Merge branch 'develop' of git://github.com/EllisLab/CodeIgniter into db-tests

25 files changed, 80 insertions, 512 deletions

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 b2ccec2d4..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);
-	}
-
 	// --------------------------------------------------------------------
 
 	/**
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 fd164cd07..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
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index 055c9decb..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, $str);
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
diff --git a/system/database/drivers/mssql/mssql_forge.php b/system/database/drivers/mssql/mssql_forge.php
index 2e3e314ed..d787b3764 100644
--- a/system/database/drivers/mssql/mssql_forge.php
+++ b/system/database/drivers/mssql/mssql_forge.php
@@ -68,7 +68,7 @@ class CI_DB_mssql_forge extends CI_DB_forge {
 	 */
 	public function _drop_table($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 7afa5acd4..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
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 00bc726c5..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
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 756d93a16..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
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 de5af7bd2..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
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 aec39c819..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
@@ -662,7 +591,7 @@ class CI_DB_pdo_driver extends CI_DB {
 			$tables = array($tables);
 		}
 
-		return (count($tables) == 1) ? '`'.$tables[0].'`' : '('.implode(', ', $tables).')';
+		return (count($tables) === 1) ? $tables[0] : '('.implode(', ', $tables).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -695,7 +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)
@@ -765,7 +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 f95ff560f..1e96452b4 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -457,47 +457,6 @@ 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)
-			{
-				$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
diff --git a/system/database/drivers/postgre/postgre_forge.php b/system/database/drivers/postgre/postgre_forge.php
index a72449820..f7d59284a 100644
--- a/system/database/drivers/postgre/postgre_forge.php
+++ b/system/database/drivers/postgre/postgre_forge.php
@@ -193,8 +193,7 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 			}
 		}
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
-		$sql .= $this->_process_fields($fields, $primary_keys);
+		$sql .= $this->db->escape_identifiers($table).' ('.$this->_process_fields($fields, $primary_keys);
 
 		if (count($primary_keys) > 0)
 		{
@@ -237,11 +236,12 @@ class CI_DB_postgre_forge extends CI_DB_forge {
 	/**
 	 * Drop Table
 	 *
+	 * @param	string	table name
 	 * @return	string
 	 */
 	public function _drop_table($table)
 	{
-		return "DROP TABLE IF EXISTS ".$this->db->_escape_identifiers($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 9c611f2fd..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
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 c78f0c4fe..12354e1bc 100644
--- a/system/database/drivers/sqlite3/sqlite3_driver.php
+++ b/system/database/drivers/sqlite3/sqlite3_driver.php
@@ -342,43 +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
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 f75024799..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 $item;
-	}
-
-	// --------------------------------------------------------------------
-
-	/**
 	 * From Tables
 	 *
 	 * This function implicitly groups FROM tables so there is no confusion
diff --git a/system/database/drivers/sqlsrv/sqlsrv_forge.php b/system/database/drivers/sqlsrv/sqlsrv_forge.php
index 0dc7b5242..377dcf154 100644
--- a/system/database/drivers/sqlsrv/sqlsrv_forge.php
+++ b/system/database/drivers/sqlsrv/sqlsrv_forge.php
@@ -63,11 +63,12 @@ class CI_DB_sqlsrv_forge extends CI_DB_forge {
 	/**
 	 * Drop Table
 	 *
-	 * @return	bool
+	 * @param	string	table name
+	 * @return	string
 	 */
 	public function _drop_table($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)
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index 81644ecac..3ad930ed1 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -75,7 +75,7 @@ Release Date: Not Released
 	 -  Added _optimize_table() support for the :doc:`Database Utility Class <database/utilities>` (rebuilds table indexes).
    -  Added a constructor to the DB_result class and moved all driver-specific properties and logic out of the base DB_driver class to allow better abstraction.
    -  Removed limit() and order_by() support for UPDATE and DELETE queries in PostgreSQL driver. Postgres does not support those features.
-   -  Removed protect_identifiers() and renamed _protect_identifiers() to it instead - it was just an alias.
+   -  Removed protect_identifiers() and renamed internal method _protect_identifiers() to it instead - it was just an alias.
    -  MySQL and MySQLi drivers now require at least MySQL version 5.1.
    -  db_set_charset() now only requires one parameter (collation was only needed due to legacy support for MySQL versions prior to 5.1).
    -  Added DSN string support for CUBRID.
@@ -91,6 +91,7 @@ Release Date: Not Released
 	 -  *Row* result methods now really only fetch only the needed number of rows, instead of depending entirely on result().
 	 -  num_rows() is now only called explicitly by the developer and no longer re-executes statements.
    -  Added replace() support for SQLite.
+   -  Renamed internal method _escape_identifiers() to escape_identifiers().
 
 -  Libraries