SET CONSTRAINTS ALL DEFERRED not working as expected

Question

In a PostgreSQL 9.3 database, if I define tables a and b as follows:

CREATE TABLE a(i integer);
ALTER TABLE a ADD CONSTRAINT pkey_a         


        

Answer 1

I agree with others that the right way to do it is in the right order - but there are just times when that is not a feasible option and something easier is needed to get the job done within the time budget.

In case this helps anyone, I made a procedure that will automate adding the deferred option to all FKs so that the

SET CONSTRAINTS ALL DEFERRED;

command will work. Use it only as necessary of course.

DO
$$
DECLARE
    temp_rec RECORD;
    sql_exe TEXT;
BEGIN

sql_exe := $sql$
ALTER TABLE %1$s ALTER CONSTRAINT %2$s DEFERRABLE;
$sql$
;

FOR temp_rec IN 

(select constraint_name, table_name from information_schema.table_constraints where constraint_type = 'FOREIGN KEY')

LOOP
    EXECUTE format(sql_exe, temp_rec.table_name, temp_rec.constraint_name);
END LOOP;

END;
$$
LANGUAGE plpgsql
;