Add BETWEEN to _has_operator()
diff --git a/system/database/DB_driver.php b/system/database/DB_driver.php
index d6f9f9c..48f9fb5 100644
--- a/system/database/DB_driver.php
+++ b/system/database/DB_driver.php
@@ -1062,7 +1062,7 @@
 	 */
 	protected function _has_operator($str)
 	{
-		return (bool) preg_match('/(\s|<|>|!|=|IS NULL|IS NOT NULL)/i', trim($str));
+		return (bool) preg_match('/(\s|<|>|!|=|IS NULL|IS NOT NULL|BETWEEN)/i', trim($str));
 	}
 
 	// --------------------------------------------------------------------