根据按钮单击复选框从数据库中获取数据

I have table consisting columns(....,....,....,BLOCK) in my database. The BLOCK column has bit datatype(True,False). When BLOCK column has False, the data should be fetched from the database. When BLOCK column has True, the data should not be fetched resulting in throwing an error. When I give the name of a particular person in textbox and click button, the above operation must be performedI have table consisting columns(....,....,....,