Is there a way to set variable in UPDATE statement in PostgreSQL (plpgsql)?

Something like this:

DECLARE
c INTEGER;
UPDATE table SET col = (c := col + 1) WHERE id = 1;

This is wrong:

ERROR:  syntax error at or near ":="

how to do it right?

Assuming the update only affects one row:

DECLARE
c INTEGER;
UPDATE table SET col = col + 1 WHERE id = 1
  RETURNING col INTO c;

Reference.

StackExchange Database Administrators Q#118033, answer score: 4