Allow a multi-row INSERT to specify DEFAULTs for a generated column.

One can say "INSERT INTO tab(generated_col) VALUES (DEFAULT)" and not
draw an error.  But the equivalent case for a multi-row VALUES list
always threw an error, even if one properly said DEFAULT in each row.
Fix that.  While here, improve the test cases for nearby logic about
OVERRIDING SYSTEM/USER values.

Dean Rasheed

Discussion: https://postgr.es/m/9q0sgcr416t.fsf@gmx.us

src/test/regress/expected/generated.out

@@ -91,17 +91,30 @@ ERROR:  for a generated column, GENERATED ALWAYS must be specified
 LINE 1: ...E gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT...
                                                              ^
 INSERT INTO gtest1 VALUES (1);
-INSERT INTO gtest1 VALUES (2, DEFAULT);
+INSERT INTO gtest1 VALUES (2, DEFAULT);  -- ok
 INSERT INTO gtest1 VALUES (3, 33);  -- error
 ERROR:  cannot insert into column "b"
 DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1 VALUES (3, 33), (4, 44);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, 44);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1 VALUES (3, 33), (4, DEFAULT);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, DEFAULT);  -- ok
 SELECT * FROM gtest1 ORDER BY a;
  a | b 
 ---+---
  1 | 2
  2 | 4
-(2 rows)
+ 3 | 6
+ 4 | 8
+(4 rows)
 
+DELETE FROM gtest1 WHERE a >= 3;
 UPDATE gtest1 SET b = DEFAULT WHERE a = 1;
 UPDATE gtest1 SET b = 11 WHERE a = 1;  -- error
 ERROR:  column "b" can only be updated to DEFAULT
@@ -179,9 +192,37 @@ SELECT * FROM gtest1v;
  3 | 6
 (1 row)
 
-INSERT INTO gtest1v VALUES (4, 8);  -- fails
+INSERT INTO gtest1v VALUES (4, 8);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1v VALUES (5, DEFAULT);  -- ok
+INSERT INTO gtest1v VALUES (6, 66), (7, 77);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, 77);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1v VALUES (6, 66), (7, DEFAULT);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, DEFAULT);  -- ok
+ALTER VIEW gtest1v ALTER COLUMN b SET DEFAULT 100;
+INSERT INTO gtest1v VALUES (8, DEFAULT);  -- error
+ERROR:  cannot insert into column "b"
+DETAIL:  Column "b" is a generated column.
+INSERT INTO gtest1v VALUES (8, DEFAULT), (9, DEFAULT);  -- error
 ERROR:  cannot insert into column "b"
 DETAIL:  Column "b" is a generated column.
+SELECT * FROM gtest1v;
+ a | b  
+---+----
+ 3 |  6
+ 5 | 10
+ 6 | 12
+ 7 | 14
+(4 rows)
+
+DELETE FROM gtest1v WHERE a >= 5;
 DROP VIEW gtest1v;
 -- CTEs
 WITH foo AS (SELECT * FROM gtest1) SELECT * FROM foo;

src/test/regress/expected/identity.out

@@ -105,6 +105,62 @@ SELECT * FROM itest4;
 (2 rows)
 
 -- VALUES RTEs
+CREATE TABLE itest5 (a int generated always as identity, b text);
+INSERT INTO itest5 VALUES (1, 'a');  -- error
+ERROR:  cannot insert into column "a"
+DETAIL:  Column "a" is an identity column defined as GENERATED ALWAYS.
+HINT:  Use OVERRIDING SYSTEM VALUE to override.
+INSERT INTO itest5 VALUES (DEFAULT, 'a');  -- ok
+INSERT INTO itest5 VALUES (2, 'b'), (3, 'c');  -- error
+ERROR:  cannot insert into column "a"
+DETAIL:  Column "a" is an identity column defined as GENERATED ALWAYS.
+HINT:  Use OVERRIDING SYSTEM VALUE to override.
+INSERT INTO itest5 VALUES (DEFAULT, 'b'), (3, 'c');  -- error
+ERROR:  cannot insert into column "a"
+DETAIL:  Column "a" is an identity column defined as GENERATED ALWAYS.
+HINT:  Use OVERRIDING SYSTEM VALUE to override.
+INSERT INTO itest5 VALUES (2, 'b'), (DEFAULT, 'c');  -- error
+ERROR:  cannot insert into column "a"
+DETAIL:  Column "a" is an identity column defined as GENERATED ALWAYS.
+HINT:  Use OVERRIDING SYSTEM VALUE to override.
+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;
+ a  |  b  
+----+-----
+  1 | a
+  2 | b
+  3 | c
+ -1 | aa
+ -2 | bb
+ -3 | cc
+  4 | dd
+ -4 | ee
+ -5 | ff
+  5 | gg
+  6 | hh
+  7 | ii
+  8 | aaa
+  9 | bbb
+ 10 | ccc
+ 11 | ddd
+ 12 | eee
+ 13 | fff
+ 14 | ggg
+ 15 | hhh
+ 16 | iii
+(21 rows)
+
+DROP TABLE itest5;
 INSERT INTO itest3 VALUES (DEFAULT, 'a');
 INSERT INTO itest3 VALUES (DEFAULT, 'b'), (DEFAULT, 'c');
 SELECT * FROM itest3;

src/test/regress/sql/generated.sql

@@ -41,10 +41,15 @@ CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generat
 CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
 
 INSERT INTO gtest1 VALUES (1);
-INSERT INTO gtest1 VALUES (2, DEFAULT);
+INSERT INTO gtest1 VALUES (2, DEFAULT);  -- ok
 INSERT INTO gtest1 VALUES (3, 33);  -- error
+INSERT INTO gtest1 VALUES (3, 33), (4, 44);  -- error
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, 44);  -- error
+INSERT INTO gtest1 VALUES (3, 33), (4, DEFAULT);  -- error
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, DEFAULT);  -- ok
 
 SELECT * FROM gtest1 ORDER BY a;
+DELETE FROM gtest1 WHERE a >= 3;
 
 UPDATE gtest1 SET b = DEFAULT WHERE a = 1;
 UPDATE gtest1 SET b = 11 WHERE a = 1;  -- error
@@ -75,7 +80,19 @@ SELECT * FROM gtest1 ORDER BY a;
 -- views
 CREATE VIEW gtest1v AS SELECT * FROM gtest1;
 SELECT * FROM gtest1v;
-INSERT INTO gtest1v VALUES (4, 8);  -- fails
+INSERT INTO gtest1v VALUES (4, 8);  -- error
+INSERT INTO gtest1v VALUES (5, DEFAULT);  -- ok
+INSERT INTO gtest1v VALUES (6, 66), (7, 77);  -- error
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, 77);  -- error
+INSERT INTO gtest1v VALUES (6, 66), (7, DEFAULT);  -- error
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, DEFAULT);  -- ok
+
+ALTER VIEW gtest1v ALTER COLUMN b SET DEFAULT 100;
+INSERT INTO gtest1v VALUES (8, DEFAULT);  -- error
+INSERT INTO gtest1v VALUES (8, DEFAULT), (9, DEFAULT);  -- error
+
+SELECT * FROM gtest1v;
+DELETE FROM gtest1v WHERE a >= 5;
 DROP VIEW gtest1v;
 
 -- CTEs

src/test/regress/sql/identity.sql

@@ -56,6 +56,29 @@ 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');