doctrine2/lib/Doctrine/DBAL/Connection.php

<?php
/*
 *  $Id: Connection.php 4933 2008-09-12 10:58:33Z romanb $
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals
 * and is licensed under the LGPL. For more information, see
 * <http://www.doctrine-project.org>.
 */

namespace Doctrine\DBAL;

use Doctrine\Common\EventManager;
use Doctrine\Common\DoctrineException;

/**
 * A wrapper around a Doctrine\DBAL\Driver\Connection that adds features like
 * events, transaction isolation levels, configuration, emulated transaction nesting,
 * lazy connecting and more.
 *
 * @license     http://www.opensource.org/licenses/lgpl-license.php LGPL
 * @since       1.0
 * @version     $Revision: 4933 $
 * @author      Konsta Vesterinen <kvesteri@cc.hut.fi>
 * @author      Lukas Smith <smith@pooteeweet.org> (MDB2 library)
 * @author      Roman Borschel <roman@code-factory.org>
 * @todo
 * 1) REPLICATION SUPPORT
 * Replication support should be tackled at this layer (DBAL).
 * There can be options that look like:
 *       'slaves' => array(
 *           'slave1' => array(
 *                user, pass etc.
 *           ),
 *           'slave2' => array(
 *                user, pass etc.
 *           )),
 *       'slaveConnectionResolver' => new MySlaveConnectionResolver(),
 *       'masters' => array(...),
 *       'masterConnectionResolver' => new MyMasterConnectionResolver()
 *
 * Doctrine\DBAL could ship with a simple standard broker that uses a primitive
 * round-robin approach to distribution. User can provide its own brokers.
 */
class Connection
{
	/**
	 * Constant for transaction isolation level READ UNCOMMITTED.
	 */
	const TRANSACTION_READ_UNCOMMITTED = 1;
	/**
	 * Constant for transaction isolation level READ COMMITTED.
	 */
	const TRANSACTION_READ_COMMITTED = 2;
    /**
     * Constant for transaction isolation level REPEATABLE READ.
     */
    const TRANSACTION_REPEATABLE_READ = 3;
    /**
     * Constant for transaction isolation level SERIALIZABLE.
     */
    const TRANSACTION_SERIALIZABLE = 4;

    /**
     * The wrapped driver connection.
     *
     * @var Doctrine\DBAL\Driver\Connection
     */
    protected $_conn;

    /**
     * The Configuration.
     *
     * @var Doctrine\DBAL\Configuration
     */
    protected $_config;

    /**
     * The EventManager.
     *
     * @var Doctrine\Common\EventManager
     */
    protected $_eventManager;

    /**
     * Whether or not a connection has been established.
     *
     * @var boolean
     */
    protected $_isConnected = false;

    /**
     * The transaction nesting level.
     *
     * @var integer
     */
    protected $_transactionNestingLevel = 0;
    
    /**
     * The currently active transaction isolation level.
     *
     * @var integer
     */
    protected $_transactionIsolationLevel;

    /**
     * The parameters used during creation of the Connection instance.
     *
     * @var array
     */
    protected $_params = array();

    /**
     * The query count. Represents the number of executed database queries by the connection.
     *
     * @var integer
     */
    protected $_queryCount = 0;

    /**
     * The DatabasePlatform object that provides information about the
     * database platform used by the connection.
     *
     * @var Doctrine\DBAL\Platforms\AbstractPlatform
     */
    protected $_platform;

    /**
     * The schema manager.
     *
     * @var Doctrine\DBAL\Schema\SchemaManager
     */
    protected $_schemaManager;

	/**
     * The used DBAL driver.
     *
     * @var Doctrine\DBAL\Driver
     */
    protected $_driver;

    /**
     * Whether to quote identifiers. Read from the configuration upon construction.
     *
     * @var boolean
     */
    protected $_quoteIdentifiers = false;

    /**
     * Initializes a new instance of the Connection class.
     *
     * @param array $params  The connection parameters.
     * @param Driver $driver
     * @param Configuration $config
     * @param EventManager $eventManager
     */
    public function __construct(array $params, Driver $driver, Configuration $config = null,
            EventManager $eventManager = null)
    {
        $this->_driver = $driver;
        $this->_params = $params;

        if (isset($params['pdo'])) {
            $this->_conn = $params['pdo'];
            $this->_isConnected = true;
        }

        // Create default config and event manager if none given
        if ( ! $config) {
            $config = new Configuration();
		}
		if ( ! $eventManager) {
            $eventManager = new EventManager();
		}

		$this->_config = $config;
        $this->_eventManager = $eventManager;
        $this->_platform = $driver->getDatabasePlatform();
        $this->_transactionIsolationLevel = $this->_platform->getDefaultTransactionIsolationLevel();
        $this->_quoteIdentifiers = $config->getQuoteIdentifiers();
        $this->_platform->setQuoteIdentifiers($this->_quoteIdentifiers);
	}

    /**
     * Get the array of parameters used to instantiated this connection instance
     *
     * @return array $params
     */
    public function getParams()
    {
        return $this->_params;
    }

	/**
	 * Get the name of the database connected to for this Connection instance
	 *
	 * @return string $database
	 */
	public function getDatabase()
	{
		return $this->_driver->getDatabase($this);
	}

	/**
	 * Gets the DBAL driver instance.
	 *
	 * @return Doctrine\DBAL\Driver
	 */
	public function getDriver()
	{
		return $this->_driver;
	}

	/**
	 * Gets the Configuration used by the Connection.
	 *
	 * @return Doctrine\DBAL\Configuration
	 */
	public function getConfiguration()
	{
		return $this->_config;
	}

	/**
	 * Gets the EventManager used by the Connection.
	 *
	 * @return Doctrine\Common\EventManager
	 */
	public function getEventManager()
	{
		return $this->_eventManager;
	}

	/**
	 * Gets the DatabasePlatform for the connection.
	 *
	 * @return Doctrine\DBAL\Platforms\AbstractPlatform
	 */
	public function getDatabasePlatform()
	{
		return $this->_platform;
	}

	/**
	 * Establishes the connection with the database.
	 *
	 * @return boolean
	 */
	public function connect()
	{
		if ($this->_isConnected) return false;

		$driverOptions = isset($this->_params['driverOptions']) ?
		$this->_params['driverOptions'] : array();
		$user = isset($this->_params['user']) ?
		$this->_params['user'] : null;
		$password = isset($this->_params['password']) ?
		$this->_params['password'] : null;

		$this->_conn = $this->_driver->connect(
		$this->_params,
		$user,
		$password,
		$driverOptions
		);

		$this->_isConnected = true;

		return true;
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetch(PDO::FETCH_ASSOC).
	 *
	 * @param string $statement The SQL query.
	 * @param array $params The query parameters.
	 * @return array
	 */
	public function fetchRow($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetch(\PDO::FETCH_ASSOC);
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetch(PDO::FETCH_NUM).
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchArray($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetch(\PDO::FETCH_NUM);
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetchAll(PDO::FETCH_COLUMN, ...).
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @param int $colnum               0-indexed column number to retrieve
	 * @return array
	 */
	public function fetchColumn($statement, array $params = array(), $colnum = 0)
	{
		return $this->execute($statement, $params)->fetchAll(\PDO::FETCH_COLUMN, $colnum);
	}

	/**
	 * Whether an actual connection to the database is established.
	 *
	 * @return boolean
	 */
	public function isConnected()
	{
		return $this->_isConnected;
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetchAll(PDO::FETCH_BOTH).
	 *
	 * @param string $statement         sql query to be executed
	 * @param array $params             prepared statement params
	 * @return array
	 */
	public function fetchBoth($statement, array $params = array())
	{
		return $this->execute($statement, $params)->fetchAll(\PDO::FETCH_BOTH);
	}

	/**
	 * Deletes table row(s) matching the specified identifier.
	 *
	 * @param string $table         The table to delete data from
	 * @param array $identifier     An associateve array containing identifier fieldname-value pairs.
	 * @return integer              The number of affected rows
	 */
	public function delete($tableName, array $identifier)
	{
		$this->connect();
		$criteria = array();
		foreach (array_keys($identifier) as $id) {
			$criteria[] = $this->quoteIdentifier($id) . ' = ?';
		}

		$query = 'DELETE FROM '
		. $this->quoteIdentifier($tableName)
		. ' WHERE ' . implode(' AND ', $criteria);

		return $this->exec($query, array_values($identifier));
	}

	/**
	 * Closes the connection.
	 *
	 * @return void
	 */
	public function close()
	{
		unset($this->_conn);
		$this->_isConnected = false;
	}

	/**
	 * Sets the transaction isolation level.
	 *
	 * @param integer $level The level to set.
	 */
	public function setTransactionIsolation($level)
	{
		$this->_transactionIsolationLevel = $level;
		return $this->exec($this->_platform->getSetTransactionIsolationSql($level));
	}

	/**
	 * Gets the currently active transaction isolation level.
	 *
	 * @return integer The current transaction isolation level.
	 */
	public function getTransactionIsolation()
	{
		return $this->_transactionIsolationLevel;
	}

	/**
	 * Updates table row(s) with specified data
	 *
	 * @throws Doctrine\DBAL\ConnectionException    if something went wrong at the database level
	 * @param string $table     The table to insert data into
	 * @param array $values     An associateve array containing column-value pairs.
	 * @return mixed            boolean false if empty value array was given,
	 *                          otherwise returns the number of affected rows
	 */
	public function update($tableName, array $data, array $identifier)
	{
		$this->connect();
		if (empty($data)) {
			return false;
		}

		$set = array();
		foreach ($data as $columnName => $value) {
			$set[] = $this->quoteIdentifier($columnName) . ' = ?';
		}

		$params = array_merge(array_values($data), array_values($identifier));

		$sql  = 'UPDATE ' . $this->quoteIdentifier($tableName)
		. ' SET ' . implode(', ', $set)
		. ' WHERE ' . implode(' = ? AND ', array_keys($identifier))
		. ' = ?';

		return $this->exec($sql, $params);
	}

	/**
	 * Inserts a table row with specified data.
	 *
	 * @param string $table     The table to insert data into.
	 * @param array $fields     An associateve array containing fieldname-value pairs.
	 * @return mixed            boolean false if empty value array was given,
	 *                          otherwise returns the number of affected rows
	 */
	public function insert($tableName, array $data)
	{
		$this->connect();
		if (empty($data)) {
			return false;
		}

		// column names are specified as array keys
		$cols = array();
		$a = array();
		foreach ($data as $columnName => $value) {
			$cols[] = $this->quoteIdentifier($columnName);
			$a[] = '?';
		}

		$query = 'INSERT INTO ' . $this->quoteIdentifier($tableName)
		. ' (' . implode(', ', $cols) . ') '
		. 'VALUES (';
		$query .= implode(', ', $a) . ')';

		return $this->exec($query, array_values($data));
	}

	/**
	 * Set the charset on the current connection
	 *
	 * @param string    charset
	 */
	public function setCharset($charset)
	{
		$this->exec($this->_platform->getSetCharsetSql($charset));
	}

	/**
	 * Quote a string so it can be safely used as a table or column name, even if
	 * it is a reserved name.
	 *
	 * Delimiting style depends on the underlying database platform that is being used.
	 *
	 * NOTE: Just because you CAN use delimited identifiers doesn't mean
	 * you SHOULD use them.  In general, they end up causing way more
	 * problems than they solve.
	 *
	 * @param string $str           identifier name to be quoted
	 * @param bool $checkOption     check the 'quote_identifier' option
	 *
	 * @return string               quoted identifier string
	 */
	public function quoteIdentifier($str)
	{
		if ($this->_quoteIdentifiers) {
			return $this->_platform->quoteIdentifier($str);
		}
		return $str;
	}

	/**
	 * Quotes a given input parameter.
	 *
	 * @param mixed $input  Parameter to be quoted.
	 * @param string $type  Type of the parameter.
	 * @return string  The quoted parameter.
	 */
	public function quote($input, $type = null)
	{
		$this->connect();
		return $this->_conn->quote($input, $type);
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetchAll(PDO::FETCH_ASSOC).
	 *
	 * @param string $sql The SQL query.
	 * @param array $params The query parameters.
	 * @return array
	 */
	public function fetchAll($sql, array $params = array())
	{
		return $this->execute($sql, $params)->fetchAll(\PDO::FETCH_ASSOC);
	}

	/**
	 * Convenience method for PDO::query("...") followed by $stmt->fetchColumn().
	 *
	 * @param string $statement The SQL query.
	 * @param array $params The query parameters.
	 * @param int $colnum 0-indexed column number to retrieve
	 * @return mixed
	 */
	public function fetchOne($statement, array $params = array(), $colnum = 0)
	{
		return $this->execute($statement, $params)->fetchColumn($colnum);
	}

	/**
	 * Prepares an SQL statement.
	 *
	 * @param string $statement
	 * @return Statement
	 */
	public function prepare($statement)
	{
		$this->connect();
		return $this->_conn->prepare($statement);
	}

	/**
	 * Queries the database with limit and offset added to the query and returns
	 * a Statement object.
	 *
	 * @param string $query
	 * @param integer $limit
	 * @param integer $offset
	 * @return Statement
	 */
	public function select($query, $limit = 0, $offset = 0)
	{
		if ($limit > 0 || $offset > 0) {
			$query = $this->_platform->modifyLimitQuery($query, $limit, $offset);
		}
		return $this->execute($query);
	}

	/**
	 * Executes an SQL SELECT query with the given parameters.
	 *
	 * @param string $query     sql query
	 * @param array $params     query parameters
	 *
	 * @return PDOStatement
	 */
	public function execute($query, array $params = array())
	{
		$this->connect();

		if ($this->_config->getSqlLogger()) {
			$this->_config->getSqlLogger()->logSql($query, $params);
		}

		if ( ! empty($params)) {
			$stmt = $this->prepare($query);
			$stmt->execute($params);
			return $stmt;
		} else {
			$stmt = $this->_conn->query($query);
			$this->_queryCount++;
			return $stmt;
		}
	}

	/**
	 * Executes an SQL INSERT/UPDATE/DELETE query with the given parameters.
	 *
	 * @param string $query     sql query
	 * @param array $params     query parameters
	 *
	 * @return PDOStatement
	 * @todo Rename to executeUpdate().
	 */
	public function exec($query, array $params = array()) {
		$this->connect();

		if ($this->_config->getSqlLogger()) {
			$this->_config->getSqlLogger()->logSql($query, $params);
		}

		if ( ! empty($params)) {
			$stmt = $this->prepare($query);
			$stmt->execute($params);
			return $stmt->rowCount();
		} else {
			$count = $this->_conn->exec($query);
			$this->_queryCount++;
			return $count;
		}
	}

	/**
	 * Returns the number of queries executed by the connection.
	 *
	 * @return integer
	 */
	public function getQueryCount()
	{
		return $this->_queryCount;
	}

	/**
	 * Returns the current transaction nesting level.
	 *
	 * @return integer  The nesting level. A value of 0 means theres no active transaction.
	 */
	public function getTransactionNestingLevel()
	{
		return $this->_transactionNestingLevel;
	}

	/**
	 * Fetch the SQLSTATE associated with the last operation on the database handle
	 *
	 * @return integer
	 */
	public function errorCode()
	{
		$this->connect();
		return $this->_conn->errorCode();
	}

	/**
	 * Fetch extended error information associated with the last operation on the database handle
	 *
	 * @return array
	 */
	public function errorInfo()
	{
		$this->connect();
		return $this->_conn->errorInfo();
	}

	/**
	 * Returns the ID of the last inserted row, or the last value from a sequence object,
	 * depending on the underlying driver.
	 *
	 * Note: This method may not return a meaningful or consistent result across different drivers,
	 * because the underlying database may not even support the notion of auto-increment fields or sequences.
	 *
	 * @param string $table     Name of the table into which a new row was inserted.
	 * @param string $field     Name of the field into which a new row was inserted.
	 */
	public function lastInsertId($seqName = null)
	{
		$this->connect();
		return $this->_conn->lastInsertId($seqName);
	}

	/**
	 * Start a transaction or set a savepoint.
	 *
	 * if trying to set a savepoint and there is no active transaction
	 * a new transaction is being started.
	 *
	 * @return boolean
	 */
	public function beginTransaction()
	{
		$this->connect();
		if ($this->_transactionNestingLevel == 0) {
			$this->_conn->beginTransaction();
		}
		++$this->_transactionNestingLevel;
		return true;
	}

	/**
	 * Commits the database changes done during a transaction that is in
	 * progress or release a savepoint. This function may only be called when
	 * auto-committing is disabled, otherwise it will fail.
	 *
	 * @return boolean FALSE if commit couldn't be performed, TRUE otherwise
	 */
	public function commit()
	{
		if ($this->_transactionNestingLevel == 0) {
			throw ConnectionException::commitFailedNoActiveTransaction();
		}

		$this->connect();

		if ($this->_transactionNestingLevel == 1) {
			$this->_conn->commit();
		}
        --$this->_transactionNestingLevel;

        return true;
    }

    /**
     * Cancel any database changes done during a transaction or since a specific
     * savepoint that is in progress. This function may only be called when
     * auto-committing is disabled, otherwise it will fail. Therefore, a new
     * transaction is implicitly started after canceling the pending changes.
     *
     * this method can be listened with onPreTransactionRollback and onTransactionRollback
     * eventlistener methods
     *
     * @param string $savepoint                 Name of a savepoint to rollback to.
     * @throws Doctrine\DBAL\ConnectionException   If the rollback operation fails at database level.
     * @return boolean                          FALSE if rollback couldn't be performed, TRUE otherwise.
     */
    public function rollback()
	{
        if ($this->_transactionNestingLevel == 0) {
            throw ConnectionException::rollbackFailedNoActiveTransaction();
        }

        $this->connect();

        if ($this->_transactionNestingLevel == 1) {
            $this->_transactionNestingLevel = 0;
            $this->_conn->rollback();
        }
        --$this->_transactionNestingLevel;

        return true;
    }

    /**
     * Quotes pattern (% and _) characters in a string)
     *
     * EXPERIMENTAL
     *
     * WARNING: this function is experimental and may change signature at
     * any time until labelled as non-experimental
     *
     * @param   string  the input string to quote
     *
     * @return  string  quoted string
     */
    protected function _escapePattern($text)
    {
        return $text;
    }

    /**
     * Gets the wrapped driver connection.
     *
     * @return Doctrine\DBAL\Driver\Connection
     */
    public function getWrappedConnection()
    {
        $this->connect();
        return $this->_conn;
    }

    /**
     * Gets the SchemaManager that can be used to inspect or change the
     * database schema through the connection.
     *
     * @return Doctrine\DBAL\Schema\SchemaManager
     */
    public function getSchemaManager()
    {
        if ( ! $this->_schemaManager) {
            $this->_schemaManager = $this->_driver->getSchemaManager($this);
        }
        return $this->_schemaManager;
    }
}