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Fix LATERAL references to target table of UPDATE/DELETE.

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I failed to think much about UPDATE/DELETE when implementing LATERAL :-(.
The implemented behavior ended up being that subqueries in the FROM or
USING clause (respectively) could access the update/delete target table as
though it were a lateral reference; which seems fine if they said LATERAL,
but certainly ought to draw an error if they didn't.  Fix it so you get a
suitable error when you omit LATERAL.  Per report from Emre Hasegeli.
This commit is contained in:
Tom Lane
2014-01-07 15:25:19 -05:00
parent 91c2755fcb
commit 0a43e5466c
5 changed files with 95 additions and 0 deletions
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48
src/test/regress/expected/join.out
View File

@@ -4055,3 +4055,51 @@ select 1 from tenk1 a, lateral (select max(a.unique1) from int4_tbl b) ss;
ERROR: aggregate functions are not allowed in FROM clause of their own query level
LINE 1: select 1 from tenk1 a, lateral (select max(a.unique1) from i...
^
-- check behavior of LATERAL in UPDATE/DELETE
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
select * from xx1;
x1 | x2
-------------+-------------
0 | 0
123456 | -123456
-123456 | 123456
2147483647 | -2147483647
-2147483647 | 2147483647
(5 rows)
-- error, can't do this without LATERAL:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
ERROR: column "x1" does not exist
LINE 1: ... set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
^
HINT: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = xx1.x1) ss;
ERROR: invalid reference to FROM-clause entry for table "xx1"
LINE 1: ...t x2 = f1 from (select * from int4_tbl where f1 = xx1.x1) ss...
^
HINT: There is an entry for table "xx1", but it cannot be referenced from this part of the query.
-- OK:
update xx1 set x2 = f1 from lateral (select * from int4_tbl where f1 = x1) ss;
select * from xx1;
x1 | x2
-------------+-------------
0 | 0
123456 | 123456
-123456 | -123456
2147483647 | 2147483647
-2147483647 | -2147483647
(5 rows)
-- error:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
ERROR: column "x1" does not exist
LINE 1: ...te from xx1 using (select * from int4_tbl where f1 = x1) ss;
^
HINT: There is a column named "x1" in table "xx1", but it cannot be referenced from this part of the query.
-- OK:
delete from xx1 using lateral (select * from int4_tbl where f1 = x1) ss;
select * from xx1;
x1 | x2
----+----
(0 rows)

18
src/test/regress/sql/join.sql
View File

@@ -1133,3 +1133,21 @@ select * from
int8_tbl x cross join (int4_tbl x cross join lateral (select x.f1) ss);
-- LATERAL can be used to put an aggregate into the FROM clause of its query
select 1 from tenk1 a, lateral (select max(a.unique1) from int4_tbl b) ss;
-- check behavior of LATERAL in UPDATE/DELETE
create temp table xx1 as select f1 as x1, -f1 as x2 from int4_tbl;
select * from xx1;
-- error, can't do this without LATERAL:
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = x1) ss;
update xx1 set x2 = f1 from (select * from int4_tbl where f1 = xx1.x1) ss;
-- OK:
update xx1 set x2 = f1 from lateral (select * from int4_tbl where f1 = x1) ss;
select * from xx1;
-- error:
delete from xx1 using (select * from int4_tbl where f1 = x1) ss;
-- OK:
delete from xx1 using lateral (select * from int4_tbl where f1 = x1) ss;
select * from xx1;