Remove _limit()'s extra parameters and qb_limit, qb_offset unneeded typecasts + add _compile_group_by() method

13 files changed, 58 insertions, 87 deletions

diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index 86c1fee6d..7b37b9999 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -285,7 +285,10 @@ class CI_DB_ibase_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return $this->_limit('SELECT * FROM '.$this->protect_identifiers($table), 1, NULL);
+		$this->qb_limit = 1;
+		$sql = $this->_limit('SELECT * FROM '.$this->protect_identifiers($table));
+		$this->qb_limit = 0;
+		return $sql;
 	}
 
 	// --------------------------------------------------------------------
@@ -378,22 +381,20 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// Limit clause depends on if Interbase or Firebird
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
-			$select = 'FIRST '. (int) $limit
-				.($offset ? ' SKIP '. (int) $offset : '');
+			$select = 'FIRST '.$this->qb_limit
+				.($this->qb_offset ? ' SKIP '.$this->qb_offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($this->qb_offset ? $this->qb_offset.' TO '.($this->qb_limit + $this->qb_offset) : $this->qb_limit);
 		}
 
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 35cd85702..bfc82a6c2 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -429,7 +429,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	{
 		if ($this->qb_limit)
 		{
-			return 'WITH ci_delete AS (SELECT TOP '.(int) $this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
 		}
 
 		return parent::_delete($table);
@@ -443,25 +443,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		// As of SQL Server 2012 (11.0.*) OFFSET is supported
-		if (version_compare($this->version(), '11', '>='))
-		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
-		}
-
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// As of SQL Server 2005 (9.0.*) ROW_NUMBER() is supported,
 		// however an ORDER BY clause is required for it to work
-		if (version_compare($this->version(), '9', '>=') && $offset && ! empty($this->qb_orderby))
+		if (version_compare($this->version(), '9', '>=') && $this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = trim($this->_compile_order_by());
 
 			// We have to strip the ORDER BY clause
 			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
@@ -469,7 +461,7 @@ class CI_DB_mssql_driver extends CI_DB {
 			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
 				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
 				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index a0f26c257..dcc46527c 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -617,7 +617,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	{
 		if ($this->qb_limit)
 		{
-			$this->where('rownum <= ', (int) $this->qb_limit, FALSE);
+			$this->where('rownum <= ',$this->qb_limit, FALSE);
 			$this->qb_limit = FALSE;
 		}
 
@@ -632,15 +632,13 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		$this->limit_used = TRUE;
-		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit + 1).')'
-			.($offset ? ' WHERE rnum >= '.($offset + 1): '');
+		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
+			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1): '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
index 014112401..0e6877c28 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_4d_driver.php
@@ -185,13 +185,11 @@ class CI_DB_pdo_4d_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 20d510ff6..ad699ce23 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -198,7 +198,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	{
 		if ($this->qb_limit)
 		{
-			return 'WITH ci_delete AS (SELECT TOP '.(int) $this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
 		}
 
 		return parent::_delete($table);
@@ -212,19 +212,17 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// As of SQL Server 2005 (9.0.*) ROW_NUMBER() is supported,
 		// however an ORDER BY clause is required for it to work
-		if (version_compare($this->version(), '9', '>=') && $offset && ! empty($this->qb_orderby))
+		if (version_compare($this->version(), '9', '>=') && $this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = trim($this->_compile_order_by());
 
 			// We have to strip the ORDER BY clause
 			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
@@ -232,7 +230,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
 				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
 				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
@@ -241,4 +239,4 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 }
 
 /* End of file pdo_dblib_driver.php */
-/* Location: ./system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index ee21ed22f..5b36342d2 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -211,22 +211,20 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// Limit clause depends on if Interbase or Firebird
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
-			$select = 'FIRST '. (int) $limit
-				.($offset > 0 ? ' SKIP '. (int) $offset : '');
+			$select = 'FIRST '.$this->qb_limit
+				.($this->qb_offset > 0 ? ' SKIP '.$this->qb_offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset > 0 ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($this->qb_offset > 0 ? $this->qb_offset.' TO '.($this->qb_limit + $this->qb_offset) : $this->qb_limit);
 		}
 
 		return preg_replace('`SELECT`i', 'SELECT '.$select, $sql);
diff --git a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
index a6869a7d2..82480498a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_informix_driver.php
@@ -232,13 +232,11 @@ class CI_DB_pdo_informix_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		$select = 'SELECT '.($offset ? 'SKIP '.$offset : '').'FIRST '.$limit.' ';
+		$select = 'SELECT '.($this->qb_offset ? 'SKIP '.$this->qb_offset : '').'FIRST '.$this->qb_limit.' ';
 		return preg_replace('/^(SELECT\s)/i', $select, $sql, 1);
 	}
 
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
index 494d82c3f..cfbb639a8 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_driver.php
@@ -196,7 +196,7 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	{
 		if ($this->qb_limit)
 		{
-			$this->where('rownum <= ', (int) $this->qb_limit, FALSE);
+			$this->where('rownum <= ',$this->qb_limit, FALSE);
 			$this->qb_limit = FALSE;
 		}
 
@@ -211,14 +211,12 @@ class CI_DB_pdo_oci_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit + 1).')'
-			.($offset ? ' WHERE rnum >= '.($offset + 1): '');
+		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($this->qb_offset + $this->qb_limit + 1).')'
+			.($this->qb_offset ? ' WHERE rnum >= '.($this->qb_offset + 1): '');
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index 722acad89..0c3467484 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -230,13 +230,11 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
+		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$this->qb_limit.' ', $sql);
 	}
 
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
index 510a2a38f..07cf8f56b 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_driver.php
@@ -238,13 +238,11 @@ class CI_DB_pdo_pgsql_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index 39cb5f9ef..399d134af 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -227,7 +227,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	{
 		if ($this->qb_limit)
 		{
-			return 'WITH ci_delete AS (SELECT TOP '.(int) $this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
 		}
 
 		return parent::_delete($table);
@@ -241,24 +241,22 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// As of SQL Server 2012 (11.0.*) OFFSET is supported
 		if (version_compare($this->version(), '11', '>='))
 		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
 		}
 
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// An ORDER BY clause is required for ROW_NUMBER() to work
-		if ($offset && ! empty($this->qb_orderby))
+		if ($this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = trim($this->_compile_order_by());
 
 			// We have to strip the ORDER BY clause
 			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
@@ -266,7 +264,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
 				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
 				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);
@@ -275,4 +273,4 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 }
 
 /* End of file pdo_sqlsrv_driver.php */
-/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php */
+/* Location: ./system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php */
\ No newline at end of file
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index 1c03f6831..ddcf3f7c3 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -549,13 +549,11 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
-		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
+		return $sql.' LIMIT '.$this->qb_limit.($this->qb_offset ? ' OFFSET '.$this->qb_offset : '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 9ea6facb3..4eb12f910 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -425,7 +425,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	{
 		if ($this->qb_limit)
 		{
-			return 'WITH ci_delete AS (SELECT TOP '.(int) $this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
+			return 'WITH ci_delete AS (SELECT TOP '.$this->qb_limit.' * FROM '.$table.$this->_compile_wh('qb_where').') DELETE FROM ci_delete';
 		}
 
 		return parent::_delete($table);
@@ -439,24 +439,22 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Generates a platform-specific LIMIT clause
 	 *
 	 * @param	string	the sql query string
-	 * @param	int	the number of rows to limit the query to
-	 * @param	int	the offset value
 	 * @return	string
 	 */
-	protected function _limit($sql, $limit, $offset)
+	protected function _limit($sql)
 	{
 		// As of SQL Server 2012 (11.0.*) OFFSET is supported
 		if (version_compare($this->version(), '11', '>='))
 		{
-			return $sql.' OFFSET '.(int) $offset.' ROWS FETCH NEXT '.(int) $limit.' ROWS ONLY';
+			return $sql.' OFFSET '.(int) $this->qb_offset.' ROWS FETCH NEXT '.$this->qb_limit.' ROWS ONLY';
 		}
 
-		$limit = $offset + $limit;
+		$limit = $this->qb_offset + $this->qb_limit;
 
 		// An ORDER BY clause is required for ROW_NUMBER() to work
-		if ($offset && ! empty($this->qb_orderby))
+		if ($this->qb_offset && ! empty($this->qb_orderby))
 		{
-			$orderby = 'ORDER BY '.implode(', ', $this->qb_orderby);
+			$orderby = trim($this->_compile_order_by());
 
 			// We have to strip the ORDER BY clause
 			$sql = trim(substr($sql, 0, strrpos($sql, 'ORDER BY '.$orderby)));
@@ -464,7 +462,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 			return 'SELECT '.(count($this->qb_select) === 0 ? '*' : implode(', ', $this->qb_select))." FROM (\n"
 				.preg_replace('/^(SELECT( DISTINCT)?)/i', '\\1 ROW_NUMBER() OVER('.$orderby.') AS '.$this->escape_identifiers('CI_rownum').', ', $sql)
 				."\n) ".$this->escape_identifiers('CI_subquery')
-				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.((int) $offset + 1).' AND '.$limit;
+				."\nWHERE ".$this->escape_identifiers('CI_rownum').' BETWEEN '.($this->qb_offset + 1).' AND '.$limit;
 		}
 
 		return preg_replace('/(^\SELECT (DISTINCT)?)/i','\\1 TOP '.$limit.' ', $sql);