doctrine2/lib/Doctrine/DBAL/Platforms/OraclePlatform.php

<?php
/*
 *  $Id$
 *
 * 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\Platforms;

/**
 * OraclePlatform.
 *
 * @since 2.0
 * @author Roman Borschel <roman@code-factory.org>
 * @author Lukas Smith <smith@pooteeweet.org> (PEAR MDB2 library)
 */
class OraclePlatform extends AbstractPlatform
{
    /**
     * Constructor.
     */
    public function __construct()
    {
        parent::__construct();
    }

    /**
     * return string to call a function to get a substring inside an SQL statement
     *
     * Note: Not SQL92, but common functionality.
     *
     * @param string $value         an sql string literal or column name/alias
     * @param integer $position     where to start the substring portion
     * @param integer $length       the substring portion length
     * @return string               SQL substring function with given parameters
     * @override
     */
    public function getSubstringExpression($value, $position, $length = null)
    {
        if ($length !== null) {
            return "SUBSTR($value, $position, $length)";
        }

        return "SUBSTR($value, $position)";
    }

    /**
     * Return string to call a variable with the current timestamp inside an SQL statement
     * There are three special variables for current date and time:
     * - CURRENT_TIMESTAMP (date and time, TIMESTAMP type)
     * - CURRENT_DATE (date, DATE type)
     * - CURRENT_TIME (time, TIME type)
     *
     * @return string to call a variable with the current timestamp
     * @override
     */
    public function getNowExpression($type = 'timestamp')
    {
        switch ($type) {
            case 'date':
            case 'time':
            case 'timestamp':
            default:
                return 'TO_CHAR(CURRENT_TIMESTAMP, \'YYYY-MM-DD HH24:MI:SS\')';
        }
    }

    /**
     * random
     *
     * @return string           an oracle SQL string that generates a float between 0 and 1
     * @override
     */
    public function getRandomExpression()
    {
        return 'dbms_random.value';
    }

    /**
     * Returns global unique identifier
     *
     * @return string to get global unique identifier
     * @override
     */
    public function getGuidExpression()
    {
        return 'SYS_GUID()';
    }

    /**
     * {@inheritdoc}
     *
     * @return string
     * @override
     */
    public function getCreateSequenceSql($sequenceName, $start = 1, $allocationSize = 1)
    {
        return 'CREATE SEQUENCE ' . $this->quoteIdentifier($sequenceName)
                . ' START WITH ' . $start . ' INCREMENT BY ' . $allocationSize;
    }
    
    /**
     * {@inheritdoc}
     *
     * @param string $sequenceName
     * @override
     */
    public function getSequenceNextValSql($sequenceName)
    {
        return 'SELECT ' . $this->quoteIdentifier($sequenceName) . '.nextval FROM DUAL';
    }
    
    /**
     * {@inheritdoc}
     *
     * @param integer $level
     * @override
     */
    public function getSetTransactionIsolationSql($level)
    {
        return 'SET TRANSACTION ISOLATION LEVEL ' . $this->_getTransactionIsolationLevelSql($level);
    }
    
    /**
     * Enter description here...
     *
     * @param integer $level
     * @override
     */
    protected function _getTransactionIsolationLevelSql($level)
    {
        switch ($level) {
            case Doctrine_DBAL_Connection::TRANSACTION_READ_UNCOMMITTED:
            case Doctrine_DBAL_Connection::TRANSACTION_READ_COMMITTED:
                return 'READ COMMITTED';
            case Doctrine_DBAL_Connection::TRANSACTION_REPEATABLE_READ:
            case Doctrine_DBAL_Connection::TRANSACTION_SERIALIZABLE:
                return 'SERIALIZABLE';
            default:
                return parent::_getTransactionIsolationLevelSql($level);
        }
    }

    /**
     * @override
     */
    public function getIntegerTypeDeclarationSql(array $field)
    {
        return 'NUMBER(10)';
    }

    /**
     * @override
     */
    public function getBigIntTypeDeclarationSql(array $field)
    {
        return 'NUMBER(20)';
    }

    /**
     * @override
     */
    public function getSmallIntTypeDeclarationSql(array $field)
    {
        return 'NUMBER(5)';
    }

    /**
     * @override
     */
    protected function _getCommonIntegerTypeDeclarationSql(array $columnDef)
    {
        return '';
    }

    /**
     * Gets the SQL snippet used to declare a VARCHAR column on the Oracle platform.
     *
     * @params array $field
     * @override
     */
    public function getVarcharTypeDeclarationSql(array $field)
    {
        if ( ! isset($field['length'])) {
            if (array_key_exists('default', $field)) {
                $field['length'] = $this->getVarcharMaxLength();
            } else {
                $field['length'] = false;
            }
        }

        $length = ($field['length'] <= $this->getVarcharMaxLength()) ? $field['length'] : false;
        $fixed = (isset($field['fixed'])) ? $field['fixed'] : false;

        return $fixed ? ($length ? 'CHAR(' . $length . ')' : 'CHAR(2000)')
                : ($length ? 'VARCHAR2(' . $length . ')' : 'VARCHAR2(4000)');
    }

    /**
     * Whether the platform prefers sequences for ID generation.
     *
     * @return boolean
     */
    public function prefersSequences()
    {
        return true;
    }

    /**
     * Get the platform name for this instance
     *
     * @return string
     */
    public function getName()
    {
        return 'oracle';
    }
}