Case statements will support raise exception or not?

Question

 case when $1 is null then raise exception 'Please enter $1'
      when $2 is null then raise exception 'Please enter $2' 
 end;

Is it will work please can any give me answer

Answer 1

Best I'm aware, it won't. The case operator is for expression branching, as in one-liner statements that returns a value. For more complicated things and raising exceptions, use if … then … end if;.

Answer 2

You can verify on sqlfiddle.com if you like. I did, and it certainly did not work in postgres. Raise is a pl/pgsql command, not an sql command.