Merge branch '3.1-stable'

27 files changed, 163 insertions, 85 deletions

diff --git a/system/database/DB_cache.php b/system/database/DB_cache.php
index b74c31924..7c8ee5fc9 100644
--- a/system/database/DB_cache.php
+++ b/system/database/DB_cache.php
@@ -143,7 +143,7 @@ class CI_DB_Cache {
 		$segment_two = ($this->CI->uri->segment(2) == FALSE) ? 'index' : $this->CI->uri->segment(2);
 		$filepath = $this->db->cachedir.$segment_one.'+'.$segment_two.'/'.md5($sql);
 
-		if (FALSE === ($cachedata = @file_get_contents($filepath)))
+		if ( ! is_file($filepath) OR FALSE === ($cachedata = file_get_contents($filepath)))
 		{
 			return FALSE;
 		}
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index 19afdd492..0b13a2f82 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -916,6 +916,7 @@ abstract class CI_DB_driver {
 
 		if ($this->_trans_begin())
 		{
+			$this->_trans_status = TRUE;
 			$this->_trans_depth++;
 			return TRUE;
 		}
@@ -1044,7 +1045,7 @@ abstract class CI_DB_driver {
 	 */
 	public function is_write_type($sql)
 	{
-		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX)\s/i', $sql);
+		return (bool) preg_match('/^\s*"?(SET|INSERT|UPDATE|DELETE|REPLACE|CREATE|DROP|TRUNCATE|LOAD|COPY|ALTER|RENAME|GRANT|REVOKE|LOCK|UNLOCK|REINDEX|MERGE)\s/i', $sql);
 	}
 
 	// --------------------------------------------------------------------
@@ -1173,14 +1174,14 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		return str_replace("'", "''", remove_invisible_characters($str));
+		return str_replace("'", "''", remove_invisible_characters($str, FALSE));
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 7289235c8..3cb02ca4e 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -488,7 +488,7 @@ abstract class CI_DB_forge {
 	 *
 	 * @param	string	$table		Table name
 	 * @param	bool	$if_exists	Whether to add an IF EXISTS condition
-	 * @return	string
+	 * @return	mixed	(Returns a platform-specific DROP table string, or TRUE to indicate there's nothing to do)
 	 */
 	protected function _drop_table($table, $if_exists)
 	{
@@ -979,8 +979,8 @@ abstract class CI_DB_forge {
 	/**
 	 * Process indexes
 	 *
-	 * @param	string	$table
-	 * @return	string
+	 * @param	string	$table	Table name
+	 * @return	string[] list of SQL statements
 	 */
 	protected function _process_indexes($table)
 	{
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index ab19d97a2..81603bf31 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -215,6 +215,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	protected $qb_cache_join			= array();
 
 	/**
+	 * QB Cache aliased tables list
+	 *
+	 * @var	array
+	 */
+	protected $qb_cache_aliased_tables			= array();
+
+	/**
 	 * QB Cache WHERE data
 	 *
 	 * @var	array
@@ -1396,13 +1403,11 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		// ORDER BY usage is often problematic here (most notably
 		// on Microsoft SQL Server) and ultimately unnecessary
 		// for selecting COUNT(*) ...
-		if ( ! empty($this->qb_orderby))
-		{
-			$orderby = $this->qb_orderby;
-			$this->qb_orderby = NULL;
-		}
+		$qb_orderby       = $this->qb_orderby;
+		$qb_cache_orderby = $this->qb_cache_orderby;
+		$this->qb_orderby = $this->qb_cache_orderby = NULL;
 
-		$result = ($this->qb_distinct === TRUE OR ! empty($this->qb_groupby) OR ! empty($this->qb_cache_groupby))
+		$result = ($this->qb_distinct === TRUE OR ! empty($this->qb_groupby) OR ! empty($this->qb_cache_groupby) OR $this->qb_limit OR $this->qb_offset)
 			? $this->query($this->_count_string.$this->protect_identifiers('numrows')."\nFROM (\n".$this->_compile_select()."\n) CI_count_all_results")
 			: $this->query($this->_compile_select($this->_count_string.$this->protect_identifiers('numrows')));
 
@@ -1410,10 +1415,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		{
 			$this->_reset_select();
 		}
-		// If we've previously reset the qb_orderby values, get them back
-		elseif ( ! isset($this->qb_orderby))
+		else
 		{
-			$this->qb_orderby = $orderby;
+			$this->qb_orderby       = $qb_orderby;
+			$this->qb_cache_orderby = $qb_cache_orderby;
 		}
 
 		if ($result->num_rows() === 0)
@@ -2281,9 +2286,14 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$table = trim(strrchr($table, ' '));
 
 			// Store the alias, if it doesn't already exist
-			if ( ! in_array($table, $this->qb_aliased_tables))
+			if ( ! in_array($table, $this->qb_aliased_tables, TRUE))
 			{
 				$this->qb_aliased_tables[] = $table;
+				if ($this->qb_caching === TRUE && ! in_array($table, $this->qb_cache_aliased_tables, TRUE))
+				{
+					$this->qb_cache_aliased_tables[] = $table;
+					$this->qb_cache_exists[] = 'aliased_tables';
+				}
 			}
 		}
 	}
@@ -2441,7 +2451,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Escapes identifiers in GROUP BY statements at execution time.
 	 *
-	 * Required so that aliases are tracked properly, regardless of wether
+	 * Required so that aliases are tracked properly, regardless of whether
 	 * group_by() is called prior to from(), join() and dbprefix is added
 	 * only if needed.
 	 *
@@ -2477,7 +2487,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 *
 	 * Escapes identifiers in ORDER BY statements at execution time.
 	 *
-	 * Required so that aliases are tracked properly, regardless of wether
+	 * Required so that aliases are tracked properly, regardless of whether
 	 * order_by() is called prior to from(), join() and dbprefix is added
 	 * only if needed.
 	 *
@@ -2485,26 +2495,27 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _compile_order_by()
 	{
-		if (is_array($this->qb_orderby) && count($this->qb_orderby) > 0)
+		if (empty($this->qb_orderby))
 		{
-			for ($i = 0, $c = count($this->qb_orderby); $i < $c; $i++)
+			return '';
+		}
+
+		for ($i = 0, $c = count($this->qb_orderby); $i < $c; $i++)
+		{
+			if (is_string($this->qb_orderby[$i]))
 			{
-				if ($this->qb_orderby[$i]['escape'] !== FALSE && ! $this->_is_literal($this->qb_orderby[$i]['field']))
-				{
-					$this->qb_orderby[$i]['field'] = $this->protect_identifiers($this->qb_orderby[$i]['field']);
-				}
+				continue;
+			}
 
-				$this->qb_orderby[$i] = $this->qb_orderby[$i]['field'].$this->qb_orderby[$i]['direction'];
+			if ($this->qb_orderby[$i]['escape'] !== FALSE && ! $this->_is_literal($this->qb_orderby[$i]['field']))
+			{
+				$this->qb_orderby[$i]['field'] = $this->protect_identifiers($this->qb_orderby[$i]['field']);
 			}
 
-			return $this->qb_orderby = "\nORDER BY ".implode(', ', $this->qb_orderby);
-		}
-		elseif (is_string($this->qb_orderby))
-		{
-			return $this->qb_orderby;
+			$this->qb_orderby[$i] = $this->qb_orderby[$i]['field'].$this->qb_orderby[$i]['direction'];
 		}
 
-		return '';
+		return "\nORDER BY ".implode(', ', $this->qb_orderby);
 	}
 
 	// --------------------------------------------------------------------
@@ -2625,7 +2636,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			'qb_cache_orderby'		=> array(),
 			'qb_cache_set'			=> array(),
 			'qb_cache_exists'		=> array(),
-			'qb_cache_no_escape'	=> array()
+			'qb_cache_no_escape'	=> array(),
+			'qb_cache_aliased_tables'	=> array()
 		));
 
 		return $this;
@@ -2676,13 +2688,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$this->qb_no_escape = $qb_no_escape;
 			}
 		}
-
-		// If we are "protecting identifiers" we need to examine the "from"
-		// portion of the query to determine if there are any aliases
-		if ($this->_protect_identifiers === TRUE && count($this->qb_cache_from) > 0)
-		{
-			$this->_track_aliases($this->qb_from);
-		}
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 257925d88..6e8aff7c6 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -250,7 +250,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -361,7 +361,7 @@ class CI_DB_cubrid_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/ibase/ibase_driver.php b/system/database/drivers/ibase/ibase_driver.php
index 106d5efac..3069d6699 100644
--- a/system/database/drivers/ibase/ibase_driver.php
+++ b/system/database/drivers/ibase/ibase_driver.php
@@ -294,7 +294,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -395,7 +395,7 @@ class CI_DB_ibase_driver extends CI_DB {
 	 */
 	protected function _insert_batch($table, $keys, $values)
 	{
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/ibase/ibase_forge.php b/system/database/drivers/ibase/ibase_forge.php
index 44bb24e68..31352f128 100644
--- a/system/database/drivers/ibase/ibase_forge.php
+++ b/system/database/drivers/ibase/ibase_forge.php
@@ -91,7 +91,7 @@ class CI_DB_ibase_forge extends CI_DB_forge {
 	 * Create database
 	 *
 	 * @param	string	$db_name
-	 * @return	string
+	 * @return	bool
 	 */
 	public function create_database($db_name)
 	{
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index f0cfb2ff9..cb89f3b3f 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -352,7 +352,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -453,7 +453,7 @@ class CI_DB_mssql_driver extends CI_DB {
 			$sql = trim(substr($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($this->qb_select) === 0)
+			if (count($this->qb_select) === 0 OR strpos(implode(',', $this->qb_select), '*') !== FALSE)
 			{
 				$select = '*'; // Inevitable
 			}
@@ -500,7 +500,7 @@ class CI_DB_mssql_driver extends CI_DB {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 8f2dd744d..71dad676e 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -337,7 +337,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -448,7 +448,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 7e4290474..b59e89494 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -210,7 +210,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 				$this->_mysqli->close();
 				$message = 'MySQLi was configured for an SSL connection, but got an unencrypted connection instead!';
 				log_message('error', $message);
-				return ($this->db->db_debug) ? $this->db->display_error($message, '', TRUE) : FALSE;
+				return ($this->db_debug) ? $this->display_error($message, '', TRUE) : FALSE;
 			}
 
 			return $this->_mysqli;
@@ -381,7 +381,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
diff --git a/system/database/drivers/mysqli/mysqli_result.php b/system/database/drivers/mysqli/mysqli_result.php
index 929c2b455..0b3d9c2b4 100644
--- a/system/database/drivers/mysqli/mysqli_result.php
+++ b/system/database/drivers/mysqli/mysqli_result.php
@@ -112,9 +112,9 @@ class CI_DB_mysqli_result extends CI_DB_result {
 		{
 			$retval[$i]			= new stdClass();
 			$retval[$i]->name		= $field_data[$i]->name;
-			$retval[$i]->type		= $field_data[$i]->type;
+			$retval[$i]->type		= static::_get_field_type($field_data[$i]->type);
 			$retval[$i]->max_length		= $field_data[$i]->max_length;
-			$retval[$i]->primary_key	= (int) ($field_data[$i]->flags & 2);
+			$retval[$i]->primary_key	= (int) ($field_data[$i]->flags & MYSQLI_PRI_KEY_FLAG);
 			$retval[$i]->default		= $field_data[$i]->def;
 		}
 
@@ -124,6 +124,60 @@ class CI_DB_mysqli_result extends CI_DB_result {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Get field type
+	 *
+	 * Extracts field type info from the bitflags returned by
+	 * mysqli_result::fetch_fields()
+	 *
+	 * @used-by	CI_DB_mysqli_result::field_data()
+	 * @param	int	$flags
+	 * @return	string
+	 */
+	private static function _get_field_type($flags)
+	{
+		static $map;
+		isset($map) OR $map = array(
+			MYSQLI_TYPE_DECIMAL     => 'decimal',
+			MYSQLI_TYPE_BIT         => 'bit',
+			MYSQLI_TYPE_TINY        => 'tinyint',
+			MYSQLI_TYPE_SHORT       => 'smallint',
+			MYSQLI_TYPE_INT24       => 'mediumint',
+			MYSQLI_TYPE_LONG        => 'int',
+			MYSQLI_TYPE_LONGLONG    => 'bigint',
+			MYSQLI_TYPE_FLOAT       => 'float',
+			MYSQLI_TYPE_DOUBLE      => 'double',
+			MYSQLI_TYPE_TIMESTAMP   => 'timestamp',
+			MYSQLI_TYPE_DATE        => 'date',
+			MYSQLI_TYPE_TIME        => 'time',
+			MYSQLI_TYPE_DATETIME    => 'datetime',
+			MYSQLI_TYPE_YEAR        => 'year',
+			MYSQLI_TYPE_NEWDATE     => 'date',
+			MYSQLI_TYPE_INTERVAL    => 'interval',
+			MYSQLI_TYPE_ENUM        => 'enum',
+			MYSQLI_TYPE_SET         => 'set',
+			MYSQLI_TYPE_TINY_BLOB   => 'tinyblob',
+			MYSQLI_TYPE_MEDIUM_BLOB => 'mediumblob',
+			MYSQLI_TYPE_BLOB        => 'blob',
+			MYSQLI_TYPE_LONG_BLOB   => 'longblob',
+			MYSQLI_TYPE_STRING      => 'char',
+			MYSQLI_TYPE_VAR_STRING  => 'varchar',
+			MYSQLI_TYPE_GEOMETRY    => 'geometry'
+		);
+
+		foreach ($map as $flag => $name)
+		{
+			if ($flags & $flag)
+			{
+				return $name;
+			}
+		}
+
+		return $flags;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Free the result
 	 *
 	 * @return	void
diff --git a/system/database/drivers/mysqli/mysqli_utility.php b/system/database/drivers/mysqli/mysqli_utility.php
index 4a3dad4d1..1699b611f 100644
--- a/system/database/drivers/mysqli/mysqli_utility.php
+++ b/system/database/drivers/mysqli/mysqli_utility.php
@@ -155,9 +155,11 @@ class CI_DB_mysqli_utility extends CI_DB_utility {
 			while ($field = $query->result_id->fetch_field())
 			{
 				// Most versions of MySQL store timestamp as a string
-				$is_int[$i] = in_array(strtolower($field->type),
-							array('tinyint', 'smallint', 'mediumint', 'int', 'bigint'), //, 'timestamp'),
-							TRUE);
+				$is_int[$i] = ($field->type & MYSQLI_TYPE_TINY)
+						OR ($field->type & MYSQLI_TYPE_SHORT)
+						OR ($field->type & MYSQLI_TYPE_INT24)
+						OR ($field->type & MYSQLI_TYPE_LONG)
+						OR ($field->type & MYSQLI_TYPE_LONGLONG);
 
 				// Create a string of field names
 				$field_str .= $this->db->escape_identifiers($field->name).', ';
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index c7f033019..fb2f6b31b 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -553,7 +553,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/oci8/oci8_forge.php b/system/database/drivers/oci8/oci8_forge.php
index 867a94341..724a76df4 100644
--- a/system/database/drivers/oci8/oci8_forge.php
+++ b/system/database/drivers/oci8/oci8_forge.php
@@ -124,7 +124,7 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 				if ($alter_type === 'MODIFY' && ! empty($field[$i]['new_name']))
 				{
 					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
-						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
+						.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
 				}
 
 				$field[$i] = "\n\t".$field[$i]['_literal'];
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 9f5a86fa0..ef982fc63 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -309,14 +309,14 @@ class CI_DB_odbc_driver extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		$this->db->display_error('db_unsupported_feature');
+		$this->display_error('db_unsupported_feature');
 	}
 
 	// --------------------------------------------------------------------
@@ -340,7 +340,7 @@ class CI_DB_odbc_driver extends CI_DB_driver {
 	 */
 	public function insert_id()
 	{
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------
@@ -402,7 +402,7 @@ class CI_DB_odbc_driver extends CI_DB_driver {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index d816dcb64..6afc999c2 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -223,7 +223,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -285,7 +285,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
index 3249a1d7f..b9b86f784 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_dblib_driver.php
@@ -284,7 +284,7 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 			$sql = trim(substr($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($this->qb_select) === 0)
+			if (count($this->qb_select) === 0 OR strpos(implode(',', $this->qb_select), '*') !== FALSE)
 			{
 				$select = '*'; // Inevitable
 			}
@@ -331,7 +331,23 @@ class CI_DB_pdo_dblib_driver extends CI_DB_pdo_driver {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
+	// --------------------------------------------------------------------
+
+	/**
+	 * Database version number
+	 *
+	 * @return      string
+	 */
+	public function version()
+	{
+		if (isset($this->data_cache['version']))
+		{
+			return $this->data_cache['version'];
+		}
+
+		return $this->data_cache['version'] = $this->conn_id->query("SELECT SERVERPROPERTY('ProductVersion') AS ver")->fetchColumn(0);
+	}
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
index aa5e7d6e7..cb93f19b7 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_firebird_driver.php
@@ -274,6 +274,6 @@ class CI_DB_pdo_firebird_driver extends CI_DB_pdo_driver {
 	 */
 	protected function _insert_batch($table, $keys, $values)
 	{
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 }
diff --git a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
index 66c15dac6..64b13d827 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_mysql_driver.php
@@ -182,7 +182,7 @@ class CI_DB_pdo_mysql_driver extends CI_DB_pdo_driver {
 		{
 			$message = 'PDO_MYSQL was configured for an SSL connection, but got an unencrypted connection instead!';
 			log_message('error', $message);
-			return ($this->db->db_debug) ? $this->db->display_error($message, '', TRUE) : FALSE;
+			return ($this->db_debug) ? $this->display_error($message, '', TRUE) : FALSE;
 		}
 
 		return $pdo;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
index c8983ee56..813207b8e 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_oci_forge.php
@@ -117,7 +117,7 @@ class CI_DB_pdo_oci_forge extends CI_DB_pdo_forge {
 				if ($alter_type === 'MODIFY' && ! empty($field[$i]['new_name']))
 				{
 					$sqls[] = $sql.' RENAME COLUMN '.$this->db->escape_identifiers($field[$i]['name'])
-						.' '.$this->db->escape_identifiers($field[$i]['new_name']);
+						.' TO '.$this->db->escape_identifiers($field[$i]['new_name']);
 				}
 			}
 		}
diff --git a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
index f4a2f08f3..066dd9614 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_odbc_driver.php
@@ -161,14 +161,14 @@ class CI_DB_pdo_odbc_driver extends CI_DB_pdo_driver {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
 	 */
 	protected function _escape_str($str)
 	{
-		$this->db->display_error('db_unsupported_feature');
+		$this->display_error('db_unsupported_feature');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
index 18e399dac..b00af4ad0 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_pgsql_forge.php
@@ -168,7 +168,7 @@ class CI_DB_pdo_pgsql_forge extends CI_DB_pdo_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
index 1cf6c614d..a9fb4d14a 100644
--- a/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
+++ b/system/database/drivers/pdo/subdrivers/pdo_sqlsrv_driver.php
@@ -316,7 +316,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 			$sql = trim(substr($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($this->qb_select) === 0)
+			if (count($this->qb_select) === 0 OR strpos(implode(',', $this->qb_select), '*') !== FALSE)
 			{
 				$select = '*'; // Inevitable
 			}
@@ -363,7 +363,7 @@ class CI_DB_pdo_sqlsrv_driver extends CI_DB_pdo_driver {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 }
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index cef464af4..bcdfc060a 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -130,9 +130,9 @@ class CI_DB_postgre_driver extends CI_DB {
 		 */
 		foreach (array('connect_timeout', 'options', 'sslmode', 'service') as $key)
 		{
-			if (isset($this->$key) && is_string($this->key) && $this->key !== '')
+			if (isset($this->$key) && is_string($this->$key) && $this->$key !== '')
 			{
-				$this->dsn .= $key."='".$this->key."' ";
+				$this->dsn .= $key."='".$this->$key."' ";
 			}
 		}
 
@@ -299,7 +299,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -471,7 +471,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index f7bbf7441..cdbff4c4b 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -163,7 +163,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	 */
 	protected function _attr_type(&$attributes)
 	{
-		// Reset field lenghts for data types that don't support it
+		// Reset field lengths for data types that don't support it
 		if (isset($attributes['CONSTRAINT']) && stripos($attributes['TYPE'], 'int') !== FALSE)
 		{
 			$attributes['CONSTRAINT'] = NULL;
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index 2d78a0f8a..d131baad7 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -168,7 +168,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Platform-dependant string escape
+	 * Platform-dependent string escape
 	 *
 	 * @param	string
 	 * @return	string
@@ -291,7 +291,7 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 10aad115f..4edcc7fb8 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -358,7 +358,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Error
 	 *
 	 * Returns an array containing code and message of the last
-	 * database error that has occured.
+	 * database error that has occurred.
 	 *
 	 * @return	array
 	 */
@@ -478,7 +478,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 			$sql = trim(substr($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($this->qb_select) === 0)
+			if (count($this->qb_select) === 0 OR strpos(implode(',', $this->qb_select), '*') !== FALSE)
 			{
 				$select = '*'; // Inevitable
 			}
@@ -525,7 +525,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 			return parent::_insert_batch($table, $keys, $values);
 		}
 
-		return ($this->db->db_debug) ? $this->db->display_error('db_unsupported_feature') : FALSE;
+		return ($this->db_debug) ? $this->display_error('db_unsupported_feature') : FALSE;
 	}
 
 	// --------------------------------------------------------------------