[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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[15] | 9 | * @version 1.0.1 |
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[1] | 10 | */ |
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[42] | 11 | |
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[1] | 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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[42] | 37 | |
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[1] | 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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[42] | 43 | |
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[1] | 44 | // Caches. |
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| 45 | var $existing_tables; |
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| 46 | var $table_columns; |
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[42] | 47 | |
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[1] | 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 $instance; |
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| 64 | } |
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[42] | 65 | |
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[1] | 66 | /** |
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| 67 | * Constructor. |
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| 68 | */ |
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| 69 | function DB() |
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| 70 | { |
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| 71 | // Initialize default params. |
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| 72 | if (isset($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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[157] | 87 | $_this =& DB::getInstance(); |
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[1] | 88 | |
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| 89 | if (isset($params) && is_array($params)) { |
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| 90 | // Merge new parameters with old overriding only those passed. |
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[157] | 91 | $_this->_params = array_merge($_this->_params, $params); |
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[1] | 92 | } else { |
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| 93 | App::logMsg(sprintf('Parameters are not an array: %s', $params), LOG_ERR, __FILE__, __LINE__); |
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| 94 | } |
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| 95 | } |
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| 96 | |
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| 97 | /** |
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| 98 | * Return the value of a parameter. |
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| 99 | * |
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| 100 | * @access public |
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| 101 | * |
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| 102 | * @param string $param The key of the parameter to return. |
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| 103 | * |
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| 104 | * @return mixed Parameter value. |
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| 105 | */ |
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| 106 | function getParam($param) |
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| 107 | { |
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[157] | 108 | $_this =& DB::getInstance(); |
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[1] | 109 | |
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[157] | 110 | if (isset($_this->_params[$param])) { |
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| 111 | return $_this->_params[$param]; |
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[1] | 112 | } else { |
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| 113 | App::logMsg(sprintf('Parameter is not set: %s', $param), LOG_DEBUG, __FILE__, __LINE__); |
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| 114 | return null; |
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| 115 | } |
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| 116 | } |
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[42] | 117 | |
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[1] | 118 | /** |
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| 119 | * Connect to database with credentials in params. |
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| 120 | * |
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| 121 | * @access public |
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| 122 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 123 | * @since 28 Aug 2005 14:02:49 |
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| 124 | */ |
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| 125 | function connect() |
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| 126 | { |
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[157] | 127 | $_this =& DB::getInstance(); |
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[42] | 128 | |
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[157] | 129 | if (!$_this->getParam('db_name') || !$_this->getParam('db_user') || !$_this->getParam('db_pass')) { |
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[1] | 130 | App::logMsg('Database credentials missing.', LOG_EMERG, __FILE__, __LINE__); |
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| 131 | return false; |
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| 132 | } |
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[42] | 133 | |
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[1] | 134 | // Connect to database. Always create a new link to the server. |
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[157] | 135 | if ($_this->dbh = mysql_connect($_this->getParam('db_server'), $_this->getParam('db_user'), $_this->getParam('db_pass'), true)) { |
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[1] | 136 | // Select database |
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[157] | 137 | mysql_select_db($_this->getParam('db_name'), $_this->dbh); |
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[1] | 138 | } |
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[42] | 139 | |
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[15] | 140 | // Test for connection errors. |
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[157] | 141 | if (!$_this->dbh || mysql_error($_this->dbh)) { |
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| 142 | $mysql_error_msg = $_this->dbh ? 'Codebase MySQL error: (' . mysql_errno($_this->dbh) . ') ' . mysql_error($_this->dbh) : 'Codebase MySQL error: Could not connect to server.'; |
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[15] | 143 | App::logMsg($mysql_error_msg, LOG_EMERG, __FILE__, __LINE__); |
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| 144 | |
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| 145 | // Print helpful or pretty error? |
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[157] | 146 | if ($_this->getParam('db_debug')) { |
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[1] | 147 | echo $mysql_error_msg . "\n"; |
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| 148 | } else { |
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| 149 | echo _("This page is temporarily unavailable. It should be back up in a few minutes."); |
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| 150 | } |
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[15] | 151 | |
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| 152 | // Die or continue without connection? |
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[157] | 153 | if ($_this->getParam('db_die_on_failure')) { |
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[15] | 154 | echo "\n\n<!-- Script execution stopped out of embarrassment. -->"; |
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| 155 | die; |
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| 156 | } else { |
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| 157 | return false; |
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| 158 | } |
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[1] | 159 | } |
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[42] | 160 | |
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[1] | 161 | // DB connection success! |
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[157] | 162 | $_this->_connected = true; |
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[1] | 163 | |
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[10] | 164 | // Tell MySQL what character set we're useing. Available only on MySQL verions > 4.01.01. |
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[157] | 165 | $_this->query("/*!40101 SET NAMES '" . $_this->mysql_character_sets[strtolower(App::getParam('character_set'))] . "' */"); |
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[10] | 166 | |
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[1] | 167 | return true; |
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| 168 | } |
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[42] | 169 | |
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[1] | 170 | /** |
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| 171 | * Close db connection. |
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| 172 | * |
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| 173 | * @access public |
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| 174 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 175 | * @since 28 Aug 2005 14:32:01 |
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| 176 | */ |
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| 177 | function close() |
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| 178 | { |
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[157] | 179 | $_this =& DB::getInstance(); |
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[42] | 180 | |
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[157] | 181 | if (!$_this->_connected) { |
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[1] | 182 | return false; |
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| 183 | } |
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| 184 | |
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[157] | 185 | mysql_close($_this->dbh); |
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[1] | 186 | } |
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[42] | 187 | |
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[1] | 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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[157] | 192 | * @return resource Current value of $_this->dbh. |
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[1] | 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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[157] | 198 | $_this =& DB::getInstance(); |
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[42] | 199 | |
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[157] | 200 | if (!$_this->_connected) { |
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[1] | 201 | return false; |
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| 202 | } |
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| 203 | |
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[157] | 204 | return $_this->dbh; |
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[1] | 205 | } |
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[42] | 206 | |
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[1] | 207 | /** |
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| 208 | * Returns connection status |
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| 209 | * |
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| 210 | * @access public |
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| 211 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 212 | * @since 28 Aug 2005 14:58:09 |
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| 213 | */ |
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| 214 | function isConnected() |
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| 215 | { |
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[157] | 216 | $_this =& DB::getInstance(); |
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| 217 | |
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| 218 | return $_this->_connected; |
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[1] | 219 | } |
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[71] | 220 | |
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| 221 | /** |
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| 222 | * Returns a properly escaped string using mysql_real_escape_string() with the current connection's charset. |
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| 223 | * |
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| 224 | * @access public |
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| 225 | * @param string $string Input string to be sent as SQL query. |
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| 226 | * @return string Escaped string from mysql_real_escape_string() |
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| 227 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 228 | * @since 06 Mar 2006 16:41:32 |
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| 229 | */ |
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| 230 | function escapeString($string) |
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| 231 | { |
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[157] | 232 | $_this =& DB::getInstance(); |
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| 233 | |
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| 234 | return mysql_real_escape_string($string, $_this->dbh); |
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[71] | 235 | } |
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[42] | 236 | |
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[1] | 237 | /** |
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| 238 | * A wrapper for mysql_query. Allows us to set the database link_identifier, |
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| 239 | * to trap errors and ease debugging. |
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| 240 | * |
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| 241 | * @param string $query The SQL query to execute |
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| 242 | * @param bool $debug If true, prints debugging info |
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| 243 | * @return resource Query identifier |
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| 244 | */ |
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| 245 | function query($query, $debug=false) |
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| 246 | { |
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| 247 | static $_query_count = 0; |
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[42] | 248 | |
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[157] | 249 | $_this =& DB::getInstance(); |
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[42] | 250 | |
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[157] | 251 | if (!$_this->_connected) { |
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[1] | 252 | return false; |
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| 253 | } |
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| 254 | |
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| 255 | $_query_count++; |
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| 256 | $debugqry = preg_replace("/\n[\t ]+/", "\n", $query); |
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[157] | 257 | if ($_this->getParam('db_always_debug') || $debug) { |
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[1] | 258 | echo "<!-- ----------------- Query $_query_count ---------------------\n$debugqry\n-->\n"; |
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| 259 | } |
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[42] | 260 | |
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[1] | 261 | // Execute! |
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[157] | 262 | $qid = mysql_query($query, $_this->dbh); |
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[42] | 263 | |
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[1] | 264 | // Error checking. |
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[157] | 265 | if (!$qid || mysql_error($_this->dbh)) { |
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| 266 | if ($_this->getParam('db_debug')) { |
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| 267 | echo '<pre style="padding:2em; background:#ddd; font:9px monaco;">' . wordwrap(mysql_error($_this->dbh)) . '<hr>' . htmlspecialchars($debugqry) . '</pre>'; |
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[1] | 268 | } else { |
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| 269 | echo _("This page is temporarily unavailable. It should be back up in a few minutes."); |
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| 270 | } |
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[157] | 271 | App::logMsg(sprintf('MySQL error %s: %s in query: %s', mysql_errno($_this->dbh), mysql_error($_this->dbh), $debugqry), LOG_EMERG, __FILE__, __LINE__); |
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| 272 | if ($_this->getParam('db_die_on_failure')) { |
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[1] | 273 | echo "\n\n<!-- Script execution stopped out of embarrassment. -->"; |
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| 274 | die; |
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| 275 | } |
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| 276 | } |
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[42] | 277 | |
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[1] | 278 | return $qid; |
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| 279 | } |
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| 280 | |
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| 281 | /** |
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[42] | 282 | * Loads a list of tables in the current database into an array, and returns |
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[1] | 283 | * true if the requested table is found. Use this function to enable/disable |
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[42] | 284 | * funtionality based upon the current available db tables or to dynamically |
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[1] | 285 | * create tables if missing. |
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| 286 | * |
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| 287 | * @param string $table The name of the table to search. |
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| 288 | * @param bool $strict Get fresh table info (in case DB changed). |
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| 289 | * @return bool true if given $table exists. |
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| 290 | */ |
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| 291 | function tableExists($table, $use_cached_results=true) |
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[42] | 292 | { |
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[157] | 293 | $_this =& DB::getInstance(); |
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[42] | 294 | |
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[157] | 295 | if (!$_this->_connected) { |
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[1] | 296 | return false; |
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| 297 | } |
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| 298 | |
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[157] | 299 | if (!isset($_this->existing_tables) || !$use_cached_results) { |
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| 300 | $_this->existing_tables = array(); |
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| 301 | $qid = $_this->query("SHOW TABLES"); |
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[1] | 302 | while (list($row) = mysql_fetch_row($qid)) { |
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[157] | 303 | $_this->existing_tables[] = $row; |
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[1] | 304 | } |
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| 305 | } |
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[157] | 306 | if (in_array($table, $_this->existing_tables)) { |
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[1] | 307 | return true; |
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| 308 | } else { |
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[157] | 309 | App::logMsg(sprintf('nonexistent DB table: %s.%s', $_this->getParam('db_name'), $table), LOG_ALERT, __FILE__, __LINE__); |
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[1] | 310 | return false; |
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| 311 | } |
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| 312 | } |
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[42] | 313 | |
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[1] | 314 | /** |
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| 315 | * Tests if the given array of columns exists in the specified table. |
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| 316 | * |
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| 317 | * @param string $table The name of the table to search. |
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| 318 | * @param array $columns An array of column names. |
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| 319 | * @param bool $strict Exact schema match, or are additional fields in the table okay? |
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| 320 | * @param bool $strict Get fresh table info (in case DB changed). |
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| 321 | * @return bool true if given $table exists. |
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| 322 | */ |
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| 323 | function columnExists($table, $columns, $strict=true, $use_cached_results=true) |
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[42] | 324 | { |
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[157] | 325 | $_this =& DB::getInstance(); |
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[42] | 326 | |
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[157] | 327 | if (!$_this->_connected) { |
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[1] | 328 | return false; |
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| 329 | } |
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| 330 | |
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| 331 | // Ensure the table exists. |
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[157] | 332 | if (!$_this->tableExists($table, $use_cached_results)) { |
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[1] | 333 | return false; |
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| 334 | } |
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[42] | 335 | |
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[1] | 336 | // For single-value columns. |
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| 337 | if (!is_array($columns)) { |
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| 338 | $columns = array($columns); |
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| 339 | } |
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[42] | 340 | |
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[157] | 341 | if (!isset($_this->table_columns[$table]) || !$use_cached_results) { |
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[1] | 342 | // Populate and cache array of current columns for this table. |
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[157] | 343 | $_this->table_columns[$table] = array(); |
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| 344 | $qid = $_this->query("DESCRIBE $table"); |
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[1] | 345 | while ($row = mysql_fetch_row($qid)) { |
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[157] | 346 | $_this->table_columns[$table][] = $row[0]; |
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[1] | 347 | } |
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| 348 | } |
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[42] | 349 | |
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[1] | 350 | if ($strict) { |
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| 351 | // Do an exact comparison of table schemas. |
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| 352 | sort($columns); |
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[157] | 353 | sort($_this->table_columns[$table]); |
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| 354 | return $_this->table_columns[$table] == $columns; |
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[1] | 355 | } else { |
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| 356 | // Only check that the specified columns are available in the table. |
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[157] | 357 | $match_columns = array_intersect($_this->table_columns[$table], $columns); |
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[1] | 358 | sort($columns); |
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| 359 | sort($match_columns); |
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| 360 | return $match_columns == $columns; |
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| 361 | } |
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| 362 | } |
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[42] | 363 | |
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[1] | 364 | /** |
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| 365 | * Reset cached items. |
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| 366 | * |
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| 367 | * @access public |
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| 368 | * @author Quinn Comendant <quinn@strangecode.com> |
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| 369 | * @since 28 Aug 2005 22:10:50 |
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| 370 | */ |
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| 371 | function resetCache() |
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| 372 | { |
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[157] | 373 | $_this->existing_tables = null; |
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| 374 | $_this->table_columns = null; |
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[1] | 375 | } |
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[42] | 376 | |
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[1] | 377 | } // End. |
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| 378 | |
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| 379 | ?> |
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