Merge branch 'develop' of git://github.com/EllisLab/CodeIgniter into email

16 files changed, 202 insertions, 279 deletions

diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index d056bdb90..739b25187 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -295,7 +295,7 @@ abstract class CI_DB_driver {
 	 * @param	array	An array of binding data
 	 * @return	mixed
 	 */
-	public function query($sql, $binds = FALSE, $return_object = TRUE)
+	public function query($sql, $binds = FALSE, $return_object = NULL)
 	{
 		if ($sql === '')
 		{
@@ -303,6 +303,10 @@ abstract class CI_DB_driver {
 
 			return ($this->db_debug) ? $this->display_error('db_invalid_query') : FALSE;
 		}
+		elseif ( ! is_bool($return_object))
+		{
+			$return_object = ! $this->is_write_type($sql);
+		}
 
 		// Verify table prefix and replace if necessary
 		if ($this->dbprefix !== '' && $this->swap_pre !== '' && $this->dbprefix !== $this->swap_pre)
@@ -319,7 +323,7 @@ abstract class CI_DB_driver {
 		// Is query caching enabled? If the query is a "read type"
 		// we will load the caching class and return the previously
 		// cached query if it exists
-		if ($this->cache_on === TRUE && stripos($sql, 'SELECT') !== FALSE && $this->_cache_init())
+		if ($this->cache_on === TRUE && $return_object === TRUE && $this->_cache_init())
 		{
 			$this->load_rdriver();
 			if (FALSE !== ($cache = $this->CACHE->read($sql)))
@@ -328,7 +332,7 @@ abstract class CI_DB_driver {
 			}
 		}
 
-		// Save the  query for debugging
+		// Save the query for debugging
 		if ($this->save_queries === TRUE)
 		{
 			$this->queries[] = $sql;
@@ -352,7 +356,7 @@ abstract class CI_DB_driver {
 			$error = $this->error();
 
 			// Log errors
-			log_message('error', 'Query error: '.$error['message']);
+			log_message('error', 'Query error: '.$error['message'].' - Invalid query: '.$sql);
 
 			if ($this->db_debug)
 			{
@@ -381,12 +385,10 @@ abstract class CI_DB_driver {
 		// Increment the query counter
 		$this->query_count++;
 
-		// Was the query a "write" type?
-		// If so we'll simply return true
-		if ($this->is_write_type($sql) === TRUE)
+		// Will we have a result object instantiated? If not - we'll simply return TRUE
+		if ($return_object !== TRUE)
 		{
-			// If caching is enabled we'll auto-cleanup any
-			// existing files related to this particular URI
+			// If caching is enabled we'll auto-cleanup any existing files related to this particular URI
 			if ($this->cache_on === TRUE && $this->cache_autodel === TRUE && $this->_cache_init())
 			{
 				$this->CACHE->delete();
@@ -396,8 +398,6 @@ abstract class CI_DB_driver {
 		}
 
 		// Return TRUE if we don't need to create a result object
-		// Currently only the Oracle driver uses this when stored
-		// procedures are used
 		if ($return_object !== TRUE)
 		{
 			return TRUE;
@@ -1086,6 +1086,20 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Returns the SQL string operator
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	protected function _get_operator($str)
+	{
+		return preg_match('/(=|!|<|>| IS NULL| IS NOT NULL| BETWEEN)/i', $str, $match)
+			? $match[1] : FALSE;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Enables a native PHP function to be run, using a platform agnostic wrapper.
 	 *
 	 * @param	string	the function name
@@ -1267,7 +1281,7 @@ abstract class CI_DB_driver {
 			if (isset($call['file']) && strpos($call['file'], BASEPATH.'database') === FALSE)
 			{
 				// Found it - use a relative path for safety
-				$message[] = 'Filename: '.str_replace(array(BASEPATH, APPPATH), '', $call['file']);
+				$message[] = 'Filename: '.str_replace(array(APPPATH, BASEPATH), '', $call['file']);
 				$message[] = 'Line Number: '.$call['line'];
 				break;
 			}
@@ -1336,39 +1350,21 @@ abstract class CI_DB_driver {
 		// Convert tabs or multiple spaces into single spaces
 		$item = preg_replace('/\s+/', ' ', $item);
 
-		static $preg_ec = array();
-
-		if (empty($preg_ec))
+		// If the item has an alias declaration we remove it and set it aside.
+		// Note: strripos() is used in order to support spaces in table names
+		if ($offset = strripos($item, ' AS '))
 		{
-			if (is_array($this->_escape_char))
-			{
-				$preg_ec = array(preg_quote($this->_escape_char[0]), preg_quote($this->_escape_char[1]));
-			}
-			else
-			{
-				$preg_ec[0] = $preg_ec[1] = preg_quote($this->_escape_char);
-			}
+			$alias = ($protect_identifiers)
+					? substr($item, $offset, 4).$this->escape_identifiers(substr($item, $offset + 4))
+					: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
-
-		// If the item has an alias declaration we remove it and set it aside.
-		// Basically we remove everything to the right of the first space
-		preg_match('/^(('.$preg_ec[0].'[^'.$preg_ec[1].']+'.$preg_ec[1].')|([^'.$preg_ec[0].'][^\s]+))( AS)*(.+)*$/i', $item, $matches);
-
-		if (isset($matches[4]))
+		elseif ($offset = strrpos($item, ' '))
 		{
-			$item = $matches[1];
-
-			// Escape the alias, if needed
-			if ($protect_identifiers === TRUE)
-			{
-				$alias = empty($matches[5])
-					? ' '.$this->escape_identifiers(ltrim($matches[4]))
-					: $matches[4].' '.$this->escape_identifiers(ltrim($matches[5]));
-			}
-			else
-			{
-				$alias = $matches[4].$matches[5];
-			}
+			$alias = ($protect_identifiers)
+					? ' '.$this->escape_identifiers(substr($item, $offset + 1))
+					: substr($item, $offset);
+			$item = substr($item, 0, $offset);
 		}
 		else
 		{
diff --git a/system/database/DB_forge.php b/system/database/DB_forge.php
index 9b7639289..91f9d560c 100644
--- a/system/database/DB_forge.php
+++ b/system/database/DB_forge.php
@@ -231,7 +231,7 @@ abstract class CI_DB_forge {
 
 		if (($result = $this->db->query($sql)) !== FALSE && ! empty($this->db->data_cache['table_names']))
 		{
-			$this->db->data_cache['table_names'][] = $$this->db->dbprefix.$table;
+			$this->db->data_cache['table_names'][] = $this->db->dbprefix.$table;
 		}
 
 		return $result;
diff --git a/system/database/DB_query_builder.php b/system/database/DB_query_builder.php
index 488b294e4..3982885e8 100644
--- a/system/database/DB_query_builder.php
+++ b/system/database/DB_query_builder.php
@@ -324,10 +324,10 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string
 	 * @param	string	the join condition
 	 * @param	string	the type of join
-	 * @param	string	wether not to try to escape identifiers
+	 * @param	string	whether not to try to escape identifiers
 	 * @return	object
 	 */
-	public function join($table, $cond, $type = '', $escape = TRUE)
+	public function join($table, $cond, $type = '', $escape = NULL)
 	{
 		if ($type !== '')
 		{
@@ -347,6 +347,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		// in the protect_identifiers to know whether to add a table prefix
 		$this->_track_aliases($table);
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		// Split multiple conditions
 		if ($escape === TRUE && preg_match_all('/\sAND\s|\sOR\s/i', $cond, $m, PREG_SET_ORDER | PREG_OFFSET_CAPTURE))
 		{
@@ -366,12 +368,20 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 				$newcond .= $m[0][$i][0];
 			}
 
-			$cond = $newcond;
+			$cond = ' ON '.$newcond;
 		}
 		// Split apart the condition and protect the identifiers
 		elseif ($escape === TRUE && preg_match('/([\[\w\.-]+)([\W\s]+)(.+)/i', $cond, $match))
 		{
-			$cond = $this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+			$cond = ' ON '.$this->protect_identifiers($match[1]).$match[2].$this->protect_identifiers($match[3]);
+		}
+		elseif ( ! $this->_has_operator($cond))
+		{
+			$cond = ' USING ('.($escape ? $this->escape_identifiers($cond) : $cond).')';
+		}
+		else
+		{
+			$cond = ' ON '.$cond;
 		}
 
 		// Do we want to escape the table name?
@@ -381,7 +391,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		}
 
 		// Assemble the JOIN statement
-		$this->qb_join[] = $join = $type.'JOIN '.$this->protect_identifiers($table, TRUE, NULL, FALSE).' ON '.$cond;
+		$this->qb_join[] = $join = $type.'JOIN '.$table.$cond;
 
 		if ($this->qb_caching === TRUE)
 		{
@@ -405,7 +415,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function where($key, $value = NULL, $escape = TRUE)
+	public function where($key, $value = NULL, $escape = NULL)
 	{
 		return $this->_where($key, $value, 'AND ', $escape);
 	}
@@ -423,7 +433,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function or_where($key, $value = NULL, $escape = TRUE)
+	public function or_where($key, $value = NULL, $escape = NULL)
 	{
 		return $this->_where($key, $value, 'OR ', $escape);
 	}
@@ -443,23 +453,26 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
 		// If the escape value was not set will will base it on the global setting
-		$escape = $this->_protect_identifiers;
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;
+			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+				? $this->_group_get_type('')
+				: $this->_group_get_type($type);
 
-			$k = $this->_has_operator($k)
-				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
-				: $this->protect_identifiers($k, FALSE, $escape);
+			if ($escape === TRUE)
+			{
+				$k = (($op = $this->_get_operator($k)) !== FALSE)
+					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
+					: $this->escape_identifiers(trim($k));
+			}
 
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
@@ -504,9 +517,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function where_in($key = NULL, $values = NULL)
+	public function where_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values);
+		return $this->_where_in($key, $values, FALSE, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -521,9 +534,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function or_where_in($key = NULL, $values = NULL)
+	public function or_where_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, FALSE, 'OR ');
+		return $this->_where_in($key, $values, FALSE, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -538,9 +551,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function where_not_in($key = NULL, $values = NULL)
+	public function where_not_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, TRUE);
+		return $this->_where_in($key, $values, TRUE, 'AND ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -555,9 +568,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	array	The values searched on
 	 * @return	object
 	 */
-	public function or_where_not_in($key = NULL, $values = NULL)
+	public function or_where_not_in($key = NULL, $values = NULL, $escape = NULL)
 	{
-		return $this->_where_in($key, $values, TRUE, 'OR ');
+		return $this->_where_in($key, $values, TRUE, 'OR ', $escape);
 	}
 
 	// --------------------------------------------------------------------
@@ -573,20 +586,20 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string
 	 * @return	object
 	 */
-	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ')
+	protected function _where_in($key = NULL, $values = NULL, $not = FALSE, $type = 'AND ', $escape = NULL)
 	{
 		if ($key === NULL OR $values === NULL)
 		{
 			return $this;
 		}
 
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($values))
 		{
 			$values = array($values);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		$not = ($not) ? ' NOT' : '';
 
 		foreach ($values as $value)
@@ -594,8 +607,13 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$this->qb_wherein[] = $this->escape($value);
 		}
 
-		$prefix = (count($this->qb_where) === 0) ? '' : $type;
-		$this->qb_where[] = $where_in = $prefix.$this->protect_identifiers($key).$not.' IN ('.implode(', ', $this->qb_wherein).') ';
+		if ($escape === TRUE)
+		{
+			$key = $this->escape_identifiers(trim($key));
+		}
+
+		$prefix = (count($this->qb_where) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
+		$this->qb_where[] = $where_in = $prefix.$key.$not.' IN ('.implode(', ', $this->qb_wherein).') ';
 
 		if ($this->qb_caching === TRUE)
 		{
@@ -690,8 +708,6 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	protected function _like($field, $match = '', $type = 'AND ', $side = 'both', $not = '')
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($field))
 		{
 			$field = array($field => $match);
@@ -700,7 +716,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 		foreach ($field as $k => $v)
 		{
 			$k = $this->protect_identifiers($k);
-			$prefix = (count($this->qb_like) === 0) ? '' : $type;
+			$prefix = (count($this->qb_like) === 0) ? $this->_group_get_type('') : $this->_group_get_type($type);
 			$v = $this->escape_like_str($v);
 
 			if ($side === 'none')
@@ -886,7 +902,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function having($key, $value = '', $escape = TRUE)
+	public function having($key, $value = '', $escape = NULL)
 	{
 		return $this->_having($key, $value, 'AND ', $escape);
 	}
@@ -903,7 +919,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function or_having($key, $value = '', $escape = TRUE)
+	public function or_having($key, $value = '', $escape = NULL)
 	{
 		return $this->_having($key, $value, 'OR ', $escape);
 	}
@@ -921,21 +937,22 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	protected function _having($key, $value = '', $type = 'AND ', $escape = TRUE)
+	protected function _having($key, $value = '', $type = 'AND ', $escape = NULL)
 	{
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
 			$prefix = (count($this->qb_having) === 0) ? '' : $type;
 
-			if ($escape === TRUE)
-			{
-				$k = $this->protect_identifiers($k);
-			}
+			$k = $this->_has_operator($k)
+				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
+				: $this->protect_identifiers($k, FALSE, $escape);
 
 			if ( ! $this->_has_operator($k))
 			{
@@ -968,7 +985,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool	enable field name escaping
 	 * @return	object
 	 */
-	public function order_by($orderby, $direction = '', $escape = TRUE)
+	public function order_by($orderby, $direction = '', $escape = NULL)
 	{
 		if (strtolower($direction) === 'random')
 		{
@@ -980,8 +997,9 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$direction = in_array(strtoupper(trim($direction)), array('ASC', 'DESC'), TRUE) ? ' '.$direction : ' ASC';
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
-		if ((strpos($orderby, ',') !== FALSE) && $escape === TRUE)
+		if ($escape === TRUE && strpos($orderby, ',') !== FALSE)
 		{
 			$temp = array();
 			foreach (explode(',', $orderby) as $part)
@@ -1028,12 +1046,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function limit($value, $offset = NULL)
 	{
-		$this->qb_limit = (int) $value;
-
-		if ( ! empty($offset))
-		{
-			$this->qb_offset = (int) $offset;
-		}
+		is_null($value) OR $this->qb_limit = (int) $value;
+		empty($offset) OR $this->qb_offset = (int) $offset;
 
 		return $this;
 	}
@@ -1048,21 +1062,40 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 */
 	public function offset($offset)
 	{
-		$this->qb_offset = (int) $offset;
+		empty($offset) OR $this->qb_offset = (int) $offset;
 		return $this;
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * The "set" function.  Allows key/value pairs to be set for inserting or updating
+	 * Limit string
+	 *
+	 * 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)
+	{
+		return $sql.' LIMIT '.($offset ? $offset.', ' : '').$limit;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * The "set" function.
+	 *
+	 * Allows key/value pairs to be set for inserting or updating
 	 *
 	 * @param	mixed
 	 * @param	string
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set($key, $value = '', $escape = TRUE)
+	public function set($key, $value = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array($key);
 
@@ -1071,16 +1104,12 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
-			if ($escape === FALSE)
-			{
-				$this->qb_set[$this->protect_identifiers($k)] = $v;
-			}
-			else
-			{
-				$this->qb_set[$this->protect_identifiers($k, FALSE, TRUE)] = $this->escape($v);
-			}
+			$this->qb_set[$this->protect_identifiers($k, FALSE, $escape)] = ($escape)
+				? $this->escape($v) : $v;
 		}
 
 		return $this;
@@ -1189,7 +1218,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	string	the offset clause
 	 * @return	object
 	 */
-	public function get_where($table = '', $where = null, $limit = null, $offset = null)
+	public function get_where($table = '', $where = NULL, $limit = NULL, $offset = NULL)
 	{
 		if ($table !== '')
 		{
@@ -1286,7 +1315,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set_insert_batch($key, $value = '', $escape = TRUE)
+	public function set_insert_batch($key, $value = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array_batch($key);
 
@@ -1295,6 +1324,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			$key = array($key => $value);
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		$keys = array_keys($this->_object_to_array(current($key)));
 		sort($keys);
 
@@ -1326,7 +1357,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 
 		foreach ($keys as $k)
 		{
-			$this->qb_keys[] = $this->protect_identifiers($k);
+			$this->qb_keys[] = $this->protect_identifiers($k, FALSE, $escape);
 		}
 
 		return $this;
@@ -1725,7 +1756,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 	 * @param	bool
 	 * @return	object
 	 */
-	public function set_update_batch($key, $index = '', $escape = TRUE)
+	public function set_update_batch($key, $index = '', $escape = NULL)
 	{
 		$key = $this->_object_to_array_batch($key);
 
@@ -1734,6 +1765,8 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 			// @todo error
 		}
 
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
+
 		foreach ($key as $k => $v)
 		{
 			$index_set = FALSE;
@@ -1745,7 +1778,7 @@ abstract class CI_DB_query_builder extends CI_DB_driver {
 					$index_set = TRUE;
 				}
 
-				$clean[$this->protect_identifiers($k2)] = ($escape === FALSE) ? $v2 : $this->escape($v2);
+				$clean[$this->protect_identifiers($k2, FALSE, $escape)] = ($escape === FALSE) ? $v2 : $this->escape($v2);
 			}
 
 			if ($index_set === FALSE)
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 6b67b7546..7496ee42f 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -437,23 +437,6 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 5a03607ee..38d30962c 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -235,7 +235,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 * @param	int	$inc_by
 	 * @return	int
 	 */
-	public function insert_id($generator_name, $inc_by=0)
+	public function insert_id($generator_name, $inc_by = 0)
 	{
 		//If a generator hasn't been used before it will return 0
 		return ibase_gen_id('"'.$generator_name.'"', $inc_by);
@@ -257,7 +257,8 @@ class CI_DB_interbase_driver extends CI_DB {
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql.' AND "RDB$RELATION_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' AND "RDB$RELATION_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -275,7 +276,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SELECT "RDB$FIELD_NAME" FROM "RDB$RELATION_FIELDS" WHERE "RDB$RELATION_NAME" = \''.$this->escape_str($table)."'";
+		return 'SELECT "RDB$FIELD_NAME" FROM "RDB$RELATION_FIELDS" WHERE "RDB$RELATION_NAME" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -290,10 +291,7 @@ class CI_DB_interbase_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		// Need to find a more efficient way to do this
-		// but Interbase/Firebird seems to lack the
-		// limit clause
-		return 'SELECT * FROM '.$table;
+		return $this->_limit('SELECT * FROM '.$this->protect_identifiers($table), 1, NULL);
 	}
 
 	// --------------------------------------------------------------------
@@ -361,7 +359,6 @@ class CI_DB_interbase_driver extends CI_DB {
 			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '');
 	}
 
-
 	// --------------------------------------------------------------------
 
 	/**
@@ -421,12 +418,12 @@ class CI_DB_interbase_driver extends CI_DB {
 		if (stripos($this->version(), 'firebird') !== FALSE)
 		{
 			$select = 'FIRST '. (int) $limit
-				.($offset > 0 ? ' SKIP '. (int) $offset : '');
+				.($offset ? ' SKIP '. (int) $offset : '');
 		}
 		else
 		{
 			$select = 'ROWS '
-				.($offset > 0 ? (int) $offset.' TO '.($limit + $offset) : (int) $limit);
+				.($offset ? (int) $offset.' TO '.($limit + $offset) : (int) $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 47dc55844..7634be2bb 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -124,7 +124,7 @@ class CI_DB_mssql_driver extends CI_DB {
 		// 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;
+		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
 		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
 
 		return $conn_id;
@@ -288,7 +288,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	public function insert_id()
 	{
-		$query = (self::_parse_major_version($this->version()) > 7)
+		$query = version_compare($this->version(), '8', '>=')
 			? 'SELECT SCOPE_IDENTITY() AS last_id'
 			: 'SELECT @@IDENTITY AS last_id';
 
@@ -300,23 +300,6 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Parse major version
-	 *
-	 * Grabs the major version number from the
-	 * database server version string passed in.
-	 *
-	 * @param	string	$version
-	 * @return	int	major version number
-	 */
-	protected function _parse_major_version($version)
-	{
-		preg_match('/([0-9]+)\.([0-9]+)\.([0-9]+)/', $version, $ver_info);
-		return $ver_info[1]; // return the major version b/c that's all we're interested in.
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Version number query string
 	 *
 	 * @return	string
@@ -338,16 +321,17 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
+		$sql = 'SELECT '.$this->escape_identifiers('name')
+			.' FROM '.$this->escape_identifiers('sysobjects')
+			.' WHERE '.$this->escape_identifiers('type')." = 'U'";
 
-		// for future compatibility
 		if ($prefix_limit !== FALSE AND $this->dbprefix !== '')
 		{
-			//$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
-			return FALSE; // not currently supported
+			$sql .= ' AND '.$this->escape_identifiers('name')." LIKE '".$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
-		return $sql;
+		return $sql.' ORDER BY '.$this->escape_identifiers('name');
 	}
 
 	// --------------------------------------------------------------------
@@ -377,7 +361,7 @@ class CI_DB_mssql_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT TOP 1 * FROM '.$table;
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 8938d22b5..d11f015a6 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -64,6 +64,12 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	public $delete_hack = TRUE;
 
+	/**
+	 * Constructor
+	 *
+	 * @param	array
+	 * @return	void
+	 */
 	public function __construct($params)
 	{
 		parent::__construct($params);
@@ -74,6 +80,8 @@ class CI_DB_mysql_driver extends CI_DB {
 		}
 	}
 
+	// --------------------------------------------------------------------
+
 	/**
 	 * Non-persistent database connection
 	 *
@@ -335,7 +343,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SHOW TABLES FROM '.$this->_escape_char.$this->database.$this->_escape_char;
+		$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
@@ -355,7 +363,7 @@ class CI_DB_mysql_driver extends CI_DB {
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	public function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
 		return 'SHOW COLUMNS FROM '.$this->protect_identifiers($table, TRUE, NULL, FALSE);
 	}
@@ -453,23 +461,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.' LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/mysql/mysql_forge.php b/system/database/drivers/mysql/mysql_forge.php
index d22454d84..2ac75bad2 100644
--- a/system/database/drivers/mysql/mysql_forge.php
+++ b/system/database/drivers/mysql/mysql_forge.php
@@ -62,7 +62,7 @@ class CI_DB_mysql_forge extends CI_DB_forge {
 
 				$sql .= "\n\t".$this->db->escape_identifiers($field);
 
-				empty($attributes['NAME']) OR ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
+				empty($attributes['NAME']) OR $sql .= ' '.$this->db->escape_identifiers($attributes['NAME']).' ';
 
 				if ( ! empty($attributes['TYPE']))
 				{
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index d3fb77a22..d1581bf1a 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -335,7 +335,7 @@ class CI_DB_mysqli_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SHOW TABLES FROM '.$this->_escape_char.$this->database.$this->_escape_char;
+		$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
@@ -455,24 +455,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.' LIMIT '.$limit
-			.($offset > 0 ? ' OFFSET '.$offset : '');
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index e78091614..67bb0403b 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -66,6 +66,8 @@ class CI_DB_oci8_driver extends CI_DB {
 	protected $_count_string = 'SELECT COUNT(1) AS ';
 	protected $_random_keyword = ' ASC'; // not currently supported
 
+	protected $_reserved_identifiers = array('*', 'rownum');
+
 	// Set "auto commit" by default
 	public $commit_mode = OCI_COMMIT_ON_SUCCESS;
 
@@ -464,11 +466,12 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = 'SELECT TABLE_NAME FROM ALL_TABLES';
+		$sql = 'SELECT "TABLE_NAME" FROM "ALL_TABLES"';
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql." WHERE TABLE_NAME LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' WHERE "TABLE_NAME" LIKE \''.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -486,7 +489,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SELECT COLUMN_NAME FROM all_tab_columns WHERE table_name = \''.$table.'\'';
+		return 'SELECT "COLUMN_NAME" FROM "all_tab_columns" WHERE "TABLE_NAME" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -501,7 +504,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT * FROM '.$table.' WHERE rownum = 1';
+		return 'SELECT * FROM '.$this->protect_identifiers($table).' WHERE rownum = 1';
 	}
 
 	// --------------------------------------------------------------------
@@ -634,7 +637,7 @@ class CI_DB_oci8_driver extends CI_DB {
 	{
 		$this->limit_used = TRUE;
 		return 'SELECT * FROM (SELECT inner_query.*, rownum rnum FROM ('.$sql.') inner_query WHERE rownum < '.($offset + $limit).')'
-			.($offset !== 0 ? ' WHERE rnum >= '.$offset : '');
+			.($offset ? ' WHERE rnum >= '.$offset : '');
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 222c311c0..bd5759289 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -331,23 +331,6 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index e25013a52..a3ad46900 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -599,19 +599,12 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	protected function _limit($sql, $limit, $offset)
 	{
-		if ($this->pdodriver === 'cubrid' OR $this->pdodriver === 'sqlite')
+		if ($this->pdodriver === 'pgsql')
 		{
-			$offset = ($offset == 0) ? '' : $offset.', ';
-
-			return $sql.'LIMIT '.$offset.$limit;
+			return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
 		}
-		else
-		{
-			$sql .= 'LIMIT '.$limit;
-			$sql .= ($offset > 0) ? ' OFFSET '.$offset : '';
 
-			return $sql;
-		}
+		return $sql.' LIMIT '.($offset ? $offset.', ' : '').$limit;
 	}
 
 }
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index ad9ac9000..e73122bc7 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -399,11 +399,13 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'";
+		$sql = 'SELECT "table_name" FROM "information_schema"."tables" WHERE "table_schema" = \'public\'';
 
 		if ($prefix_limit !== FALSE && $this->dbprefix !== '')
 		{
-			return $sql." AND table_name LIKE '".$this->escape_like_str($this->dbprefix)."%' ".sprintf($this->_like_escape_str, $this->_like_escape_chr);
+			return $sql.' AND "table_name" LIKE \''
+				.$this->escape_like_str($this->dbprefix)."%' "
+				.sprintf($this->_like_escape_str, $this->_like_escape_chr);
 		}
 
 		return $sql;
@@ -421,7 +423,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return "SELECT column_name FROM information_schema.columns WHERE table_name = '".$table."'";
+		return 'SELECT "column_name" FROM "information_schema"."columns" WHERE "table_name" = '.$this->escape($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -580,7 +582,7 @@ class CI_DB_postgre_driver extends CI_DB {
 	 */
 	protected function _limit($sql, $limit, $offset)
 	{
-		return $sql.' LIMIT '.$limit.($offset == 0 ? '' : ' OFFSET '.$offset);
+		return $sql.' LIMIT '.$limit.($offset ? ' OFFSET '.$offset : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -593,31 +595,31 @@ class CI_DB_postgre_driver extends CI_DB {
 	 * @param	mixed
 	 * @param	mixed
 	 * @param	string
+	 * @param	mixed
 	 * @return	object
-	 *
 	 */
 	protected function _where($key, $value = NULL, $type = 'AND ', $escape = NULL)
 	{
-		$type = $this->_group_get_type($type);
-
 		if ( ! is_array($key))
 		{
 			$key = array($key => $value);
 		}
 
 		// If the escape value was not set will will base it on the global setting
-		if ( ! is_bool($escape))
-		{
-			$escape = $this->_protect_identifiers;
-		}
+		is_bool($escape) OR $escape = $this->_protect_identifiers;
 
 		foreach ($key as $k => $v)
 		{
-			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0) ? '' : $type;
+			$prefix = (count($this->qb_where) === 0 && count($this->qb_cache_where) === 0)
+				? $this->_group_get_type('')
+				: $this->_group_get_type($type);
 
-			$k = $this->_has_operator($k)
-				? $this->protect_identifiers(substr($k, 0, strpos(rtrim($k), ' ')), FALSE, $escape).strchr(rtrim($k), ' ')
-				: $this->protect_identifiers($k, FALSE, $escape);
+			if ($escape === TRUE)
+			{
+				$k = (($op = $this->_get_operator($k)) !== FALSE)
+					? $this->escape_identifiers(trim(substr($k, 0, strpos($k, $op)))).' '.strstr($k, $op)
+					: $this->escape_identifiers(trim($k));
+			}
 
 			if (is_null($v) && ! $this->_has_operator($k))
 			{
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 3305f6030..87be7a54a 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -360,23 +360,6 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index bed61891b..1c6533f22 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -353,23 +353,6 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Limit string
-	 *
-	 * 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)
-	{
-		return $sql.' LIMIT '.($offset ? $offset.',' : '').$limit;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Close DB Connection
 	 *
 	 * @return	void
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index 825c02452..4fdc4aae0 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -91,7 +91,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 		// 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;
+		$this->_quoted_identifier = empty($query) ? FALSE : (bool) $query['qi'];
 		$this->_escape_char = ($this->_quoted_identifier) ? '"' : array('[', ']');
 
 		return $conn_id;
@@ -284,7 +284,17 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	protected function _list_tables($prefix_limit = FALSE)
 	{
-		return "SELECT name FROM sysobjects WHERE type = 'U' ORDER BY name";
+		$sql = 'SELECT '.$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');
 	}
 
 	// --------------------------------------------------------------------
@@ -314,7 +324,7 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 */
 	protected function _field_data($table)
 	{
-		return 'SELECT TOP 1 * FROM '.$table;
+		return 'SELECT TOP 1 * FROM '.$this->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------