How to check if a row exists in a PostgreSQL stored procedure?

Question

I writing a stored procedure in postgres where I need to check if a row exists then act accordingly. something along the line.

IF SELECT * FROM foo WHERE x =         


        

Answer 1

Or even simpler with EXISTS:

IF EXISTS (SELECT 1 FROM foo WHERE x = 'abc' AND y = 'xyz') THEN
    ....
END IF;