<?php

/**

 * Zend Framework

 *

 * LICENSE

 *

 * This source file is subject to the new BSD license that is bundled

 * with this package in the file LICENSE.txt.

 * It is also available through the world-wide-web at this URL:

 * http://framework.zend.com/license/new-bsd

 * If you did not receive a copy of the license and are unable to

 * obtain it through the world-wide-web, please send an email

 * to license@zend.com so we can send you a copy immediately.

 *

 * @category   Zend

 * @package    Zend_Db

 * @subpackage Adapter

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 * @version    $Id: Pgsql.php 22788 2010-08-03 18:29:55Z ramon $

 */

/**

 * @see Zend_Db_Adapter_Pdo_Abstract

 */

require_once 'Zend/Db/Adapter/Pdo/Abstract.php';

/**

 * Class for connecting to PostgreSQL databases and performing common operations.

 *

 * @category   Zend

 * @package    Zend_Db

 * @subpackage Adapter

 * @copyright  Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)

 * @license    http://framework.zend.com/license/new-bsd     New BSD License

 */

class Zend_Db_Adapter_Pdo_Pgsql extends Zend_Db_Adapter_Pdo_Abstract

{

    /**

     * PDO type.

     *

     * @var string

     */

    protected $_pdoType = 'pgsql';

    /**

     * Keys are UPPERCASE SQL datatypes or the constants

     * Zend_Db::INT_TYPE, Zend_Db::BIGINT_TYPE, or Zend_Db::FLOAT_TYPE.

     *

     * Values are:

     * 0 = 32-bit integer

     * 1 = 64-bit integer

     * 2 = float or decimal

     *

     * @var array Associative array of datatypes to values 0, 1, or 2.

     */

    protected $_numericDataTypes = array(

        Zend_Db::INT_TYPE    => Zend_Db::INT_TYPE,

        Zend_Db::BIGINT_TYPE => Zend_Db::BIGINT_TYPE,

        Zend_Db::FLOAT_TYPE  => Zend_Db::FLOAT_TYPE,

        'INTEGER'            => Zend_Db::INT_TYPE,

        'SERIAL'             => Zend_Db::INT_TYPE,

        'SMALLINT'           => Zend_Db::INT_TYPE,

        'BIGINT'             => Zend_Db::BIGINT_TYPE,

        'BIGSERIAL'          => Zend_Db::BIGINT_TYPE,

        'DECIMAL'            => Zend_Db::FLOAT_TYPE,

        'DOUBLE PRECISION'   => Zend_Db::FLOAT_TYPE,

        'NUMERIC'            => Zend_Db::FLOAT_TYPE,

        'REAL'               => Zend_Db::FLOAT_TYPE

    );

    /**

     * Creates a PDO object and connects to the database.

     *

     * @return void

     * @throws Zend_Db_Adapter_Exception

     */

    protected function _connect()

    {

        if ($this->_connection) {

            return;

        }

        parent::_connect();

        if (!empty($this->_config['charset'])) {

            $sql = "SET NAMES '" . $this->_config['charset'] . "'";

            $this->_connection->exec($sql);

        }

    }

    /**

     * Returns a list of the tables in the database.

     *

     * @return array

     */

    public function listTables()

    {

        // @todo use a better query with joins instead of subqueries

        $sql = "SELECT c.relname AS table_name "

             . "FROM pg_class c, pg_user u "

             . "WHERE c.relowner = u.usesysid AND c.relkind = 'r' "

             . "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) "

             . "AND c.relname !~ '^(pg_|sql_)' "

             . "UNION "

             . "SELECT c.relname AS table_name "

             . "FROM pg_class c "

             . "WHERE c.relkind = 'r' "

             . "AND NOT EXISTS (SELECT 1 FROM pg_views WHERE viewname = c.relname) "

             . "AND NOT EXISTS (SELECT 1 FROM pg_user WHERE usesysid = c.relowner) "

             . "AND c.relname !~ '^pg_'";

        return $this->fetchCol($sql);

    }

    /**

     * Returns the column descriptions for a table.

     *

     * The return value is an associative array keyed by the column name,

     * as returned by the RDBMS.

     *

     * The value of each array element is an associative array

     * with the following keys:

     *

     * SCHEMA_NAME      => string; name of database or schema

     * TABLE_NAME       => string;

     * COLUMN_NAME      => string; column name

     * COLUMN_POSITION  => number; ordinal position of column in table

     * DATA_TYPE        => string; SQL datatype name of column

     * DEFAULT          => string; default expression of column, null if none

     * NULLABLE         => boolean; true if column can have nulls

     * LENGTH           => number; length of CHAR/VARCHAR

     * SCALE            => number; scale of NUMERIC/DECIMAL

     * PRECISION        => number; precision of NUMERIC/DECIMAL

     * UNSIGNED         => boolean; unsigned property of an integer type

     * PRIMARY          => boolean; true if column is part of the primary key

     * PRIMARY_POSITION => integer; position of column in primary key

     * IDENTITY         => integer; true if column is auto-generated with unique values

     *

     * @todo Discover integer unsigned property.

     *

     * @param  string $tableName

     * @param  string $schemaName OPTIONAL

     * @return array

     */

    public function describeTable($tableName, $schemaName = null)

    {

        $sql = "SELECT

                a.attnum,

                n.nspname,

                c.relname,

                a.attname AS colname,

                t.typname AS type,

                a.atttypmod,

                FORMAT_TYPE(a.atttypid, a.atttypmod) AS complete_type,

                d.adsrc AS default_value,

                a.attnotnull AS notnull,

                a.attlen AS length,

                co.contype,

                ARRAY_TO_STRING(co.conkey, ',') AS conkey

            FROM pg_attribute AS a

                JOIN pg_class AS c ON a.attrelid = c.oid

                JOIN pg_namespace AS n ON c.relnamespace = n.oid

                JOIN pg_type AS t ON a.atttypid = t.oid

                LEFT OUTER JOIN pg_constraint AS co ON (co.conrelid = c.oid

                    AND a.attnum = ANY(co.conkey) AND co.contype = 'p')

                LEFT OUTER JOIN pg_attrdef AS d ON d.adrelid = c.oid AND d.adnum = a.attnum

            WHERE a.attnum > 0 AND c.relname = ".$this->quote($tableName);

        if ($schemaName) {

            $sql .= " AND n.nspname = ".$this->quote($schemaName);

        }

        $sql .= ' ORDER BY a.attnum';

        $stmt = $this->query($sql);

        // Use FETCH_NUM so we are not dependent on the CASE attribute of the PDO connection

        $result = $stmt->fetchAll(Zend_Db::FETCH_NUM);

        $attnum        = 0;

        $nspname       = 1;

        $relname       = 2;

        $colname       = 3;

        $type          = 4;

        $atttypemod    = 5;

        $complete_type = 6;

        $default_value = 7;

        $notnull       = 8;

        $length        = 9;

        $contype       = 10;

        $conkey        = 11;

        $desc = array();

        foreach ($result as $key => $row) {

            $defaultValue = $row[$default_value];

            if ($row[$type] == 'varchar' || $row[$type] == 'bpchar' ) {

                if (preg_match('/character(?: varying)?(?:\((\d+)\))?/', $row[$complete_type], $matches)) {

                    if (isset($matches[1])) {

                        $row[$length] = $matches[1];

                    } else {

                        $row[$length] = null; // unlimited

                    }

                }

                if (preg_match("/^'(.*?)'::(?:character varying|bpchar)$/", $defaultValue, $matches)) {

                    $defaultValue = $matches[1];

                }

            }

            list($primary, $primaryPosition, $identity) = array(false, null, false);

            if ($row[$contype] == 'p') {

                $primary = true;

                $primaryPosition = array_search($row[$attnum], explode(',', $row[$conkey])) + 1;

                $identity = (bool) (preg_match('/^nextval/', $row[$default_value]));

            }

            $desc[$this->foldCase($row[$colname])] = array(

                'SCHEMA_NAME'      => $this->foldCase($row[$nspname]),

                'TABLE_NAME'       => $this->foldCase($row[$relname]),

                'COLUMN_NAME'      => $this->foldCase($row[$colname]),

                'COLUMN_POSITION'  => $row[$attnum],

                'DATA_TYPE'        => $row[$type],

                'DEFAULT'          => $defaultValue,

                'NULLABLE'         => (bool) ($row[$notnull] != 't'),

                'LENGTH'           => $row[$length],

                'SCALE'            => null, // @todo

                'PRECISION'        => null, // @todo

                'UNSIGNED'         => null, // @todo

                'PRIMARY'          => $primary,

                'PRIMARY_POSITION' => $primaryPosition,

                'IDENTITY'         => $identity

            );

        }

        return $desc;

    }

    /**

     * Adds an adapter-specific LIMIT clause to the SELECT statement.

     *

     * @param string $sql

     * @param integer $count

     * @param integer $offset OPTIONAL

     * @return string

     */

    public function limit($sql, $count, $offset = 0)

    {

        $count = intval($count);

        if ($count <= 0) {

            /**

             * @see Zend_Db_Adapter_Exception

             */

            require_once 'Zend/Db/Adapter/Exception.php';

            throw new Zend_Db_Adapter_Exception("LIMIT argument count=$count is not valid");

        }

        $offset = intval($offset);

        if ($offset < 0) {

            /**

             * @see Zend_Db_Adapter_Exception

             */

            require_once 'Zend/Db/Adapter/Exception.php';

            throw new Zend_Db_Adapter_Exception("LIMIT argument offset=$offset is not valid");

        }

        $sql .= " LIMIT $count";

        if ($offset > 0) {

            $sql .= " OFFSET $offset";

        }

        return $sql;

    }

    /**

     * Return the most recent value from the specified sequence in the database.

     * This is supported only on RDBMS brands that support sequences

     * (e.g. Oracle, PostgreSQL, DB2).  Other RDBMS brands return null.

     *

     * @param string $sequenceName

     * @return string

     */

    public function lastSequenceId($sequenceName)

    {

        $this->_connect();

        $sequenceName = str_replace($this->getQuoteIdentifierSymbol(), '', (string) $sequenceName);

        $value = $this->fetchOne("SELECT CURRVAL("

               . $this->quote($this->quoteIdentifier($sequenceName, true))

               . ")");

        return $value;

    }

    /**

     * Generate a new value from the specified sequence in the database, and return it.

     * This is supported only on RDBMS brands that support sequences

     * (e.g. Oracle, PostgreSQL, DB2).  Other RDBMS brands return null.

     *

     * @param string $sequenceName

     * @return string

     */

    public function nextSequenceId($sequenceName)

    {

        $this->_connect();

        $sequenceName = str_replace($this->getQuoteIdentifierSymbol(), '', (string) $sequenceName);

        $value = $this->fetchOne("SELECT NEXTVAL("

               . $this->quote($this->quoteIdentifier($sequenceName, true))

               . ")");

        return $value;

    }

    /**

     * Gets the last ID generated automatically by an IDENTITY/AUTOINCREMENT column.

     *

     * As a convention, on RDBMS brands that support sequences

     * (e.g. Oracle, PostgreSQL, DB2), this method forms the name of a sequence

     * from the arguments and returns the last id generated by that sequence.

     * On RDBMS brands that support IDENTITY/AUTOINCREMENT columns, this method

     * returns the last value generated for such a column, and the table name

     * argument is disregarded.

     *

     * @param string $tableName   OPTIONAL Name of table.

     * @param string $primaryKey  OPTIONAL Name of primary key column.

     * @return string

     */

    public function lastInsertId($tableName = null, $primaryKey = null)

    {

        if ($tableName !== null) {

            $sequenceName = $tableName;

            if ($primaryKey) {

                $sequenceName .= "_$primaryKey";

            }

            $sequenceName .= '_seq';

            return $this->lastSequenceId($sequenceName);

        }

        return $this->_connection->lastInsertId($tableName);

    }

}