Fixed issue #150 (for mysql and mysqli), now returns the actual column length.
diff --git a/system/database/drivers/mysqli/mysqli_driver.php b/system/database/drivers/mysqli/mysqli_driver.php
index ddcaff3..ccd110f 100644
--- a/system/database/drivers/mysqli/mysqli_driver.php
+++ b/system/database/drivers/mysqli/mysqli_driver.php
@@ -442,7 +442,7 @@
 	 */
 	function _field_data($table)
 	{
-		return "SELECT * FROM ".$table." LIMIT 1";
+		return "DESCRIBE ".$table;
 	}
 
 	// --------------------------------------------------------------------