Hi Michal, In fact, in this class we just test for Dummy driver, which the data is faked by us. Look at this line: https://github.com/phpmyadmin/phpmyadmin/blob/master/libraries/database_interface.inc.php#L18

so for dataSeek function, it just check the result: https://github.com/phpmyadmin/phpmyadmin/blob/master/libraries/dbi/DBIDummy.class.php#L439


I am doing the mysql driver and mysqli driver, which must be do it  after executing query. I will at a new test class  database_interface_mysql_test.php