Merge upstream branch

25 files changed, 223 insertions, 1178 deletions

diff --git a/system/database/DB_active_rec.php b/system/database/DB_active_rec.php
index b324226ab..a19f9bedd 100644
--- a/system/database/DB_active_rec.php
+++ b/system/database/DB_active_rec.php
@@ -1219,6 +1219,23 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Insert_batch statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data.
+	 *
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	protected function _insert_batch($table, $keys, $values)
+	{
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * The "set_insert_batch" function.  Allows key/value pairs to be set for batch inserts
 	 *
 	 * @param	mixed
@@ -1341,6 +1358,23 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Insert statement
+	 *
+	 * Generates a platform-specific insert string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	protected function _insert($table, $keys, $values)
+	{
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Validate Insert
 	 *
 	 * This method is used by both insert() and get_compiled_insert() to
@@ -1413,6 +1447,23 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Replace statement
+	 *
+	 * Generates a platform-specific replace string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the insert keys
+	 * @param	array	the insert values
+	 * @return	string
+	 */
+	protected function _replace($table, $keys, $values)
+	{
+		return 'REPLACE INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Get UPDATE query string
 	 *
 	 * Compiles an update query and returns the sql
@@ -1486,6 +1537,33 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Update statement
+	 *
+	 * Generates a platform-specific update string from the supplied data
+	 *
+	 * @param	string	the table name
+	 * @param	array	the update data
+	 * @param	array	the where clause
+	 * @param	array	the orderby clause
+	 * @param	array	the limit clause
+	 * @return	string
+	 */
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	{
+		foreach ($values as $key => $val)
+		{
+			$valstr[] = $key.' = '.$val;
+		}
+
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
+			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
+			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
+			.($limit ? ' LIMIT '.$limit : '');
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Validate Update
 	 *
 	 * This method is used by both update() and get_compiled_update() to
@@ -1684,6 +1762,24 @@ abstract class CI_DB_active_record extends CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Truncate statement
+	 *
+	 * Generates a platform-specific truncate string from the supplied data
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
+	 *
+	 * @param	string	the table name
+	 * @return	string
+	 */
+	protected function _truncate($table)
+	{
+		return 'TRUNCATE '.$table;
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Get DELETE query string
 	 *
 	 * Compiles a delete query string and returns the sql
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index dea705054..8b030af77 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -901,6 +901,43 @@ abstract class CI_DB_driver {
 	// --------------------------------------------------------------------
 
 	/**
+	 * Escape the SQL Identifiers
+	 *
+	 * This function escapes column and table names
+	 *
+	 * @param	string
+	 * @return	string
+	 */
+	public function escape_identifiers($item)
+	{
+		if ($this->_escape_char == '')
+		{
+			return $item;
+		}
+
+		foreach ($this->_reserved_identifiers as $id)
+		{
+			if (strpos($item, '.'.$id) !== FALSE)
+			{
+				$item = str_replace('.', $this->_escape_char.'.', $item);
+
+				// remove duplicates if the user already included the escape
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
+			}
+		}
+
+		if (strpos($item, '.') !== FALSE)
+		{
+			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
+		}
+
+		// remove duplicates if the user already included the escape
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
 	 * Generate an insert string
 	 *
 	 * @param	string	the table upon which the query will be performed
@@ -913,7 +950,7 @@ abstract class CI_DB_driver {
 
 		foreach ($data as $key => $val)
 		{
-			$fields[] = $this->_escape_identifiers($key);
+			$fields[] = $this->escape_identifiers($key);
 			$values[] = $this->escape($val);
 		}
 
@@ -1254,7 +1291,7 @@ abstract class CI_DB_driver {
 					{
 						if ( ! in_array($val, $this->_reserved_identifiers))
 						{
-							$parts[$key] = $this->_escape_identifiers($val);
+							$parts[$key] = $this->escape_identifiers($val);
 						}
 					}
 
@@ -1311,7 +1348,7 @@ abstract class CI_DB_driver {
 
 			if ($protect_identifiers === TRUE)
 			{
-				$item = $this->_escape_identifiers($item);
+				$item = $this->escape_identifiers($item);
 			}
 
 			return $item.$alias;
@@ -1334,7 +1371,7 @@ abstract class CI_DB_driver {
 
 		if ($protect_identifiers === TRUE && ! in_array($item, $this->_reserved_identifiers))
 		{
-			$item = $this->_escape_identifiers($item);
+			$item = $this->escape_identifiers($item);
 		}
 
 		return $item.$alias;
diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 0f9c427e6..74d1a850a 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -435,45 +435,6 @@ class CI_DB_cubrid_driver extends CI_DB {
 		return array('code' => cubrid_errno($this->conn_id), 'message' => cubrid_error($this->conn_id));
 	}
 
-	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
 	// --------------------------------------------------------------------
 
 	/**
@@ -498,94 +459,6 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return "INSERT INTO ".$table." (\"".implode('", "', $keys)."\") VALUES (".implode(', ', $values).")";
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
-	 * Replace statement
-	 *
-	 * Generates a platform-specific replace string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _replace($table, $keys, $values)
-	{
-		return "REPLACE INTO ".$table." (\"".implode('", "', $keys)."\") VALUES (".implode(', ', $values).")";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert_batch($table, $keys, $values)
-	{
-		return "INSERT INTO ".$table." (\"".implode('", "', $keys)."\") VALUES ".implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = sprintf('"%s" = %s', $key, $val);
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
@@ -637,23 +510,6 @@ class CI_DB_cubrid_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return "TRUNCATE ".$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
diff --git a/system/database/drivers/cubrid/cubrid_forge.php b/system/database/drivers/cubrid/cubrid_forge.php
index bbda484c4..f83dc97f4 100644
--- a/system/database/drivers/cubrid/cubrid_forge.php
+++ b/system/database/drivers/cubrid/cubrid_forge.php
@@ -184,9 +184,7 @@ class CI_DB_cubrid_forge extends CI_DB_forge {
 			// As of version 8.4.0 CUBRID does not support this SQL syntax.
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
-
-		$sql .= $this->_process_fields($fields);
+		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields);
 
 		// If there is a PK defined
 		if (count($primary_keys) > 0)
@@ -230,7 +228,7 @@ class CI_DB_cubrid_forge extends CI_DB_forge {
 	 */
 	public function _drop_table($table)
 	{
-		return "DROP TABLE IF EXISTS ".$this->db->_escape_identifiers($table);
+		return 'DROP TABLE IF EXISTS '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/interbase/interbase_driver.php b/system/database/drivers/interbase/interbase_driver.php
index 6d3346292..88638a21a 100644
--- a/system/database/drivers/interbase/interbase_driver.php
+++ b/system/database/drivers/interbase/interbase_driver.php
@@ -343,38 +343,6 @@ class CI_DB_interbase_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This public function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	protected function _escape_identifiers($item)
-	{
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This public function implicitly groups FROM tables so there is no confusion
@@ -397,23 +365,6 @@ class CI_DB_interbase_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
@@ -446,15 +397,16 @@ class CI_DB_interbase_driver extends CI_DB {
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This public function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return $this->_delete($table);
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 81af6cd72..ae3b843ee 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -404,47 +404,6 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -466,70 +425,19 @@ class CI_DB_mssql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
-	}
-
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return "TRUNCATE ".$table;
+		return 'TRUNCATE TABLE '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index 2e3e314ed..d787b3764 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -68,7 +68,7 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 	 */
 	public function _drop_table($table)
 	{
-		return "DROP TABLE ".$this->db->_escape_identifiers($table);
+		return 'DROP TABLE '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -92,7 +92,7 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
 		foreach ($fields as $field => $attributes)
diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index bef4111c3..28020d3e6 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -439,43 +439,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -497,59 +460,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
-	 * Replace statement
-	 *
-	 * Generates a platform-specific replace string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _replace($table, $keys, $values)
-	{
-		return 'REPLACE INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert_batch($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
@@ -624,23 +534,6 @@ class CI_DB_mysql_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'TRUNCATE '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 47b0449d6..50e213641 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -439,43 +439,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -497,85 +460,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert_batch($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-
-	/**
-	 * Replace statement
-	 *
-	 * Generates a platform-specific replace string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _replace($table, $keys, $values)
-	{
-		return 'REPLACE INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
-			.( ! $limit ? '' : ' LIMIT '.$limit);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update_Batch statement
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
@@ -619,23 +503,6 @@ class CI_DB_mysqli_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'TRUNCATE '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
diff --git a/system/database/drivers/mysqli/mysqli_forge.php b/system/database/drivers/mysqli/mysqli_forge.php
index a1caf5cfb..4b6939e2a 100644
--- a/system/database/drivers/mysqli/mysqli_forge.php
+++ b/system/database/drivers/mysqli/mysqli_forge.php
@@ -148,7 +148,7 @@ class CI_DB_mysqli_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table).' ('.$this->_process_fields($fields);
+		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields);
 
 		if (count($primary_keys) > 0)
 		{
@@ -187,7 +187,7 @@ class CI_DB_mysqli_forge extends CI_DB_forge {
 	 */
 	public function _drop_table($table)
 	{
-		return 'DROP TABLE IF EXISTS '.$this->db->_escape_identifiers($table);
+		return 'DROP TABLE IF EXISTS '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/mysqli/mysqli_utility.php b/system/database/drivers/mysqli/mysqli_utility.php
index 4d7002e78..cb3f86b8b 100644
--- a/system/database/drivers/mysqli/mysqli_utility.php
+++ b/system/database/drivers/mysqli/mysqli_utility.php
@@ -56,7 +56,7 @@ class CI_DB_mysqli_utility extends CI_DB_utility {
 	 */
 	public function _optimize_table($table)
 	{
-		return 'OPTIMIZE TABLE '.$this->db->_escape_identifiers($table);
+		return 'OPTIMIZE TABLE '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -71,7 +71,7 @@ class CI_DB_mysqli_utility extends CI_DB_utility {
 	 */
 	public function _repair_table($table)
 	{
-		return 'REPAIR TABLE '.$this->db->_escape_identifiers($table);
+		return 'REPAIR TABLE '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 0a96f3f6d..6e225ee1f 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -567,43 +567,6 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -620,23 +583,6 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Insert_batch statement
 	 *
 	 * Generates a platform-specific insert string from the supplied data
@@ -653,7 +599,7 @@ class CI_DB_oci8_driver extends CI_DB {
 
 		for ($i = 0, $c = count($values); $i < $c; $i++)
 		{
-			$sql .= '	INTO '.$table.' ('.$keys.') VALUES '.$values[$i].'\n';
+			$sql .= '	INTO '.$table.' ('.$keys.') VALUES '.$values[$i]."\n";
 		}
 
 		return $sql.'SELECT * FROM dual';
@@ -662,38 +608,12 @@ class CI_DB_oci8_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
-			.( ! $limit ? '' : ' LIMIT '.$limit);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
diff --git a/system/database/drivers/oci8/oci8_forge.php b/system/database/drivers/oci8/oci8_forge.php
index 4b2eccae5..033e618e7 100644
--- a/system/database/drivers/oci8/oci8_forge.php
+++ b/system/database/drivers/oci8/oci8_forge.php
@@ -81,7 +81,7 @@ class CI_DB_oci8_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table).' (';
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
 		foreach ($fields as $field => $attributes)
diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index ed901bd81..d1a5f774b 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -343,47 +343,6 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -405,70 +364,19 @@ class CI_DB_odbc_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
-	}
-
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return $this->_delete($table);
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/odbc/odbc_forge.php b/system/database/drivers/odbc/odbc_forge.php
index 486a8dd7f..afdd6dec2 100644
--- a/system/database/drivers/odbc/odbc_forge.php
+++ b/system/database/drivers/odbc/odbc_forge.php
@@ -91,7 +91,7 @@ class CI_DB_odbc_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
 		foreach ($fields as $field => $attributes)
diff --git a/system/database/drivers/pdo/pdo_driver.php b/system/database/drivers/pdo/pdo_driver.php
index a9bed367e..919bb9c00 100644
--- a/system/database/drivers/pdo/pdo_driver.php
+++ b/system/database/drivers/pdo/pdo_driver.php
@@ -46,8 +46,8 @@ class CI_DB_pdo_driver extends CI_DB {
 	protected $_escape_char = '';
 
 	// clause and character used for LIKE escape sequences
-	protected $_like_escape_str;
-	protected $_like_escape_chr;
+	protected $_like_escape_str = " ESCAPE '%s' ";
+	protected $_like_escape_chr = '!';
 
 	/**
 	 * The syntax to count rows is slightly different across different
@@ -81,18 +81,17 @@ class CI_DB_pdo_driver extends CI_DB {
 		// this one depends on the driver being used
 		if ($this->pdodriver == 'mysql')
 		{
+			$this->_escape_char = '`';
 			$this->_like_escape_str = '';
 			$this->_like_escape_chr = '';
 		}
 		elseif ($this->pdodriver == 'odbc')
 		{
 			$this->_like_escape_str = " {escape '%s'} ";
-			$this->_like_escape_chr = '!';
 		}
-		else
+		elseif ( ! in_array($this->pdodriver, array('sqlsrv', 'mssql', 'dblib', 'sybase')))
 		{
-			$this->_like_escape_str = " ESCAPE '%s' ";
-			$this->_like_escape_chr = '!';
+			$this->_escape_char = '"';
 		}
 
 		$this->trans_enabled = FALSE;
@@ -268,8 +267,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	protected function _execute($sql)
 	{
-		$sql = $this->_prep_query($sql);
-
 		$result_id = $this->conn_id->query($sql);
 
 		if (is_object($result_id))
@@ -287,32 +284,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Prep the query
-	 *
-	 * If needed, each database adapter can prep the query string
-	 *
-	 * @param	string	an SQL query
-	 * @return	string
-	 */
-	protected function _prep_query($sql)
-	{
-		if ($this->pdodriver === 'pgsql')
-		{
-			// Change the backtick(s) for Postgre
-			$sql = str_replace('`', '"', $sql);
-		}
-		elseif ($this->pdodriver === 'sqlite')
-		{
-			// Change the backtick(s) for SQLite
-			$sql = str_replace('`', '', $sql);
-		}
-
-		return $sql;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Begin Transaction
 	 *
 	 * @return	bool
@@ -516,7 +487,7 @@ class CI_DB_pdo_driver extends CI_DB {
 		}
 		else
 		{
-			$sql = "SHOW TABLES FROM `".$this->database."`";
+			$sql = 'SHOW TABLES FROM '.$this->escape_identifiers($this->database);
 		}
 
 		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
@@ -539,7 +510,7 @@ class CI_DB_pdo_driver extends CI_DB {
 	 */
 	protected function _list_columns($table = '')
 	{
-		return 'SHOW COLUMNS FROM '.$this->_from_tables($table);
+		return 'SHOW COLUMNS FROM '.$this->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -557,20 +528,20 @@ class CI_DB_pdo_driver extends CI_DB {
 		if ($this->pdodriver == 'mysql' or $this->pdodriver == 'pgsql')
 		{
 			// Analog function for mysql and postgre
-			return 'SELECT * FROM '.$this->_from_tables($table).' LIMIT 1';
+			return 'SELECT * FROM '.$this->escape_identifiers($table).' LIMIT 1';
 		}
 		elseif ($this->pdodriver == 'oci')
 		{
 			// Analog function for oci
-			return 'SELECT * FROM '.$this->_from_tables($table).' WHERE ROWNUM <= 1';
+			return 'SELECT * FROM '.$this->escape_identifiers($table).' WHERE ROWNUM <= 1';
 		}
 		elseif ($this->pdodriver == 'sqlite')
 		{
 			// Analog function for sqlite
-			return 'PRAGMA table_info('.$this->_from_tables($table).')';
+			return 'PRAGMA table_info('.$this->escape_identifiers($table).')';
 		}
 
-		return 'SELECT TOP 1 FROM '.$this->_from_tables($table);
+		return 'SELECT TOP 1 FROM '.$this->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -605,48 +576,6 @@ class CI_DB_pdo_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str  = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-			$str .= $this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -662,72 +591,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			$tables = array($tables);
 		}
 
-		return (count($tables) == 1) ? '`'.$tables[0].'`' : '('.implode(', ', $tables).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$this->_from_tables($table).' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert_batch($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$this->_from_tables($table).' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit   = ( ! $limit) ? '' : ' LIMIT '.$limit;
-		$orderby = (count($orderby) >= 1) ? ' ORDER BY '.implode(', ', $orderby) : '';
-
-		$sql  = 'UPDATE '.$this->_from_tables($table).' SET '.implode(', ', $valstr);
-		$sql .= ($where != '' && count($where) >= 1) ? ' WHERE '.implode(' ', $where) : '';
-		$sql .= $orderby.$limit;
-
-		return $sql;
+		return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -760,7 +624,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			}
 		}
 
-		$sql   = 'UPDATE '.$this->_from_tables($table).' SET ';
+		$sql   = 'UPDATE '.$table.' SET ';
 		$cases = '';
 
 		foreach ($final as $k => $v)
@@ -787,15 +651,16 @@ class CI_DB_pdo_driver extends CI_DB {
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return $this->_delete($table);
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
@@ -829,7 +694,7 @@ class CI_DB_pdo_driver extends CI_DB {
 
 		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
 
-		return 'DELETE FROM '.$this->_from_tables($table).$conditions.$limit;
+		return 'DELETE FROM '.$table.$conditions.$limit;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/pdo/pdo_forge.php b/system/database/drivers/pdo/pdo_forge.php
index 6bff3542f..9635e4c9a 100644
--- a/system/database/drivers/pdo/pdo_forge.php
+++ b/system/database/drivers/pdo/pdo_forge.php
@@ -91,10 +91,10 @@ class CI_DB_pdo_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= '`'.$this->db->_escape_identifiers($table).'` (';
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index d92110e3b..a5e296718 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -465,43 +465,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -523,40 +486,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Insert_batch statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param   string  the table name
-	 * @param   array   the insert keys
-	 * @param   array   the insert values
-	 * @return  string
-	 */
-	protected function _insert_batch($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
@@ -584,23 +513,6 @@ class CI_DB_postgre_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Truncate statement
-	 *
-	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
-	 *
-	 * @param	string	the table name
-	 * @return	string
-	 */
-	protected function _truncate($table)
-	{
-		return 'TRUNCATE '.$table;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Delete statement
 	 *
 	 * Generates a platform-specific delete string from the supplied data
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index ab9c95b89..0662ce9e8 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -172,7 +172,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 			}
 		}
 
-		$sql .= $this->db->protect_identifiers($table).' ('.$this->_process_fields($fields, $primary_keys);
+		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields, $primary_keys);
 
 		if (count($primary_keys) > 0)
 		{
@@ -220,7 +220,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	 */
 	public function _drop_table($table)
 	{
-		return 'DROP TABLE IF EXISTS '.$this->db->protect_identifiers($table).' CASCADE';
+		return 'DROP TABLE IF EXISTS '.$this->db->escape_identifiers($table).' CASCADE';
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index ef543c9b5..3a986d0a8 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -366,47 +366,6 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -428,70 +387,36 @@ class CI_DB_sqlite_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
+	 * Replace statement
 	 *
-	 * Generates a platform-specific insert string from the supplied data
+	 * Generates a platform-specific replace string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	protected function _insert($table, $keys, $values)
+	protected function _replace($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (".implode(', ', $keys).") VALUES (".implode(', ', $values).")";
+		return 'INSERT OR '.parent::_replace($table, $keys, $values);
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key." = ".$val;
-		}
-
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
-	}
-
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this function maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return $this->_delete($table);
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlite/sqlite_forge.php b/system/database/drivers/sqlite/sqlite_forge.php
index 068a556ed..a62e8d9ae 100644
--- a/system/database/drivers/sqlite/sqlite_forge.php
+++ b/system/database/drivers/sqlite/sqlite_forge.php
@@ -90,10 +90,10 @@ class CI_DB_sqlite_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)."(";
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
diff --git a/system/database/drivers/sqlite3/sqlite3_driver.php b/system/database/drivers/sqlite3/sqlite3_driver.php
index de3705296..12354e1bc 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -2,7 +2,7 @@
 /**
  * CodeIgniter
  *
- * An open source application development framework for PHP 5.1.6 or newer
+ * An open source application development framework for PHP 5.2.4 or newer
  *
  * NOTICE OF LICENSE
  *
@@ -16,12 +16,12 @@
  * through the world wide web, please send an email to
  * licensing@ellislab.com so we can send you a copy immediately.
  *
- * @package	CodeIgniter
- * @author	EllisLab Dev Team
+ * @package		CodeIgniter
+ * @author		EllisLab Dev Team
  * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
- * @license	http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
- * @link	http://codeigniter.com
- * @since	Version 1.0
+ * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
+ * @link		http://codeigniter.com
+ * @since		Version 1.0
  * @filesource
  */
 
@@ -32,11 +32,12 @@
  * creates dynamically based on whether the active record
  * class is being used or not.
  *
- * @package	CodeIgniter
+ * @package		CodeIgniter
  * @subpackage	Drivers
  * @category	Database
- * @author	Andrey Andreev
- * @link	http://codeigniter.com/user_guide/database/
+ * @author		Andrey Andreev
+ * @link		http://codeigniter.com/user_guide/database/
+ * @since		Version 3.0
  */
 class CI_DB_sqlite3_driver extends CI_DB {
 
@@ -341,43 +342,6 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		if ($this->_escape_char == '')
-		{
-			return $item;
-		}
-
-		foreach ($this->_reserved_identifiers as $id)
-		{
-			if (strpos($item, '.'.$id) !== FALSE)
-			{
-				$item = str_replace('.', $this->_escape_char.'.', $item);
-
-				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
-			}
-		}
-
-		if (strpos($item, '.') !== FALSE)
-		{
-			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
-		}
-
-		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -399,45 +363,18 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
+	 * Replace statement
 	 *
-	 * Generates a platform-specific insert string from the supplied data
+	 * Generates a platform-specific replace string from the supplied data
 	 *
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	protected function _insert($table, $keys, $values)
+	protected function _replace($table, $keys, $values)
 	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
-	 * Update statement
-	 *
-	 * Generates a platform-specific update string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the update data
-	 * @param	array	the where clause
-	 * @param	array	the orderby clause
-	 * @param	array	the limit clause
-	 * @return	string
-	 */
-	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
-	{
-		foreach ($values as $key => $val)
-		{
-			$valstr[] = $key.' = '.$val;
-		}
-
-		return 'UPDATE '.$table.' SET '.implode(', ', $valstr)
-			.(($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '')
-			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
-			.( ! $limit ? '' : ' LIMIT '.$limit);
+		return 'INSERT OR '.parent::_replace($table, $keys, $values);
 	}
 
 	// --------------------------------------------------------------------
@@ -446,15 +383,16 @@ class CI_DB_sqlite3_driver extends CI_DB {
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command, then
-	 * this method maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command, then,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return $this->_delete($table);
+		return 'DELETE FROM '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlite3/sqlite3_forge.php b/system/database/drivers/sqlite3/sqlite3_forge.php
index 254db21d8..3a2060c3b 100644
--- a/system/database/drivers/sqlite3/sqlite3_forge.php
+++ b/system/database/drivers/sqlite3/sqlite3_forge.php
@@ -95,10 +95,10 @@ class CI_DB_sqlite3_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table).'(';
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
diff --git a/system/database/drivers/sqlsrv/sqlsrv_driver.php b/system/database/drivers/sqlsrv/sqlsrv_driver.php
index bb4f009bc..f4eab8f28 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_driver.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_driver.php
@@ -393,21 +393,6 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Escape the SQL Identifiers
-	 *
-	 * This function escapes column and table names
-	 *
-	 * @param	string
-	 * @return	string
-	 */
-	public function _escape_identifiers($item)
-	{
-		return $item;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
@@ -429,23 +414,6 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	// --------------------------------------------------------------------
 
 	/**
-	 * Insert statement
-	 *
-	 * Generates a platform-specific insert string from the supplied data
-	 *
-	 * @param	string	the table name
-	 * @param	array	the insert keys
-	 * @param	array	the insert values
-	 * @return	string
-	 */
-	protected function _insert($table, $keys, $values)
-	{
-		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
@@ -473,15 +441,16 @@ class CI_DB_sqlsrv_driver extends CI_DB {
 	 * Truncate statement
 	 *
 	 * Generates a platform-specific truncate string from the supplied data
-	 * If the database does not support the truncate() command
-	 * This function maps to "DELETE FROM table"
+	 *
+	 * If the database does not support the truncate() command,
+	 * then this method maps to 'DELETE FROM table'
 	 *
 	 * @param	string	the table name
 	 * @return	string
 	 */
 	protected function _truncate($table)
 	{
-		return "TRUNCATE ".$table;
+		return 'TRUNCATE TABLE '.$table;
 	}
 
 	// --------------------------------------------------------------------
diff --git a/system/database/drivers/sqlsrv/sqlsrv_forge.php b/system/database/drivers/sqlsrv/sqlsrv_forge.php
index 0dc7b5242..377dcf154 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_forge.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_forge.php
@@ -63,11 +63,12 @@ class CI_DB_sqlsrv_forge extends CI_DB_forge {
 	/**
 	 * Drop Table
 	 *
-	 * @return	bool
+	 * @param	string	table name
+	 * @return	string
 	 */
 	public function _drop_table($table)
 	{
-		return "DROP TABLE ".$this->db->_escape_identifiers($table);
+		return 'DROP TABLE '.$this->db->escape_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -91,7 +92,7 @@ class CI_DB_sqlsrv_forge extends CI_DB_forge {
 			$sql .= 'IF NOT EXISTS ';
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
+		$sql .= $this->db->escape_identifiers($table).' (';
 		$current_field_count = 0;
 
 		foreach ($fields as $field => $attributes)