-- sanity check of system catalog
SELECT attrelid, attname, attidentity FROM pg_attribute WHERE attidentity NOT IN ('', 'a', 'd');


CREATE TABLE itest1 (a int generated by default as identity, b text);
CREATE TABLE itest2 (a bigint generated always as identity, b text);
CREATE TABLE itest3 (a smallint generated by default as identity (start with 7 increment by 5), b text);
ALTER TABLE itest3 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;  -- error

SELECT table_name, column_name, column_default, is_nullable, is_identity, identity_generation, identity_start, identity_increment, identity_maximum, identity_minimum, identity_cycle FROM information_schema.columns WHERE table_name LIKE 'itest_' ORDER BY 1, 2;

-- internal sequences should not be shown here
SELECT sequence_name FROM information_schema.sequences WHERE sequence_name LIKE 'itest%';

SELECT pg_get_serial_sequence('itest1', 'a');

\d itest1_a_seq

CREATE TABLE itest4 (a int, b text);
ALTER TABLE itest4 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;  -- error, requires NOT NULL
ALTER TABLE itest4 ALTER COLUMN a SET NOT NULL;
ALTER TABLE itest4 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;  -- ok
ALTER TABLE itest4 ALTER COLUMN a DROP NOT NULL;  -- error, disallowed
ALTER TABLE itest4 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;  -- error, already set
ALTER TABLE itest4 ALTER COLUMN b ADD GENERATED ALWAYS AS IDENTITY;  -- error, wrong data type

-- for later
ALTER TABLE itest4 ALTER COLUMN b SET DEFAULT '';

-- invalid column type
CREATE TABLE itest_err_1 (a text generated by default as identity);

-- duplicate identity
CREATE TABLE itest_err_2 (a int generated always as identity generated by default as identity);

-- cannot have default and identity
CREATE TABLE itest_err_3 (a int default 5 generated by default as identity);

-- cannot combine serial and identity
CREATE TABLE itest_err_4 (a serial generated by default as identity);

INSERT INTO itest1 DEFAULT VALUES;
INSERT INTO itest1 DEFAULT VALUES;
INSERT INTO itest2 DEFAULT VALUES;
INSERT INTO itest2 DEFAULT VALUES;
INSERT INTO itest3 DEFAULT VALUES;
INSERT INTO itest3 DEFAULT VALUES;
INSERT INTO itest4 DEFAULT VALUES;
INSERT INTO itest4 DEFAULT VALUES;

SELECT * FROM itest1;
SELECT * FROM itest2;
SELECT * FROM itest3;
SELECT * FROM itest4;


-- VALUES RTEs

CREATE TABLE itest5 (a int generated always as identity, b text);
INSERT INTO itest5 VALUES (1, 'a');  -- error
INSERT INTO itest5 VALUES (DEFAULT, 'a');  -- ok
INSERT INTO itest5 VALUES (2, 'b'), (3, 'c');  -- error
INSERT INTO itest5 VALUES (DEFAULT, 'b'), (3, 'c');  -- error
INSERT INTO itest5 VALUES (2, 'b'), (DEFAULT, 'c');  -- error
INSERT INTO itest5 VALUES (DEFAULT, 'b'), (DEFAULT, 'c');  -- ok

INSERT INTO itest5 OVERRIDING SYSTEM VALUE VALUES (-1, 'aa');
INSERT INTO itest5 OVERRIDING SYSTEM VALUE VALUES (-2, 'bb'), (-3, 'cc');
INSERT INTO itest5 OVERRIDING SYSTEM VALUE VALUES (DEFAULT, 'dd'), (-4, 'ee');
INSERT INTO itest5 OVERRIDING SYSTEM VALUE VALUES (-5, 'ff'), (DEFAULT, 'gg');
INSERT INTO itest5 OVERRIDING SYSTEM VALUE VALUES (DEFAULT, 'hh'), (DEFAULT, 'ii');

INSERT INTO itest5 OVERRIDING USER VALUE VALUES (-1, 'aaa');
INSERT INTO itest5 OVERRIDING USER VALUE VALUES (-2, 'bbb'), (-3, 'ccc');
INSERT INTO itest5 OVERRIDING USER VALUE VALUES (DEFAULT, 'ddd'), (-4, 'eee');
INSERT INTO itest5 OVERRIDING USER VALUE VALUES (-5, 'fff'), (DEFAULT, 'ggg');
INSERT INTO itest5 OVERRIDING USER VALUE VALUES (DEFAULT, 'hhh'), (DEFAULT, 'iii');

SELECT * FROM itest5;
DROP TABLE itest5;

INSERT INTO itest3 VALUES (DEFAULT, 'a');
INSERT INTO itest3 VALUES (DEFAULT, 'b'), (DEFAULT, 'c');

SELECT * FROM itest3;


-- OVERRIDING tests

-- GENERATED BY DEFAULT

-- This inserts the row as presented:
INSERT INTO itest1 VALUES (10, 'xyz');
-- With GENERATED BY DEFAULT, OVERRIDING SYSTEM VALUE is not allowed
-- by the standard, but we allow it as a no-op, since it is of use if
-- there are multiple identity columns in a table, which is also an
-- extension.
INSERT INTO itest1 OVERRIDING SYSTEM VALUE VALUES (20, 'xyz');
-- This ignores the 30 and uses the sequence value instead:
INSERT INTO itest1 OVERRIDING USER VALUE VALUES (30, 'xyz');

SELECT * FROM itest1;

-- GENERATED ALWAYS

-- This is an error:
INSERT INTO itest2 VALUES (10, 'xyz');
-- This inserts the row as presented:
INSERT INTO itest2 OVERRIDING SYSTEM VALUE VALUES (20, 'xyz');
-- This ignores the 30 and uses the sequence value instead:
INSERT INTO itest2 OVERRIDING USER VALUE VALUES (30, 'xyz');

SELECT * FROM itest2;


-- UPDATE tests

-- GENERATED BY DEFAULT is not restricted.
UPDATE itest1 SET a = 101 WHERE a = 1;
UPDATE itest1 SET a = DEFAULT WHERE a = 2;
SELECT * FROM itest1;

-- GENERATED ALWAYS allows only DEFAULT.
UPDATE itest2 SET a = 101 WHERE a = 1;  -- error
UPDATE itest2 SET a = DEFAULT WHERE a = 2;  -- ok
SELECT * FROM itest2;


-- COPY tests

CREATE TABLE itest9 (a int GENERATED ALWAYS AS IDENTITY, b text, c bigint);

COPY itest9 FROM stdin;
100	foo	200
101	bar	201
\.

COPY itest9 (b, c) FROM stdin;
foo2	202
bar2	203
\.

SELECT * FROM itest9 ORDER BY c;


-- DROP IDENTITY tests

ALTER TABLE itest4 ALTER COLUMN a DROP IDENTITY;
ALTER TABLE itest4 ALTER COLUMN a DROP IDENTITY;  -- error
ALTER TABLE itest4 ALTER COLUMN a DROP IDENTITY IF EXISTS;  -- noop

INSERT INTO itest4 DEFAULT VALUES;  -- fails because NOT NULL is not dropped
ALTER TABLE itest4 ALTER COLUMN a DROP NOT NULL;
INSERT INTO itest4 DEFAULT VALUES;
SELECT * FROM itest4;

-- check that sequence is removed
SELECT sequence_name FROM itest4_a_seq;


-- test views

CREATE TABLE itest10 (a int generated by default as identity, b text);
CREATE TABLE itest11 (a int generated always as identity, b text);

CREATE VIEW itestv10 AS SELECT * FROM itest10;
CREATE VIEW itestv11 AS SELECT * FROM itest11;

INSERT INTO itestv10 DEFAULT VALUES;
INSERT INTO itestv10 DEFAULT VALUES;

INSERT INTO itestv11 DEFAULT VALUES;
INSERT INTO itestv11 DEFAULT VALUES;

SELECT * FROM itestv10;
SELECT * FROM itestv11;

INSERT INTO itestv10 VALUES (10, 'xyz');
INSERT INTO itestv10 OVERRIDING USER VALUE VALUES (11, 'xyz');

SELECT * FROM itestv10;

INSERT INTO itestv11 VALUES (10, 'xyz');
INSERT INTO itestv11 OVERRIDING SYSTEM VALUE VALUES (11, 'xyz');

SELECT * FROM itestv11;

DROP VIEW itestv10, itestv11;


-- ADD COLUMN

CREATE TABLE itest13 (a int);
-- add column to empty table
ALTER TABLE itest13 ADD COLUMN b int GENERATED BY DEFAULT AS IDENTITY;
INSERT INTO itest13 VALUES (1), (2), (3);
-- add column to populated table
ALTER TABLE itest13 ADD COLUMN c int GENERATED BY DEFAULT AS IDENTITY;
SELECT * FROM itest13;


-- various ALTER COLUMN tests

-- fail, not allowed for identity columns
ALTER TABLE itest1 ALTER COLUMN a SET DEFAULT 1;

-- fail, not allowed, already has a default
CREATE TABLE itest5 (a serial, b text);
ALTER TABLE itest5 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;

ALTER TABLE itest3 ALTER COLUMN a TYPE int;
SELECT seqtypid::regtype FROM pg_sequence WHERE seqrelid = 'itest3_a_seq'::regclass;
\d itest3

ALTER TABLE itest3 ALTER COLUMN a TYPE text;  -- error

-- check that unlogged propagates to sequence
CREATE UNLOGGED TABLE itest17 (a int NOT NULL, b text);
ALTER TABLE itest17 ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;
ALTER TABLE itest17 ADD COLUMN c int GENERATED ALWAYS AS IDENTITY;
\d itest17
\d itest17_a_seq
\d itest17_c_seq
CREATE TABLE itest18 (a int NOT NULL, b text);
ALTER TABLE itest18 SET UNLOGGED, ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;
\d itest18
\d itest18_a_seq
ALTER TABLE itest18 SET LOGGED;
\d itest18
\d itest18_a_seq
ALTER TABLE itest18 SET UNLOGGED;
\d itest18
\d itest18_a_seq

-- kinda silly to change property in the same command, but it should work
ALTER TABLE itest3
  ADD COLUMN c int GENERATED BY DEFAULT AS IDENTITY,
  ALTER COLUMN c SET GENERATED ALWAYS;
\d itest3


-- ALTER COLUMN ... SET

CREATE TABLE itest6 (a int GENERATED ALWAYS AS IDENTITY, b text);
INSERT INTO itest6 DEFAULT VALUES;

ALTER TABLE itest6 ALTER COLUMN a SET GENERATED BY DEFAULT SET INCREMENT BY 2 SET START WITH 100 RESTART;
INSERT INTO itest6 DEFAULT VALUES;
INSERT INTO itest6 DEFAULT VALUES;
SELECT * FROM itest6;

SELECT table_name, column_name, is_identity, identity_generation FROM information_schema.columns WHERE table_name = 'itest6' ORDER BY 1, 2;

ALTER TABLE itest6 ALTER COLUMN b SET INCREMENT BY 2;  -- fail, not identity


-- prohibited direct modification of sequence

ALTER SEQUENCE itest6_a_seq OWNED BY NONE;


-- inheritance

CREATE TABLE itest7 (a int GENERATED ALWAYS AS IDENTITY);
INSERT INTO itest7 DEFAULT VALUES;
SELECT * FROM itest7;

-- identity property is not inherited
CREATE TABLE itest7a (b text) INHERITS (itest7);

-- make column identity in child table
CREATE TABLE itest7b (a int);
CREATE TABLE itest7c (a int GENERATED ALWAYS AS IDENTITY) INHERITS (itest7b);
INSERT INTO itest7c DEFAULT VALUES;
SELECT * FROM itest7c;

CREATE TABLE itest7d (a int not null);
CREATE TABLE itest7e () INHERITS (itest7d);
ALTER TABLE itest7d ALTER COLUMN a ADD GENERATED ALWAYS AS IDENTITY;
ALTER TABLE itest7d ADD COLUMN b int GENERATED ALWAYS AS IDENTITY;  -- error

SELECT table_name, column_name, is_nullable, is_identity, identity_generation FROM information_schema.columns WHERE table_name LIKE 'itest7%' ORDER BY 1, 2;

-- These ALTER TABLE variants will not recurse.
ALTER TABLE itest7 ALTER COLUMN a SET GENERATED BY DEFAULT;
ALTER TABLE itest7 ALTER COLUMN a RESTART;
ALTER TABLE itest7 ALTER COLUMN a DROP IDENTITY;

-- privileges
CREATE USER regress_identity_user1;
CREATE TABLE itest8 (a int GENERATED ALWAYS AS IDENTITY, b text);
GRANT SELECT, INSERT ON itest8 TO regress_identity_user1;
SET ROLE regress_identity_user1;
INSERT INTO itest8 DEFAULT VALUES;
SELECT * FROM itest8;
RESET ROLE;
DROP TABLE itest8;
DROP USER regress_identity_user1;

-- multiple steps in ALTER TABLE
CREATE TABLE itest8 (f1 int);

ALTER TABLE itest8
  ADD COLUMN f2 int NOT NULL,
  ALTER COLUMN f2 ADD GENERATED ALWAYS AS IDENTITY;

ALTER TABLE itest8
  ADD COLUMN f3 int NOT NULL,
  ALTER COLUMN f3 ADD GENERATED ALWAYS AS IDENTITY,
  ALTER COLUMN f3 SET GENERATED BY DEFAULT SET INCREMENT 10;

ALTER TABLE itest8
  ADD COLUMN f4 int;

ALTER TABLE itest8
  ALTER COLUMN f4 SET NOT NULL,
  ALTER COLUMN f4 ADD GENERATED ALWAYS AS IDENTITY,
  ALTER COLUMN f4 SET DATA TYPE bigint;

ALTER TABLE itest8
  ADD COLUMN f5 int GENERATED ALWAYS AS IDENTITY;

ALTER TABLE itest8
  ALTER COLUMN f5 DROP IDENTITY,
  ALTER COLUMN f5 DROP NOT NULL,
  ALTER COLUMN f5 SET DATA TYPE bigint;

INSERT INTO itest8 VALUES(0), (1);

-- This does not work when the table isn't empty.  That's intentional,
-- since ADD GENERATED should only affect later insertions:
ALTER TABLE itest8
  ADD COLUMN f22 int NOT NULL,
  ALTER COLUMN f22 ADD GENERATED ALWAYS AS IDENTITY;

TABLE itest8;
\d+ itest8
\d itest8_f2_seq
\d itest8_f3_seq
\d itest8_f4_seq
\d itest8_f5_seq
DROP TABLE itest8;


-- typed tables (currently not supported)

CREATE TYPE itest_type AS (f1 integer, f2 text, f3 bigint);
CREATE TABLE itest12 OF itest_type (f1 WITH OPTIONS GENERATED ALWAYS AS IDENTITY); -- error
DROP TYPE itest_type CASCADE;


-- table partitions (currently not supported)

CREATE TABLE itest_parent (f1 date NOT NULL, f2 text, f3 bigint) PARTITION BY RANGE (f1);
CREATE TABLE itest_child PARTITION OF itest_parent (
    f3 WITH OPTIONS GENERATED ALWAYS AS IDENTITY
) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
DROP TABLE itest_parent;


-- test that sequence of half-dropped serial column is properly ignored

CREATE TABLE itest14 (id serial);
ALTER TABLE itest14 ALTER id DROP DEFAULT;
ALTER TABLE itest14 ALTER id ADD GENERATED BY DEFAULT AS IDENTITY;
INSERT INTO itest14 (id) VALUES (DEFAULT);

-- Identity columns must be NOT NULL (cf bug #16913)

CREATE TABLE itest15 (id integer GENERATED ALWAYS AS IDENTITY NULL); -- fail
CREATE TABLE itest15 (id integer NULL GENERATED ALWAYS AS IDENTITY); -- fail
CREATE TABLE itest15 (id integer GENERATED ALWAYS AS IDENTITY NOT NULL);
DROP TABLE itest15;
CREATE TABLE itest15 (id integer NOT NULL GENERATED ALWAYS AS IDENTITY);
DROP TABLE itest15;

-- MERGE tests
CREATE TABLE itest15 (a int GENERATED ALWAYS AS IDENTITY, b text);
CREATE TABLE itest16 (a int GENERATED BY DEFAULT AS IDENTITY, b text);

MERGE INTO itest15 t
USING (SELECT 10 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) VALUES (s.s_a, s.s_b);

-- Used to fail, but now it works and ignores the user supplied value
MERGE INTO itest15 t
USING (SELECT 20 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) OVERRIDING USER VALUE VALUES (s.s_a, s.s_b);

MERGE INTO itest15 t
USING (SELECT 30 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) OVERRIDING SYSTEM VALUE VALUES (s.s_a, s.s_b);

MERGE INTO itest16 t
USING (SELECT 10 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) VALUES (s.s_a, s.s_b);

MERGE INTO itest16 t
USING (SELECT 20 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) OVERRIDING USER VALUE VALUES (s.s_a, s.s_b);

MERGE INTO itest16 t
USING (SELECT 30 AS s_a, 'inserted by merge' AS s_b) s
ON t.a = s.s_a
WHEN NOT MATCHED THEN
	INSERT (a, b) OVERRIDING SYSTEM VALUE VALUES (s.s_a, s.s_b);

SELECT * FROM itest15;
SELECT * FROM itest16;
DROP TABLE itest15;
DROP TABLE itest16;