psql session

gistfile1.txt

cygnus=# create table parent (a text not null primary key);
CREATE TABLE
cygnus=# create table child (a text not null primary key references parent(a) on delete cascade on update cascade);
CREATE TABLE
cygnus=# insert into parent (a) values ('foobar');
INSERT 0 1
cygnus=# insert into parent (a) values ('foo__bar');
INSERT 0 1
cygnus=# insert into child (a) values ('foo');
ERROR:  insert or update on table "child" violates foreign key constraint "child_a_fkey"
DETAIL:  Key (a)=(foo) is not present in table "parent".
cygnus=# insert into child (a) values ('foobar');
INSERT 0 1
cygnus=# insert into child (a) values ('foo__bar');
INSERT 0 1
cygnus=# begin;
BEGIN
cygnus=# delete from parent;
DELETE 2
cygnus=# select * from child;
 a
---
(0 rows)