foreign_key.sql

来自「postgresql8.3.4源码,开源数据库」· SQL 代码 · 共 924 行 · 第 1/2 页

-- not an implicit coercion (or use numeric=numeric, but that's not part
-- of the integer opfamily)
CREATE TABLE FKTABLE (ftest1 numeric REFERENCES pktable);
DROP TABLE PKTABLE;
-- On the other hand, this should work because int implicitly promotes to
-- numeric, and we allow promotion on the FK side
CREATE TABLE PKTABLE (ptest1 numeric PRIMARY KEY);
INSERT INTO PKTABLE VALUES(42);
CREATE TABLE FKTABLE (ftest1 int REFERENCES pktable);
-- Check it actually works
INSERT INTO FKTABLE VALUES(42);		-- should succeed
INSERT INTO FKTABLE VALUES(43);		-- should fail
UPDATE FKTABLE SET ftest1 = ftest1;	-- should succeed
UPDATE FKTABLE SET ftest1 = ftest1 + 1;	-- should fail
DROP TABLE FKTABLE;
DROP TABLE PKTABLE;

-- Two columns, two tables
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, PRIMARY KEY(ptest1, ptest2));
-- This should fail, because we just chose really odd types
CREATE TABLE FKTABLE (ftest1 cidr, ftest2 timestamp, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable);
-- Again, so should this...
CREATE TABLE FKTABLE (ftest1 cidr, ftest2 timestamp, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest1, ptest2));
-- This fails because we mixed up the column ordering
CREATE TABLE FKTABLE (ftest1 int, ftest2 inet, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable);
-- As does this...
CREATE TABLE FKTABLE (ftest1 int, ftest2 inet, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable(ptest1, ptest2));
-- And again..
CREATE TABLE FKTABLE (ftest1 int, ftest2 inet, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest2, ptest1));
-- This works...
CREATE TABLE FKTABLE (ftest1 int, ftest2 inet, FOREIGN KEY(ftest2, ftest1) REFERENCES pktable(ptest2, ptest1));
DROP TABLE FKTABLE;
-- As does this
CREATE TABLE FKTABLE (ftest1 int, ftest2 inet, FOREIGN KEY(ftest1, ftest2) REFERENCES pktable(ptest1, ptest2));
DROP TABLE FKTABLE;
DROP TABLE PKTABLE;

-- Two columns, same table
-- Make sure this still works...
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, ptest3 int, ptest4 inet, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
ptest4) REFERENCES pktable(ptest1, ptest2));
DROP TABLE PKTABLE;
-- And this, 
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, ptest3 int, ptest4 inet, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
ptest4) REFERENCES pktable);
DROP TABLE PKTABLE;
-- This shouldn't (mixed up columns)
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, ptest3 int, ptest4 inet, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest3,
ptest4) REFERENCES pktable(ptest2, ptest1));
-- Nor should this... (same reason, we have 4,3 referencing 1,2 which mismatches types
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, ptest3 int, ptest4 inet, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest4,
ptest3) REFERENCES pktable(ptest1, ptest2));
-- Not this one either... Same as the last one except we didn't defined the columns being referenced.
CREATE TABLE PKTABLE (ptest1 int, ptest2 inet, ptest3 int, ptest4 inet, PRIMARY KEY(ptest1, ptest2), FOREIGN KEY(ptest4,
ptest3) REFERENCES pktable);

--
-- Now some cases with inheritance
-- Basic 2 table case: 1 column of matching types.
create table pktable_base (base1 int not null);
create table pktable (ptest1 int, primary key(base1), unique(base1, ptest1)) inherits (pktable_base);
create table fktable (ftest1 int references pktable(base1));
-- now some ins, upd, del
insert into pktable(base1) values (1);
insert into pktable(base1) values (2);
--  let's insert a non-existant fktable value
insert into fktable(ftest1) values (3);
--  let's make a valid row for that
insert into pktable(base1) values (3);
insert into fktable(ftest1) values (3);
-- let's try removing a row that should fail from pktable
delete from pktable where base1>2;
-- okay, let's try updating all of the base1 values to *4
-- which should fail.
update pktable set base1=base1*4;
-- okay, let's try an update that should work.
update pktable set base1=base1*4 where base1<3;
-- and a delete that should work
delete from pktable where base1>3;
-- cleanup
drop table fktable;
delete from pktable;

-- Now 2 columns 2 tables, matching types
create table fktable (ftest1 int, ftest2 int, foreign key(ftest1, ftest2) references pktable(base1, ptest1));
-- now some ins, upd, del
insert into pktable(base1, ptest1) values (1, 1);
insert into pktable(base1, ptest1) values (2, 2);
--  let's insert a non-existant fktable value
insert into fktable(ftest1, ftest2) values (3, 1);
--  let's make a valid row for that
insert into pktable(base1,ptest1) values (3, 1);
insert into fktable(ftest1, ftest2) values (3, 1);
-- let's try removing a row that should fail from pktable
delete from pktable where base1>2;
-- okay, let's try updating all of the base1 values to *4
-- which should fail.
update pktable set base1=base1*4;
-- okay, let's try an update that should work.
update pktable set base1=base1*4 where base1<3;
-- and a delete that should work
delete from pktable where base1>3;
-- cleanup
drop table fktable;
drop table pktable;
drop table pktable_base;

-- Now we'll do one all in 1 table with 2 columns of matching types
create table pktable_base(base1 int not null, base2 int);
create table pktable(ptest1 int, ptest2 int, primary key(base1, ptest1), foreign key(base2, ptest2) references
                                             pktable(base1, ptest1)) inherits (pktable_base);
insert into pktable (base1, ptest1, base2, ptest2) values (1, 1, 1, 1);
insert into pktable (base1, ptest1, base2, ptest2) values (2, 1, 1, 1);
insert into pktable (base1, ptest1, base2, ptest2) values (2, 2, 2, 1);
insert into pktable (base1, ptest1, base2, ptest2) values (1, 3, 2, 2);
-- fails (3,2) isn't in base1, ptest1
insert into pktable (base1, ptest1, base2, ptest2) values (2, 3, 3, 2);
-- fails (2,2) is being referenced
delete from pktable where base1=2;
-- fails (1,1) is being referenced (twice)
update pktable set base1=3 where base1=1;
-- this sequence of two deletes will work, since after the first there will be no (2,*) references
delete from pktable where base2=2;
delete from pktable where base1=2;
drop table pktable;
drop table pktable_base;

-- 2 columns (2 tables), mismatched types
create table pktable_base(base1 int not null);
create table pktable(ptest1 inet, primary key(base1, ptest1)) inherits (pktable_base);
-- just generally bad types (with and without column references on the referenced table)
create table fktable(ftest1 cidr, ftest2 int[], foreign key (ftest1, ftest2) references pktable);
create table fktable(ftest1 cidr, ftest2 int[], foreign key (ftest1, ftest2) references pktable(base1, ptest1));
-- let's mix up which columns reference which
create table fktable(ftest1 int, ftest2 inet, foreign key(ftest2, ftest1) references pktable);
create table fktable(ftest1 int, ftest2 inet, foreign key(ftest2, ftest1) references pktable(base1, ptest1));
create table fktable(ftest1 int, ftest2 inet, foreign key(ftest1, ftest2) references pktable(ptest1, base1));
drop table pktable;
drop table pktable_base;

-- 2 columns (1 table), mismatched types
create table pktable_base(base1 int not null, base2 int);
create table pktable(ptest1 inet, ptest2 inet[], primary key(base1, ptest1), foreign key(base2, ptest2) references
                                             pktable(base1, ptest1)) inherits (pktable_base);
create table pktable(ptest1 inet, ptest2 inet, primary key(base1, ptest1), foreign key(base2, ptest2) references
                                             pktable(ptest1, base1)) inherits (pktable_base);
create table pktable(ptest1 inet, ptest2 inet, primary key(base1, ptest1), foreign key(ptest2, base2) references
                                             pktable(base1, ptest1)) inherits (pktable_base);
create table pktable(ptest1 inet, ptest2 inet, primary key(base1, ptest1), foreign key(ptest2, base2) references
                                             pktable(base1, ptest1)) inherits (pktable_base);
drop table pktable;
drop table pktable_base;

--
-- Deferrable constraints
--		(right now, only FOREIGN KEY constraints can be deferred)
--

-- deferrable, explicitly deferred
CREATE TABLE pktable (
	id		INT4 PRIMARY KEY,
	other	INT4
);

CREATE TABLE fktable (
	id		INT4 PRIMARY KEY,
	fk		INT4 REFERENCES pktable DEFERRABLE
);

-- default to immediate: should fail
INSERT INTO fktable VALUES (5, 10);

-- explicitly defer the constraint
BEGIN;

SET CONSTRAINTS ALL DEFERRED;

INSERT INTO fktable VALUES (10, 15);
INSERT INTO pktable VALUES (15, 0); -- make the FK insert valid

COMMIT;

DROP TABLE fktable, pktable;

-- deferrable, initially deferred
CREATE TABLE pktable (
	id		INT4 PRIMARY KEY,
	other	INT4
);

CREATE TABLE fktable (
	id		INT4 PRIMARY KEY,
	fk		INT4 REFERENCES pktable DEFERRABLE INITIALLY DEFERRED
);

-- default to deferred, should succeed
BEGIN;

INSERT INTO fktable VALUES (100, 200);
INSERT INTO pktable VALUES (200, 500); -- make the FK insert valid

COMMIT;

-- default to deferred, explicitly make immediate
BEGIN;

SET CONSTRAINTS ALL IMMEDIATE;

-- should fail
INSERT INTO fktable VALUES (500, 1000);

COMMIT;

DROP TABLE fktable, pktable;

-- tricky behavior: according to SQL99, if a deferred constraint is set
-- to 'immediate' mode, it should be checked for validity *immediately*,
-- not when the current transaction commits (i.e. the mode change applies
-- retroactively)
CREATE TABLE pktable (
	id		INT4 PRIMARY KEY,
	other	INT4
);

CREATE TABLE fktable (
	id		INT4 PRIMARY KEY,
	fk		INT4 REFERENCES pktable DEFERRABLE
);

BEGIN;

SET CONSTRAINTS ALL DEFERRED;

-- should succeed, for now
INSERT INTO fktable VALUES (1000, 2000);

-- should cause transaction abort, due to preceding error
SET CONSTRAINTS ALL IMMEDIATE;

INSERT INTO pktable VALUES (2000, 3); -- too late

COMMIT;

DROP TABLE fktable, pktable;

-- deferrable, initially deferred
CREATE TABLE pktable (
	id		INT4 PRIMARY KEY,
	other	INT4
);

CREATE TABLE fktable (
	id		INT4 PRIMARY KEY,
	fk		INT4 REFERENCES pktable DEFERRABLE INITIALLY DEFERRED
);

BEGIN;

-- no error here
INSERT INTO fktable VALUES (100, 200);

-- error here on commit
COMMIT;

DROP TABLE pktable, fktable CASCADE;

-- test notice about expensive referential integrity checks,
-- where the index cannot be used because of type incompatibilities.

CREATE TEMP TABLE pktable (
        id1     INT4 PRIMARY KEY,
        id2     VARCHAR(4) UNIQUE,
        id3     REAL UNIQUE,
        UNIQUE(id1, id2, id3)
);

CREATE TEMP TABLE fktable (
        x1      INT4 REFERENCES pktable(id1),
        x2      VARCHAR(4) REFERENCES pktable(id2),
        x3      REAL REFERENCES pktable(id3),
        x4      TEXT,
        x5      INT2
);

-- check individual constraints with alter table.

-- should fail

-- varchar does not promote to real
ALTER TABLE fktable ADD CONSTRAINT fk_2_3
FOREIGN KEY (x2) REFERENCES pktable(id3);

-- nor to int4
ALTER TABLE fktable ADD CONSTRAINT fk_2_1
FOREIGN KEY (x2) REFERENCES pktable(id1);

-- real does not promote to int4
ALTER TABLE fktable ADD CONSTRAINT fk_3_1
FOREIGN KEY (x3) REFERENCES pktable(id1);

-- int4 does not promote to text
ALTER TABLE fktable ADD CONSTRAINT fk_1_2
FOREIGN KEY (x1) REFERENCES pktable(id2);

-- should succeed

-- int4 promotes to real
ALTER TABLE fktable ADD CONSTRAINT fk_1_3
FOREIGN KEY (x1) REFERENCES pktable(id3);

-- text is compatible with varchar
ALTER TABLE fktable ADD CONSTRAINT fk_4_2
FOREIGN KEY (x4) REFERENCES pktable(id2);

-- int2 is part of integer opfamily as of 8.0
ALTER TABLE fktable ADD CONSTRAINT fk_5_1
FOREIGN KEY (x5) REFERENCES pktable(id1);

-- check multikey cases, especially out-of-order column lists

-- these should work

ALTER TABLE fktable ADD CONSTRAINT fk_123_123
FOREIGN KEY (x1,x2,x3) REFERENCES pktable(id1,id2,id3);

ALTER TABLE fktable ADD CONSTRAINT fk_213_213
FOREIGN KEY (x2,x1,x3) REFERENCES pktable(id2,id1,id3);

ALTER TABLE fktable ADD CONSTRAINT fk_253_213
FOREIGN KEY (x2,x5,x3) REFERENCES pktable(id2,id1,id3);

-- these should fail

ALTER TABLE fktable ADD CONSTRAINT fk_123_231
FOREIGN KEY (x1,x2,x3) REFERENCES pktable(id2,id3,id1);

ALTER TABLE fktable ADD CONSTRAINT fk_241_132
FOREIGN KEY (x2,x4,x1) REFERENCES pktable(id1,id3,id2);

DROP TABLE pktable, fktable CASCADE;

-- test a tricky case: we can elide firing the FK check trigger during
-- an UPDATE if the UPDATE did not change the foreign key
-- field. However, we can't do this if our transaction was the one that
-- created the updated row and the trigger is deferred, since our UPDATE
-- will have invalidated the original newly-inserted tuple, and therefore
-- cause the on-INSERT RI trigger not to be fired.

CREATE TEMP TABLE pktable (
    id int primary key,
    other int
);

CREATE TEMP TABLE fktable (
    id int primary key,
    fk int references pktable deferrable initially deferred
);

INSERT INTO pktable VALUES (5, 10);

BEGIN;

-- doesn't match PK, but no error yet
INSERT INTO fktable VALUES (0, 20);

-- don't change FK
UPDATE fktable SET id = id + 1;

-- should catch error from initial INSERT
COMMIT;

-- check same case when insert is in a different subtransaction than update

BEGIN;

-- doesn't match PK, but no error yet
INSERT INTO fktable VALUES (0, 20);

-- UPDATE will be in a subxact
SAVEPOINT savept1;

-- don't change FK
UPDATE fktable SET id = id + 1;

-- should catch error from initial INSERT
COMMIT;

BEGIN;

-- INSERT will be in a subxact
SAVEPOINT savept1;

-- doesn't match PK, but no error yet
INSERT INTO fktable VALUES (0, 20);

RELEASE SAVEPOINT savept1;

-- don't change FK
UPDATE fktable SET id = id + 1;

-- should catch error from initial INSERT
COMMIT;

BEGIN;

-- doesn't match PK, but no error yet
INSERT INTO fktable VALUES (0, 20);

-- UPDATE will be in a subxact
SAVEPOINT savept1;

-- don't change FK
UPDATE fktable SET id = id + 1;

-- Roll back the UPDATE
ROLLBACK TO savept1;

-- should catch error from initial INSERT
COMMIT;

-- test order of firing of FK triggers when several RI-induced changes need to
-- be made to the same row.  This was broken by subtransaction-related
-- changes in 8.0.

CREATE TEMP TABLE users (
  id INT PRIMARY KEY,
  name VARCHAR NOT NULL
);

INSERT INTO users VALUES (1, 'Jozko');
INSERT INTO users VALUES (2, 'Ferko');
INSERT INTO users VALUES (3, 'Samko');

CREATE TEMP TABLE tasks (
  id INT PRIMARY KEY,
  owner INT REFERENCES users ON UPDATE CASCADE ON DELETE SET NULL,
  worker INT REFERENCES users ON UPDATE CASCADE ON DELETE SET NULL,
  checked_by INT REFERENCES users ON UPDATE CASCADE ON DELETE SET NULL
);

INSERT INTO tasks VALUES (1,1,NULL,NULL);
INSERT INTO tasks VALUES (2,2,2,NULL);
INSERT INTO tasks VALUES (3,3,3,3);

SELECT * FROM tasks;

UPDATE users SET id = 4 WHERE id = 3;

SELECT * FROM tasks;

DELETE FROM users WHERE id = 4;

SELECT * FROM tasks;

-- could fail with only 2 changes to make, if row was already updated
BEGIN;
UPDATE tasks set id=id WHERE id=2;
SELECT * FROM tasks;
DELETE FROM users WHERE id = 2;
SELECT * FROM tasks;
COMMIT;