how to check that id is already exists

Question

i am making a window form and entering data from to database if i enter existing id no into my database from the form so a message should be come . please give me some hint

Atul Kumar · Answer

First you read data from database for that particular Id and check if there are any records exists in database or not. If it is already there then you can display a message box. So the thing is to read data before you write it in database. Please mark as accepted if found helpful

Shakti Singh Dulawat · Answer

IF EXISTS ( SELECT * FROM Products WHERE id=? ) BEGIN --dowhatyouneedifexists END ELSE BEGIN --dowhatneedstobedoneifnot END