* @link http://www.yiiframework.com/ * @copyright 2008-2013 Yii Software LLC * @license http://www.yiiframework.com/license/ */ /** * CDbConnection represents a connection to a database. * * CDbConnection works together with {@link CDbCommand}, {@link CDbDataReader} * and {@link CDbTransaction} to provide data access to various DBMS * in a common set of APIs. They are a thin wrapper of the {@link http://www.php.net/manual/en/ref.pdo.php PDO} * PHP extension. * * To establish a connection, set {@link setActive active} to true after * specifying {@link connectionString}, {@link username} and {@link password}. * * The following example shows how to create a CDbConnection instance and establish * the actual connection: *
 * $connection=new CDbConnection($dsn,$username,$password);
 * $connection->active=true;
 * 
* * After the DB connection is established, one can execute an SQL statement like the following: *
 * $command=$connection->createCommand($sqlStatement);
 * $command->execute();   // a non-query SQL statement execution
 * // or execute an SQL query and fetch the result set
 * $reader=$command->query();
 *
 * // each $row is an array representing a row of data
 * foreach($reader as $row) ...
 * 
* * One can do prepared SQL execution and bind parameters to the prepared SQL: *
 * $command=$connection->createCommand($sqlStatement);
 * $command->bindParam($name1,$value1);
 * $command->bindParam($name2,$value2);
 * $command->execute();
 * 
* * To use transaction, do like the following: *
 * $transaction=$connection->beginTransaction();
 * try
 * {
 *    $connection->createCommand($sql1)->execute();
 *    $connection->createCommand($sql2)->execute();
 *    //.... other SQL executions
 *    $transaction->commit();
 * }
 * catch(Exception $e)
 * {
 *    $transaction->rollback();
 * }
 * 
* * CDbConnection also provides a set of methods to support setting and querying * of certain DBMS attributes, such as {@link getNullConversion nullConversion}. * * Since CDbConnection implements the interface IApplicationComponent, it can * be used as an application component and be configured in application configuration, * like the following, *
 * array(
 *     'components'=>array(
 *         'db'=>array(
 *             'class'=>'CDbConnection',
 *             'connectionString'=>'sqlite:path/to/dbfile',
 *         ),
 *     ),
 * )
 * 
* * Use the {@link driverName} property if you want to force the DB connection to use a particular driver * by the given name, disregarding of what was set in the {@link connectionString} property. This might * be useful when working with ODBC connections. Sample code: * *
 * 'db'=>array(
 *     'class'=>'CDbConnection',
 *     'driverName'=>'mysql',
 *     'connectionString'=>'odbc:Driver={MySQL};Server=127.0.0.1;Database=test',
 *     'username'=>'',
 *     'password'=>'',
 * ),
 * 
* * @property boolean $active Whether the DB connection is established. * @property PDO $pdoInstance The PDO instance, null if the connection is not established yet. * @property CDbTransaction $currentTransaction The currently active transaction. Null if no active transaction. * @property CDbSchema $schema The database schema for the current connection. * @property CDbCommandBuilder $commandBuilder The command builder. * @property string $lastInsertID The row ID of the last row inserted, or the last value retrieved from the sequence object. * @property mixed $columnCase The case of the column names. * @property mixed $nullConversion How the null and empty strings are converted. * @property boolean $autoCommit Whether creating or updating a DB record will be automatically committed. * @property boolean $persistent Whether the connection is persistent or not. * @property string $driverName Name of the DB driver. This property is read-write since 1.1.16. * Before 1.1.15 it was read-only. * @property string $clientVersion The version information of the DB driver. * @property string $connectionStatus The status of the connection. * @property boolean $prefetch Whether the connection performs data prefetching. * @property string $serverInfo The information of DBMS server. * @property string $serverVersion The version information of DBMS server. * @property integer $timeout Timeout settings for the connection. * @property array $attributes Attributes (name=>value) that are previously explicitly set for the DB connection. * @property array $stats The first element indicates the number of SQL statements executed, * and the second element the total time spent in SQL execution. * * @author Qiang Xue * @package system.db * @since 1.0 */ class CDbConnection extends CApplicationComponent { /** * @var string The Data Source Name, or DSN, contains the information required to connect to the database. * @see http://www.php.net/manual/en/function.PDO-construct.php * * Note that if you're using GBK or BIG5 then it's highly recommended to * update to PHP 5.3.6+ and to specify charset via DSN like * 'mysql:dbname=mydatabase;host=127.0.0.1;charset=GBK;'. */ public $connectionString; /** * @var string the username for establishing DB connection. Defaults to empty string. */ public $username=''; /** * @var string the password for establishing DB connection. Defaults to empty string. */ public $password=''; /** * @var integer number of seconds that table metadata can remain valid in cache. * Use 0 or negative value to indicate not caching schema. * If greater than 0 and the primary cache is enabled, the table metadata will be cached. * @see schemaCachingExclude */ public $schemaCachingDuration=0; /** * @var array list of tables whose metadata should NOT be cached. Defaults to empty array. * @see schemaCachingDuration */ public $schemaCachingExclude=array(); /** * @var string the ID of the cache application component that is used to cache the table metadata. * Defaults to 'cache' which refers to the primary cache application component. * Set this property to false if you want to disable caching table metadata. */ public $schemaCacheID='cache'; /** * @var integer number of seconds that query results can remain valid in cache. * Use 0 or negative value to indicate not caching query results (the default behavior). * * In order to enable query caching, this property must be a positive * integer and {@link queryCacheID} must point to a valid cache component ID. * * The method {@link cache()} is provided as a convenient way of setting this property * and {@link queryCachingDependency} on the fly. * * @see cache * @see queryCachingDependency * @see queryCacheID * @since 1.1.7 */ public $queryCachingDuration=0; /** * @var CCacheDependency|ICacheDependency the dependency that will be used when saving query results into cache. * @see queryCachingDuration * @since 1.1.7 */ public $queryCachingDependency; /** * @var integer the number of SQL statements that need to be cached next. * If this is 0, then even if query caching is enabled, no query will be cached. * Note that each time after executing a SQL statement (whether executed on DB server or fetched from * query cache), this property will be reduced by 1 until 0. * @since 1.1.7 */ public $queryCachingCount=0; /** * @var string the ID of the cache application component that is used for query caching. * Defaults to 'cache' which refers to the primary cache application component. * Set this property to false if you want to disable query caching. * @since 1.1.7 */ public $queryCacheID='cache'; /** * @var boolean whether the database connection should be automatically established * the component is being initialized. Defaults to true. Note, this property is only * effective when the CDbConnection object is used as an application component. */ public $autoConnect=true; /** * @var string the charset used for database connection. The property is only used * for MySQL, MariaDB and PostgreSQL databases. Defaults to null, meaning using default charset * as specified by the database. * * Note that if you're using GBK or BIG5 then it's highly recommended to * update to PHP 5.3.6+ and to specify charset via DSN like * 'mysql:dbname=mydatabase;host=127.0.0.1;charset=GBK;'. */ public $charset; /** * @var boolean whether to turn on prepare emulation. Defaults to false, meaning PDO * will use the native prepare support if available. For some databases (such as MySQL), * this may need to be set true so that PDO can emulate the prepare support to bypass * the buggy native prepare support. Note, this property is only effective for PHP 5.1.3 or above. * The default value is null, which will not change the ATTR_EMULATE_PREPARES value of PDO. */ public $emulatePrepare; /** * @var boolean whether to log the values that are bound to a prepare SQL statement. * Defaults to false. During development, you may consider setting this property to true * so that parameter values bound to SQL statements are logged for debugging purpose. * You should be aware that logging parameter values could be expensive and have significant * impact on the performance of your application. */ public $enableParamLogging=false; /** * @var boolean whether to enable profiling the SQL statements being executed. * Defaults to false. This should be mainly enabled and used during development * to find out the bottleneck of SQL executions. */ public $enableProfiling=false; /** * @var string the default prefix for table names. Defaults to null, meaning no table prefix. * By setting this property, any token like '{{tableName}}' in {@link CDbCommand::text} will * be replaced by 'prefixTableName', where 'prefix' refers to this property value. * @since 1.1.0 */ public $tablePrefix; /** * @var array list of SQL statements that should be executed right after the DB connection is established. * @since 1.1.1 */ public $initSQLs; /** * @var array mapping between PDO driver and schema class name. * A schema class can be specified using path alias. * @since 1.1.6 */ public $driverMap=array( 'cubrid'=>'CCubridSchema', // CUBRID 'pgsql'=>'CPgsqlSchema', // PostgreSQL 'mysqli'=>'CMysqlSchema', // MySQL 'mysql'=>'CMysqlSchema', // MySQL,MariaDB 'sqlite'=>'CSqliteSchema', // sqlite 3 'sqlite2'=>'CSqliteSchema', // sqlite 2 'mssql'=>'CMssqlSchema', // Mssql driver on windows hosts 'dblib'=>'CMssqlSchema', // dblib drivers on linux (and maybe others os) hosts 'sqlsrv'=>'CMssqlSchema', // Mssql 'oci'=>'COciSchema', // Oracle driver ); /** * @var string Custom PDO wrapper class. * @since 1.1.8 */ public $pdoClass = 'PDO'; private $_driverName; private $_attributes=array(); private $_active=false; private $_pdo; private $_transaction; private $_schema; /** * Constructor. * Note, the DB connection is not established when this connection * instance is created. Set {@link setActive active} property to true * to establish the connection. * @param string $dsn The Data Source Name, or DSN, contains the information required to connect to the database. * @param string $username The user name for the DSN string. * @param string $password The password for the DSN string. * @see http://www.php.net/manual/en/function.PDO-construct.php */ public function __construct($dsn='',$username='',$password='') { $this->connectionString=$dsn; $this->username=$username; $this->password=$password; $this->charset='utf8'; } /** * Close the connection when serializing. * @return array */ public function __sleep() { $this->close(); return array_keys(get_object_vars($this)); } /** * Returns a list of available PDO drivers. * @return array list of available PDO drivers * @see http://www.php.net/manual/en/function.PDO-getAvailableDrivers.php */ public static function getAvailableDrivers() { return PDO::getAvailableDrivers(); } /** * Initializes the component. * This method is required by {@link IApplicationComponent} and is invoked by application * when the CDbConnection is used as an application component. * If you override this method, make sure to call the parent implementation * so that the component can be marked as initialized. */ public function init() { parent::init(); if($this->autoConnect) $this->setActive(true); } /** * Returns whether the DB connection is established. * @return boolean whether the DB connection is established */ public function getActive() { return $this->_active; } /** * Open or close the DB connection. * @param boolean $value whether to open or close DB connection * @throws CException if connection fails */ public function setActive($value) { if($value!=$this->_active) { if($value) $this->open(); else $this->close(); } } /** * Sets the parameters about query caching. * This method can be used to enable or disable query caching. * By setting the $duration parameter to be 0, the query caching will be disabled. * Otherwise, query results of the new SQL statements executed next will be saved in cache * and remain valid for the specified duration. * If the same query is executed again, the result may be fetched from cache directly * without actually executing the SQL statement. * @param integer $duration the number of seconds that query results may remain valid in cache. * If this is 0, the caching will be disabled. * @param CCacheDependency|ICacheDependency $dependency the dependency that will be used when saving * the query results into cache. * @param integer $queryCount number of SQL queries that need to be cached after calling this method. Defaults to 1, * meaning that the next SQL query will be cached. * @return static the connection instance itself. * @since 1.1.7 */ public function cache($duration, $dependency=null, $queryCount=1) { $this->queryCachingDuration=$duration; $this->queryCachingDependency=$dependency; $this->queryCachingCount=$queryCount; return $this; } /** * Opens DB connection if it is currently not * @throws CException if connection fails */ protected function open() { if($this->_pdo===null) { if(empty($this->connectionString)) throw new CDbException('CDbConnection.connectionString cannot be empty.'); try { Yii::trace('Opening DB connection','system.db.CDbConnection'); $this->_pdo=$this->createPdoInstance(); $this->initConnection($this->_pdo); $this->_active=true; } catch(PDOException $e) { if(YII_DEBUG) { throw new CDbException('CDbConnection failed to open the DB connection: '. $e->getMessage(),(int)$e->getCode(),$e->errorInfo); } else { Yii::log($e->getMessage(),CLogger::LEVEL_ERROR,'exception.CDbException'); throw new CDbException('CDbConnection failed to open the DB connection.',(int)$e->getCode(),$e->errorInfo); } } } } /** * Closes the currently active DB connection. * It does nothing if the connection is already closed. */ public function close() { Yii::trace('Closing DB connection','system.db.CDbConnection'); $this->_pdo=null; $this->_active=false; $this->_schema=null; } /** * Creates the PDO instance. * When some functionalities are missing in the pdo driver, we may use * an adapter class to provide them. * @throws CDbException when failed to open DB connection * @return PDO the pdo instance */ protected function createPdoInstance() { $pdoClass=$this->pdoClass; if(($driver=$this->getDriverName())!==null) { if($driver==='mssql' || $driver==='dblib') $pdoClass='CMssqlPdoAdapter'; elseif($driver==='sqlsrv') $pdoClass='CMssqlSqlsrvPdoAdapter'; } if(!class_exists($pdoClass)) throw new CDbException(Yii::t('yii','CDbConnection is unable to find PDO class "{className}". Make sure PDO is installed correctly.', array('{className}'=>$pdoClass))); @$instance=new $pdoClass($this->connectionString,$this->username,$this->password,$this->_attributes); if(!$instance) throw new CDbException(Yii::t('yii','CDbConnection failed to open the DB connection.')); return $instance; } /** * Initializes the open db connection. * This method is invoked right after the db connection is established. * The default implementation is to set the charset for MySQL, MariaDB and PostgreSQL database connections. * @param PDO $pdo the PDO instance */ protected function initConnection($pdo) { $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION); if($this->emulatePrepare!==null && constant('PDO::ATTR_EMULATE_PREPARES')) $pdo->setAttribute(PDO::ATTR_EMULATE_PREPARES,$this->emulatePrepare); if($this->charset!==null) { $driver=strtolower($pdo->getAttribute(PDO::ATTR_DRIVER_NAME)); if(in_array($driver,array('pgsql','mysql','mysqli'))) $pdo->exec('SET NAMES '.$pdo->quote($this->charset)); } if($this->initSQLs!==null) { foreach($this->initSQLs as $sql) $pdo->exec($sql); } } /** * Returns the PDO instance. * @return PDO the PDO instance, null if the connection is not established yet */ public function getPdoInstance() { return $this->_pdo; } /** * Creates a command for execution. * @param mixed $query the DB query to be executed. This can be either a string representing a SQL statement, * or an array representing different fragments of a SQL statement. Please refer to {@link CDbCommand::__construct} * for more details about how to pass an array as the query. If this parameter is not given, * you will have to call query builder methods of {@link CDbCommand} to build the DB query. * @return CDbCommand the DB command */ public function createCommand($query=null) { $this->setActive(true); return new CDbCommand($this,$query); } /** * Returns the currently active transaction. * @return CDbTransaction the currently active transaction. Null if no active transaction. */ public function getCurrentTransaction() { if($this->_transaction!==null) { if($this->_transaction->getActive()) return $this->_transaction; } return null; } /** * Starts a transaction. * @return CDbTransaction the transaction initiated */ public function beginTransaction() { Yii::trace('Starting transaction','system.db.CDbConnection'); $this->setActive(true); $this->_pdo->beginTransaction(); return $this->_transaction=new CDbTransaction($this); } /** * Returns the database schema for the current connection * @throws CDbException if CDbConnection does not support reading schema for specified database driver * @return CDbSchema the database schema for the current connection */ public function getSchema() { if($this->_schema!==null) return $this->_schema; else { $driver=$this->getDriverName(); if(isset($this->driverMap[$driver])) return $this->_schema=Yii::createComponent($this->driverMap[$driver], $this); else throw new CDbException(Yii::t('yii','CDbConnection does not support reading schema for {driver} database.', array('{driver}'=>$driver))); } } /** * Returns the SQL command builder for the current DB connection. * @return CDbCommandBuilder the command builder */ public function getCommandBuilder() { return $this->getSchema()->getCommandBuilder(); } /** * Returns the ID of the last inserted row or sequence value. * @param string $sequenceName name of the sequence object (required by some DBMS) * @return string the row ID of the last row inserted, or the last value retrieved from the sequence object * @see http://www.php.net/manual/en/function.PDO-lastInsertId.php */ public function getLastInsertID($sequenceName='') { $this->setActive(true); return $this->_pdo->lastInsertId($sequenceName); } /** * Quotes a string value for use in a query. * @param string $str string to be quoted * @return string the properly quoted string * @see http://www.php.net/manual/en/function.PDO-quote.php */ public function quoteValue($str) { if(is_int($str) || is_float($str)) return $str; $this->setActive(true); if(($value=$this->_pdo->quote($str))!==false) return $value; else // the driver doesn't support quote (e.g. oci) return "'" . addcslashes(str_replace("'", "''", $str), "\000\n\r\\\032") . "'"; } /** * Quotes a table name for use in a query. * If the table name contains schema prefix, the prefix will also be properly quoted. * @param string $name table name * @return string the properly quoted table name */ public function quoteTableName($name) { return $this->getSchema()->quoteTableName($name); } /** * Quotes a column name for use in a query. * If the column name contains prefix, the prefix will also be properly quoted. * @param string $name column name * @return string the properly quoted column name */ public function quoteColumnName($name) { return $this->getSchema()->quoteColumnName($name); } /** * Determines the PDO type for the specified PHP type. * @param string $type The PHP type (obtained by gettype() call). * @return integer the corresponding PDO type */ public function getPdoType($type) { static $map=array ( 'boolean'=>PDO::PARAM_BOOL, 'integer'=>PDO::PARAM_INT, 'string'=>PDO::PARAM_STR, 'resource'=>PDO::PARAM_LOB, 'NULL'=>PDO::PARAM_NULL, ); return isset($map[$type]) ? $map[$type] : PDO::PARAM_STR; } /** * Returns the case of the column names * @return mixed the case of the column names * @see http://www.php.net/manual/en/pdo.setattribute.php */ public function getColumnCase() { return $this->getAttribute(PDO::ATTR_CASE); } /** * Sets the case of the column names. * @param mixed $value the case of the column names * @see http://www.php.net/manual/en/pdo.setattribute.php */ public function setColumnCase($value) { $this->setAttribute(PDO::ATTR_CASE,$value); } /** * Returns how the null and empty strings are converted. * @return mixed how the null and empty strings are converted * @see http://www.php.net/manual/en/pdo.setattribute.php */ public function getNullConversion() { return $this->getAttribute(PDO::ATTR_ORACLE_NULLS); } /** * Sets how the null and empty strings are converted. * @param mixed $value how the null and empty strings are converted * @see http://www.php.net/manual/en/pdo.setattribute.php */ public function setNullConversion($value) { $this->setAttribute(PDO::ATTR_ORACLE_NULLS,$value); } /** * Returns whether creating or updating a DB record will be automatically committed. * Some DBMS (such as sqlite) may not support this feature. * @return boolean whether creating or updating a DB record will be automatically committed. */ public function getAutoCommit() { return $this->getAttribute(PDO::ATTR_AUTOCOMMIT); } /** * Sets whether creating or updating a DB record will be automatically committed. * Some DBMS (such as sqlite) may not support this feature. * @param boolean $value whether creating or updating a DB record will be automatically committed. */ public function setAutoCommit($value) { $this->setAttribute(PDO::ATTR_AUTOCOMMIT,$value); } /** * Returns whether the connection is persistent or not. * Some DBMS (such as sqlite) may not support this feature. * @return boolean whether the connection is persistent or not */ public function getPersistent() { return $this->getAttribute(PDO::ATTR_PERSISTENT); } /** * Sets whether the connection is persistent or not. * Some DBMS (such as sqlite) may not support this feature. * @param boolean $value whether the connection is persistent or not */ public function setPersistent($value) { return $this->setAttribute(PDO::ATTR_PERSISTENT,$value); } /** * Returns the name of the DB driver. * @return string name of the DB driver. */ public function getDriverName() { if($this->_driverName!==null) return $this->_driverName; elseif(($pos=strpos($this->connectionString,':'))!==false) return $this->_driverName=strtolower(substr($this->connectionString,0,$pos)); //return $this->getAttribute(PDO::ATTR_DRIVER_NAME); } /** * Changes the name of the DB driver. Overrides value extracted from the {@link connectionString}, * which is behavior by default. * @param string $driverName to be set. Valid values are the keys from the {@link driverMap} property. * @see getDriverName * @see driverName * @since 1.1.16 */ public function setDriverName($driverName) { $this->_driverName=strtolower($driverName); } /** * Returns the version information of the DB driver. * @return string the version information of the DB driver */ public function getClientVersion() { return $this->getAttribute(PDO::ATTR_CLIENT_VERSION); } /** * Returns the status of the connection. * Some DBMS (such as sqlite) may not support this feature. * @return string the status of the connection */ public function getConnectionStatus() { return $this->getAttribute(PDO::ATTR_CONNECTION_STATUS); } /** * Returns whether the connection performs data prefetching. * @return boolean whether the connection performs data prefetching */ public function getPrefetch() { return $this->getAttribute(PDO::ATTR_PREFETCH); } /** * Returns the information of DBMS server. * @return string the information of DBMS server */ public function getServerInfo() { return $this->getAttribute(PDO::ATTR_SERVER_INFO); } /** * Returns the version information of DBMS server. * @return string the version information of DBMS server */ public function getServerVersion() { return $this->getAttribute(PDO::ATTR_SERVER_VERSION); } /** * Returns the timeout settings for the connection. * @return integer timeout settings for the connection */ public function getTimeout() { return $this->getAttribute(PDO::ATTR_TIMEOUT); } /** * Obtains a specific DB connection attribute information. * @param integer $name the attribute to be queried * @return mixed the corresponding attribute information * @see http://www.php.net/manual/en/function.PDO-getAttribute.php */ public function getAttribute($name) { $this->setActive(true); return $this->_pdo->getAttribute($name); } /** * Sets an attribute on the database connection. * @param integer $name the attribute to be set * @param mixed $value the attribute value * @see http://www.php.net/manual/en/function.PDO-setAttribute.php */ public function setAttribute($name,$value) { if($this->_pdo instanceof PDO) $this->_pdo->setAttribute($name,$value); else $this->_attributes[$name]=$value; } /** * Returns the attributes that are previously explicitly set for the DB connection. * @return array attributes (name=>value) that are previously explicitly set for the DB connection. * @see setAttributes * @since 1.1.7 */ public function getAttributes() { return $this->_attributes; } /** * Sets a set of attributes on the database connection. * @param array $values attributes (name=>value) to be set. * @see setAttribute * @since 1.1.7 */ public function setAttributes($values) { foreach($values as $name=>$value) $this->_attributes[$name]=$value; } /** * Returns the statistical results of SQL executions. * The results returned include the number of SQL statements executed and * the total time spent. * In order to use this method, {@link enableProfiling} has to be set true. * @return array the first element indicates the number of SQL statements executed, * and the second element the total time spent in SQL execution. */ public function getStats() { $logger=Yii::getLogger(); $timings=$logger->getProfilingResults(null,'system.db.CDbCommand.query'); $count=count($timings); $time=array_sum($timings); $timings=$logger->getProfilingResults(null,'system.db.CDbCommand.execute'); $count+=count($timings); $time+=array_sum($timings); return array($count,$time); } }