On Fri, Dec 21, 2012 at 9:46 PM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> I'm having a hard time following this. Can you provide a concrete example? > > regression=# create table t1 (x int, y int); > CREATE TABLE > regression=# create table t2 (x int, z int); > CREATE TABLE > regression=# create view v1 as select * from t1 join t2 using (x); > CREATE VIEW > regression=# \d+ v1 > View "public.v1" > Column | Type | Modifiers | Storage | Description > --------+---------+-----------+---------+------------- > x | integer | | plain | > y | integer | | plain | > z | integer | | plain | > View definition: > SELECT t1.x, t1.y, t2.z > FROM t1 > JOIN t2 USING (x); > regression=# alter table t2 rename column x to q; > ALTER TABLE > regression=# \d+ v1 > View "public.v1" > Column | Type | Modifiers | Storage | Description > --------+---------+-----------+---------+------------- > x | integer | | plain | > y | integer | | plain | > z | integer | | plain | > View definition: > SELECT t1.x, t1.y, t2.z > FROM t1 > JOIN t2 USING (x); > > At this point the dumped view definition is wrong: if you try to execute > it you get > > regression=# SELECT t1.x, t1.y, t2.z > regression-# FROM t1 > regression-# JOIN t2 USING (x); > ERROR: column "x" specified in USING clause does not exist in right table > > I'm suggesting that we could fix this by emitting something that forces > the right alias to be assigned to t2.q: > > SELECT t1.x, t1.y, t2.z > FROM t1 > JOIN t2 AS t2(x,z) > USING (x);
Sneaky. I didn't know that would even work, but it seems like a sensible approach. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
