200 | } |
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| 201 | |
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| 202 | if (!$this->_connected) { |
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| 203 | return false; |
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| 204 | } |
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| 205 | |
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| 206 | return $this->dbh; |
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| 207 | } |
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| 208 | |
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| 209 | /** |
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| 210 | * Returns connection status |
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| 211 | * |
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| 212 | * @access public |
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| 213 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 214 | * @since 28 Aug 2005 14:58:09 |
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| 215 | */ |
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| 216 | function isConnected() |
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| 217 | { |
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| 218 | return $this->_connected; |
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| 219 | } |
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| 220 | |
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| 221 | /** |
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| 222 | * A wrapper for mysql_query. Allows us to set the database link_identifier, |
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| 223 | * to trap errors and ease debugging. |
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| 224 | * |
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| 225 | * @param string $query The SQL query to execute |
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| 226 | * @param bool $debug If true, prints debugging info |
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| 227 | * @return resource Query identifier |
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| 228 | */ |
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| 229 | function query($query, $debug=false) |
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| 230 | { |
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| 231 | static $_query_count = 0; |
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| 232 | |
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[8] | 233 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 234 | $this =& DB::getInstance(); |
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| 235 | } |
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| 236 | |
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| 237 | if (!$this->_connected) { |
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| 238 | return false; |
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| 239 | } |
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| 240 | |
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| 241 | $_query_count++; |
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| 242 | $debugqry = preg_replace("/\n[\t ]+/", "\n", $query); |
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| 243 | if ($this->getParam('db_always_debug') || $debug) { |
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| 244 | echo "<!-- ----------------- Query $_query_count ---------------------\n$debugqry\n-->\n"; |
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| 245 | } |
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| 246 | |
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| 247 | // Execute! |
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| 248 | $qid = mysql_query($query, $this->dbh); |
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| 249 | |
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| 250 | // Error checking. |
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| 251 | if (!$qid || mysql_error($this->dbh)) { |
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| 252 | if ($this->getParam('db_debug')) { |
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| 253 | echo '<pre style="padding:2em; background:#ddd; font:9px monaco;">' . wordwrap(mysql_error($this->dbh)) . '<hr>' . htmlspecialchars($debugqry) . '</pre>'; |
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| 254 | } else { |
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| 255 | echo _("This page is temporarily unavailable. It should be back up in a few minutes."); |
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| 256 | } |
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| 257 | App::logMsg(sprintf('MySQL error %s: %s in query: %s', mysql_errno($this->dbh), mysql_error($this->dbh), $debugqry), LOG_EMERG, __FILE__, __LINE__); |
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| 258 | if ($this->getParam('db_die_on_failure')) { |
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| 259 | echo "\n\n<!-- Script execution stopped out of embarrassment. -->"; |
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| 260 | die; |
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| 261 | } |
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| 262 | } |
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| 263 | |
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| 264 | return $qid; |
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| 265 | } |
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| 266 | |
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| 267 | /** |
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| 268 | * Loads a list of tables in the current database into an array, and returns |
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| 269 | * true if the requested table is found. Use this function to enable/disable |
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| 270 | * funtionality based upon the current available db tables or to dynamically |
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| 271 | * create tables if missing. |
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| 272 | * |
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| 273 | * @param string $table The name of the table to search. |
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| 274 | * @param bool $strict Get fresh table info (in case DB changed). |
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| 275 | * @return bool true if given $table exists. |
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| 276 | */ |
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| 277 | function tableExists($table, $use_cached_results=true) |
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| 278 | { |
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[8] | 279 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 280 | $this =& DB::getInstance(); |
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| 281 | } |
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| 282 | |
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| 283 | if (!$this->_connected) { |
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| 284 | return false; |
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| 285 | } |
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| 286 | |
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| 287 | if (!isset($this->existing_tables) || !$use_cached_results) { |
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| 288 | $this->existing_tables = array(); |
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| 289 | $qid = $this->query("SHOW TABLES"); |
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| 290 | while (list($row) = mysql_fetch_row($qid)) { |
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| 291 | $this->existing_tables[] = $row; |
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| 292 | } |
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| 293 | } |
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| 294 | if (in_array($table, $this->existing_tables)) { |
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| 295 | return true; |
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| 296 | } else { |
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| 297 | App::logMsg(sprintf('nonexistent DB table: %s.%s', $this->getParam('db_name'), $table), LOG_ALERT, __FILE__, __LINE__); |
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| 298 | return false; |
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| 299 | } |
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| 300 | } |
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| 301 | |
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| 302 | /** |
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| 303 | * Tests if the given array of columns exists in the specified table. |
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| 304 | * |
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| 305 | * @param string $table The name of the table to search. |
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| 306 | * @param array $columns An array of column names. |
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| 307 | * @param bool $strict Exact schema match, or are additional fields in the table okay? |
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| 308 | * @param bool $strict Get fresh table info (in case DB changed). |
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| 309 | * @return bool true if given $table exists. |
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| 310 | */ |
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| 311 | function columnExists($table, $columns, $strict=true, $use_cached_results=true) |
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| 312 | { |
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[8] | 313 | if (!isset($this) || !is_a($this, 'DB')) { |
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[1] | 314 | $this =& DB::getInstance(); |
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| 315 | } |
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| 316 | |
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| 317 | if (!$this->_connected) { |
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| 318 | return false; |
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| 319 | } |
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| 320 | |
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| 321 | // Ensure the table exists. |
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| 322 | if (!$this->tableExists($table, $use_cached_results)) { |
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| 323 | return false; |
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| 324 | } |
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| 325 | |
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| 326 | // For single-value columns. |
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| 327 | if (!is_array($columns)) { |
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| 328 | $columns = array($columns); |
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| 329 | } |
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| 330 | |
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| 331 | if (!isset($this->table_columns[$table]) || !$use_cached_results) { |
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| 332 | // Populate and cache array of current columns for this table. |
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| 333 | $this->table_columns[$table] = array(); |
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| 334 | $qid = $this->query("DESCRIBE $table"); |
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| 335 | while ($row = mysql_fetch_row($qid)) { |
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| 336 | $this->table_columns[$table][] = $row[0]; |
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| 337 | } |
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| 338 | } |
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| 339 | |
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| 340 | if ($strict) { |
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| 341 | // Do an exact comparison of table schemas. |
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| 342 | sort($columns); |
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| 343 | sort($this->table_columns[$table]); |
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| 344 | return $this->table_columns[$table] == $columns; |
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| 345 | } else { |
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| 346 | // Only check that the specified columns are available in the table. |
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| 347 | $match_columns = array_intersect($this->table_columns[$table], $columns); |
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| 348 | sort($columns); |
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| 349 | sort($match_columns); |
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| 350 | return $match_columns == $columns; |
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| 351 | } |
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| 352 | } |
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| 353 | |
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| 354 | /** |
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| 355 | * Reset cached items. |
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| 356 | * |
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| 357 | * @access public |
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| 358 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 359 | * @since 28 Aug 2005 22:10:50 |
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| 360 | */ |
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| 361 | function resetCache() |
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| 362 | { |
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| 363 | $this->existing_tables = null; |
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| 364 | $this->table_columns = null; |
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| 365 | } |
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| 366 | |
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| 367 | } // End. |
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| 368 | |
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| 369 | ?> |
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