system/database/drivers/sqlsrv/sqlsrv_driver.php
<?php
/**
* CodeIgniter
*
* An open source application development framework for PHP
*
* This content is released under the MIT License (MIT)
*
* Copyright (c) 2019 - 2022, CodeIgniter Foundation
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*
* @package CodeIgniter
* @author EllisLab Dev Team
* @copyright Copyright (c) 2008 - 2014, EllisLab, Inc. (https://ellislab.com/)
* @copyright Copyright (c) 2014 - 2019, British Columbia Institute of Technology (https://bcit.ca/)
* @copyright Copyright (c) 2019 - 2022, CodeIgniter Foundation (https://codeigniter.com/)
* @license https://opensource.org/licenses/MIT MIT License
* @link https://codeigniter.com
* @since Version 2.0.3
* @filesource
*/
defined('BASEPATH') OR exit('No direct script access allowed');
/**
* SQLSRV Database Adapter Class
*
* Note: _DB is an extender class that the app controller
* creates dynamically based on whether the query builder
* class is being used or not.
*
* @package CodeIgniter
* @subpackage Drivers
* @category Database
* @author EllisLab Dev Team
* @link https://codeigniter.com/userguide3/database/
*/
class CI_DB_sqlsrv_driver extends CI_DB {
/**
* Database driver
*
* @var string
*/
public $dbdriver = 'sqlsrv';
/**
* Scrollable flag
*
* Determines what cursor type to use when executing queries.
*
* FALSE or SQLSRV_CURSOR_FORWARD would increase performance,
* but would disable num_rows() (and possibly insert_id())
*
* @var mixed
*/
public $scrollable;
// --------------------------------------------------------------------
/**
* ORDER BY random keyword
*
* @var array
*/
protected $_random_keyword = array('NEWID()', 'RAND(%d)');
/**
* Quoted identifier flag
*
* Whether to use SQL-92 standard quoted identifier
* (double quotes) or brackets for identifier escaping.
*
* @var bool
*/
protected $_quoted_identifier = TRUE;
// --------------------------------------------------------------------
/**
* Class constructor
*
* @param array $params
* @return void
*/
public function __construct($params)
{
parent::__construct($params);
// This is only supported as of SQLSRV 3.0
if ($this->scrollable === NULL)
{
$this->scrollable = defined('SQLSRV_CURSOR_CLIENT_BUFFERED')
? SQLSRV_CURSOR_CLIENT_BUFFERED
: FALSE;
}
}
// --------------------------------------------------------------------
/**
* Database connection
*
* @param bool $pooling
* @return resource
*/
public function db_connect($pooling = FALSE)
{
$charset = in_array(strtolower($this->char_set), array('utf-8', 'utf8'), TRUE)
? 'UTF-8' : SQLSRV_ENC_CHAR;
$connection = array(
'UID' => empty($this->username) ? '' : $this->username,
'PWD' => empty($this->password) ? '' : $this->password,
'Database' => $this->database,
'ConnectionPooling' => ($pooling === TRUE) ? 1 : 0,
'CharacterSet' => $charset,
'Encrypt' => ($this->encrypt === TRUE) ? 1 : 0,
'ReturnDatesAsStrings' => 1
);
// If the username and password are both empty, assume this is a
// 'Windows Authentication Mode' connection.
if (empty($connection['UID']) && empty($connection['PWD']))
{
unset($connection['UID'], $connection['PWD']);
}
if (FALSE !== ($this->conn_id = sqlsrv_connect($this->hostname, $connection)))
{
// Determine how identifiers are escaped
$query = $this->query('SELECT CASE WHEN (@@OPTIONS | 256) = @@OPTIONS THEN 1 ELSE 0 END AS qi');
$query = $query->row_array();
$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
}
return $this->conn_id;
}
// --------------------------------------------------------------------
/**
* Select the database
*
* @param string $database
* @return bool
*/
public function db_select($database = '')
{
if ($database === '')
{
$database = $this->database;
}
if ($this->_execute('USE '.$this->escape_identifiers($database)))
{
$this->database = $database;
$this->data_cache = array();
return TRUE;
}
return FALSE;
}
// --------------------------------------------------------------------
/**
* Execute the query
*
* @param string $sql an SQL query
* @return resource
*/
protected function _execute($sql)
{
return ($this->scrollable === FALSE OR $this->is_write_type($sql))
? sqlsrv_query($this->conn_id, $sql)
: sqlsrv_query($this->conn_id, $sql, NULL, array('Scrollable' => $this->scrollable));
}
// --------------------------------------------------------------------
/**
* Begin Transaction
*
* @return bool
*/
protected function _trans_begin()
{
return sqlsrv_begin_transaction($this->conn_id);
}
// --------------------------------------------------------------------
/**
* Commit Transaction
*
* @return bool
*/
protected function _trans_commit()
{
return sqlsrv_commit($this->conn_id);
}
// --------------------------------------------------------------------
/**
* Rollback Transaction
*
* @return bool
*/
protected function _trans_rollback()
{
return sqlsrv_rollback($this->conn_id);
}
// --------------------------------------------------------------------
/**
* Affected Rows
*
* @return int
*/
public function affected_rows()
{
return sqlsrv_rows_affected($this->result_id);
}
// --------------------------------------------------------------------
/**
* Insert ID
*
* Returns the last id created in the Identity column.
*
* @return string
*/
public function insert_id()
{
return $this->query('SELECT SCOPE_IDENTITY() AS insert_id')->row()->insert_id;
}
// --------------------------------------------------------------------
/**
* Database version number
*
* @return string
*/
public function version()
{
if (isset($this->data_cache['version']))
{
return $this->data_cache['version'];
}
if ( ! $this->conn_id OR ($info = sqlsrv_server_info($this->conn_id)) === FALSE)
{
return FALSE;
}
return $this->data_cache['version'] = $info['SQLServerVersion'];
}
// --------------------------------------------------------------------
/**
* List table query
*
* Generates a platform-specific query string so that the table names can be fetched
*
* @param bool
* @return string $prefix_limit
*/
protected function _list_tables($prefix_limit = FALSE)
{
$sql = 'SELECT '.$this->escape_identifiers('name')
.' FROM '.$this->escape_identifiers('sysobjects')
.' WHERE '.$this->escape_identifiers('type')." = 'U'";
if ($prefix_limit === TRUE && $this->dbprefix !== '')
{
$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
.sprintf($this->_escape_like_str, $this->_escape_like_chr);
}
return $sql.' ORDER BY '.$this->escape_identifiers('name');
}
// --------------------------------------------------------------------
/**
* List column query
*
* Generates a platform-specific query string so that the column names can be fetched
*
* @param string $table
* @return string
*/
protected function _list_columns($table = '')
{
return 'SELECT COLUMN_NAME
FROM INFORMATION_SCHEMA.Columns
WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
}
// --------------------------------------------------------------------
/**
* Returns an object with field data
*
* @param string $table
* @return array
*/
public function field_data($table)
{
$sql = 'SELECT COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, NUMERIC_PRECISION, COLUMN_DEFAULT
FROM INFORMATION_SCHEMA.Columns
WHERE UPPER(TABLE_NAME) = '.$this->escape(strtoupper($table));
if (($query = $this->query($sql)) === FALSE)
{
return FALSE;
}
$query = $query->result_object();
$retval = array();
for ($i = 0, $c = count($query); $i < $c; $i++)
{
$retval[$i] = new stdClass();
$retval[$i]->name = $query[$i]->COLUMN_NAME;
$retval[$i]->type = $query[$i]->DATA_TYPE;
$retval[$i]->max_length = ($query[$i]->CHARACTER_MAXIMUM_LENGTH > 0) ? $query[$i]->CHARACTER_MAXIMUM_LENGTH : $query[$i]->NUMERIC_PRECISION;
$retval[$i]->default = $query[$i]->COLUMN_DEFAULT;
}
return $retval;
}
// --------------------------------------------------------------------
/**
* Error
*
* Returns an array containing code and message of the last
* database error that has occurred.
*
* @return array
*/
public function error()
{
$error = array('code' => '00000', 'message' => '');
$sqlsrv_errors = sqlsrv_errors(SQLSRV_ERR_ERRORS);
if ( ! is_array($sqlsrv_errors))
{
return $error;
}
$sqlsrv_error = array_shift($sqlsrv_errors);
if (isset($sqlsrv_error['SQLSTATE']))
{
$error['code'] = isset($sqlsrv_error['code']) ? $sqlsrv_error['SQLSTATE'].'/'.$sqlsrv_error['code'] : $sqlsrv_error['SQLSTATE'];
}
elseif (isset($sqlsrv_error['code']))
{
$error['code'] = $sqlsrv_error['code'];
}
if (isset($sqlsrv_error['message']))
{
$error['message'] = $sqlsrv_error['message'];
}
return $error;
}
// --------------------------------------------------------------------
/**
* Update statement
*
* Generates a platform-specific update string from the supplied data
*
* @param string $table
* @param array $values
* @return string
*/
protected function _update($table, $values)
{
$this->qb_limit = FALSE;
$this->qb_orderby = array();
return parent::_update($table, $values);
}
// --------------------------------------------------------------------
/**
* Truncate statement
*
* Generates a platform-specific truncate string from the supplied data
*
* If the database does not support the TRUNCATE statement,
* then this method maps to 'DELETE FROM table'
*
* @param string $table
* @return string
*/
protected function _truncate($table)
{
return 'TRUNCATE TABLE '.$table;
}
// --------------------------------------------------------------------
/**
* Delete statement
*
* Generates a platform-specific delete string from the supplied data
*
* @param string $table
* @return string
*/
protected function _delete($table)
{
if ($this->qb_limit)
{
return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
}
return parent::_delete($table);
}
// --------------------------------------------------------------------
/**
* LIMIT
*
* Generates a platform-specific LIMIT clause
*
* @param string $sql SQL Query
* @return string
*/
protected function _limit($sql)
{
// As of SQL Server 2012 (11.0.*) OFFSET is supported
if (version_compare($this->version(), '11', '>='))
{
// SQL Server OFFSET-FETCH can be used only with the ORDER BY clause
empty($this->qb_orderby) && $sql .= ' ORDER BY 1';
return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
}
$limit = $this->qb_offset + $this->qb_limit;
// An ORDER BY clause is required for ROW_NUMBER() to work
if ($this->qb_offset && ! empty($this->qb_orderby))
{
$orderby = $this->_compile_order_by();
// We have to strip the ORDER BY clause
$sql = trim(substr($sql, 0, strrpos($sql, $orderby)));
// Get the fields to select from our subquery, so that we can avoid CI_rownum appearing in the actual results
if (count($this->qb_select) === 0 OR strpos(implode(',', $this->qb_select), '*') !== FALSE)
{
$select = '*'; // Inevitable
}
else
{
// Use only field names and their aliases, everything else is out of our scope.
$select = array();
$field_regexp = ($this->_quoted_identifier)
? '("[^\"]+")' : '(\[[^\]]+\])';
for ($i = 0, $c = count($this->qb_select); $i < $c; $i++)
{
$select[] = preg_match('/(?:\s|\.)'.$field_regexp.'$/i', $this->qb_select[$i], $m)
? $m[1] : $this->qb_select[$i];
}
$select = implode(', ', $select);
}
return 'SELECT '.$select." FROM (\n\n"
.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.trim($orderby).') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
."\n\n) ".$this->escape_identifiers('CI_subquery')
."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
}
return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
}
// --------------------------------------------------------------------
/**
* Insert batch statement
*
* Generates a platform-specific insert string from the supplied data.
*
* @param string $table Table name
* @param array $keys INSERT keys
* @param array $values INSERT values
* @return string|bool
*/
protected function _insert_batch($table, $keys, $values)
{
// Multiple-value inserts are only supported as of SQL Server 2008
if (version_compare($this->version(), '10', '>='))
{
return parent::_insert_batch($table, $keys, $values);
}
return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
}
// --------------------------------------------------------------------
/**
* Close DB Connection
*
* @return void
*/
protected function _close()
{
sqlsrv_close($this->conn_id);
}
}