Explicitly added driver name variable in each DB driver, based on this bug report: #4436
diff --git a/system/database/drivers/mssql/mssql_driver.php b/system/database/drivers/mssql/mssql_driver.php
index ed6eadb..02b975a 100644
--- a/system/database/drivers/mssql/mssql_driver.php
+++ b/system/database/drivers/mssql/mssql_driver.php
@@ -37,7 +37,8 @@
 	 */

 	var $_count_string = "SELECT COUNT(*) AS ";

 	var $_random_keyword = ' ASC'; // not currently supported

-	

+	var $dbdriver		= 'mssql';

+

 	/**

 	 * Non-persistent database connection

 	 *

diff --git a/system/database/drivers/mysql/mysql_driver.php b/system/database/drivers/mysql/mysql_driver.php
index 52df1e5..db04c6d 100644
--- a/system/database/drivers/mysql/mysql_driver.php
+++ b/system/database/drivers/mysql/mysql_driver.php
@@ -30,6 +30,8 @@
  */

 class CI_DB_mysql_driver extends CI_DB {

 

+	var $dbdriver = 'mysql';

+

 	/**

 	 * Whether to use the MySQL "delete hack" which allows the number

 	 * of affected rows to be shown. Uses a preg_replace when enabled,

diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index 35a7fc0..a5d104c 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -30,6 +30,8 @@
  */

 class CI_DB_mysqli_driver extends CI_DB {

 

+	var $dbdriver = 'mysqli';

+

 	/**

 	 * The syntax to count rows is slightly different across different

 	 * database engines, so this string appears in each driver and is

diff --git a/system/database/drivers/oci8/oci8_driver.php b/system/database/drivers/oci8/oci8_driver.php
index 96a6a13..006e6ef 100644
--- a/system/database/drivers/oci8/oci8_driver.php
+++ b/system/database/drivers/oci8/oci8_driver.php
@@ -43,6 +43,8 @@
 

 class CI_DB_oci8_driver extends CI_DB {

 

+	var $dbdriver = 'oci8';

+

 	/**

 	 * The syntax to count rows is slightly different across different

 	 * database engines, so this string appears in each driver and is

diff --git a/system/database/drivers/odbc/odbc_driver.php b/system/database/drivers/odbc/odbc_driver.php
index 2992880..cc8d334 100644
--- a/system/database/drivers/odbc/odbc_driver.php
+++ b/system/database/drivers/odbc/odbc_driver.php
@@ -30,6 +30,8 @@
  */

 class CI_DB_odbc_driver extends CI_DB {

 

+	var $dbdriver = 'odbc';

+

 	/**

 	 * The syntax to count rows is slightly different across different

 	 * database engines, so this string appears in each driver and is

diff --git a/system/database/drivers/postgre/postgre_driver.php b/system/database/drivers/postgre/postgre_driver.php
index aada164..c5c70a7 100644
--- a/system/database/drivers/postgre/postgre_driver.php
+++ b/system/database/drivers/postgre/postgre_driver.php
@@ -30,6 +30,8 @@
  */

 class CI_DB_postgre_driver extends CI_DB {

 

+	var $dbdriver = 'postgre';

+

 	/**

 	 * The syntax to count rows is slightly different across different

 	 * database engines, so this string appears in each driver and is

diff --git a/system/database/drivers/sqlite/sqlite_driver.php b/system/database/drivers/sqlite/sqlite_driver.php
index 7821569..df19dba 100644
--- a/system/database/drivers/sqlite/sqlite_driver.php
+++ b/system/database/drivers/sqlite/sqlite_driver.php
@@ -32,6 +32,8 @@
  */

 class CI_DB_sqlite_driver extends CI_DB {

 

+	var $dbdriver = 'sqlite';

+

 	/**

 	 * The syntax to count rows is slightly different across different

 	 * database engines, so this string appears in each driver and is