/yii/framework/db/CDbConnection.php
PHP | 794 lines | 457 code | 24 blank | 313 comment | 23 complexity | 7ea8c2716a24abc425287067f1e2186a MD5 | raw file
- <?php
- /**
- * CDbConnection class file
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @link http://www.yiiframework.com/
- * @copyright Copyright © 2008-2011 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:
- * <pre>
- * $connection=new CDbConnection($dsn,$username,$password);
- * $connection->active=true;
- * </pre>
- *
- * After the DB connection is established, one can execute an SQL statement like the following:
- * <pre>
- * $command=$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) ...
- * </pre>
- *
- * One can do prepared SQL execution and bind parameters to the prepared SQL:
- * <pre>
- * $command=$connection->createCommand($sqlStatement);
- * $command->bindParam($name1,$value1);
- * $command->bindParam($name2,$value2);
- * $command->execute();
- * </pre>
- *
- * To use transaction, do like the following:
- * <pre>
- * $transaction=$connection->beginTransaction();
- * try
- * {
- * $connection->createCommand($sql1)->execute();
- * $connection->createCommand($sql2)->execute();
- * //.... other SQL executions
- * $transaction->commit();
- * }
- * catch(Exception $e)
- * {
- * $transaction->rollBack();
- * }
- * </pre>
- *
- * 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,
- * <pre>
- * array(
- * 'components'=>array(
- * 'db'=>array(
- * 'class'=>'CDbConnection',
- * 'connectionString'=>'sqlite:path/to/dbfile',
- * ),
- * ),
- * )
- * </pre>
- *
- * @author Qiang Xue <qiang.xue@gmail.com>
- * @version $Id: CDbConnection.php 3255 2011-06-13 12:39:41Z alexander.makarow $
- * @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.
- * @since 1.0.10
- */
- 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 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 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.
- * @since 1.0.5
- */
- 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.
- * @since 1.0.6
- */
- 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(
- 'pgsql'=>'CPgsqlSchema', // PostgreSQL
- 'mysqli'=>'CMysqlSchema', // MySQL
- 'mysql'=>'CMysqlSchema', // MySQL
- '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 $_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;
- }
- /**
- * 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 $dependency the dependency that will be used when saving the query results into cache.
- * @param integer $queryCount number of SQL queries that need to be cached after calling this method. Defaults to 1,
- * meaning that the next SQL query will be cached.
- * @return CDbConnection the connection instance itself.
- * @since 1.1.7
- */
- public function cache($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(Yii::t('yii','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 $e)
- {
- if(YII_DEBUG)
- {
- throw new CDbException(Yii::t('yii','CDbConnection failed to open the DB connection: {error}',
- array('{error}'=>$e->getMessage())),(int)$e->getCode(),$e->errorInfo);
- }
- else
- {
- Yii::log($e->getMessage(),CLogger::LEVEL_ERROR,'exception.CDbException');
- throw new CDbException(Yii::t('yii','CDbConnection failed to open the DB connection.'),(int)$e->getCode(),$e->errorInfo);
- }
- }
- }
- }
- /**
- * Closes the currently active DB connection.
- * It does nothing if the connection is already closed.
- */
- protected 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 provides them.
- * @return PDO the pdo instance
- * @since 1.0.4
- */
- protected function createPdoInstance()
- {
- $pdoClass=$this->pdoClass;
- if(($pos=strpos($this->connectionString,':'))!==false)
- {
- $driver=strtolower(substr($this->connectionString,0,$pos));
- if($driver==='mssql' || $driver==='dblib' || $driver==='sqlsrv')
- $pdoClass='CMssqlPdoAdapter';
- }
- return new $pdoClass($this->connectionString,$this->username,
- $this->password,$this->_attributes);
- }
- /**
- * 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 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
- * @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
- * @since 1.0.4
- */
- 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 $map=array
- (
- 'boolean'=>PDO::PARAM_BOOL,
- 'integer'=>PDO::PARAM_INT,
- 'string'=>PDO::PARAM_STR,
- 'NULL'=>PDO::PARAM_NULL,
- );
- return isset($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(($pos=strpos($this->connectionString, ':'))!==false)
- return strtolower(substr($this->connectionString, 0, $pos));
- // return $this->getAttribute(PDO::ATTR_DRIVER_NAME);
- }
- /**
- * 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.
- * @since 1.0.6
- */
- 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);
- }
- }