Store query result in a variable using in PL/pgSQL

Question

How to assign the result of a query to a variable in PL/pgSQL, the procedural language of PostgreSQL?

I have a function:

CREATE OR REPLACE FUNCTION t         


        

Answer 1

The usual pattern is EXISTS(subselect):

BEGIN
  IF EXISTS(SELECT name
              FROM test_table t
             WHERE t.id = x
               AND t.name = 'test')
  THEN
     ---
  ELSE
     ---
  END IF;

This pattern is used in PL/SQL, PL/pgSQL, SQL/PSM, ...