Re: [HACKERS] Error in parser with UNIONS.
David Gould <dg@illustra.com>
From: dg@illustra.com (David Gould)
To: lockhart@alumni.caltech.edu (Thomas G. Lockhart)
Cc: chris@topdog.pas1.logicon.com, pgsql-hackers@hub.org
Date: 1998-05-31T05:29:43Z
Lists: pgsql-hackers
Tom Lane he say: > Made some progress: > > postgres=> select 1.2 as float8 union select 1; > float8 > ------ > 1 > 1.2 > (2 rows) > > postgres=> select text 'a' as text union select 'b'; > text > ---- > a > b > (2 rows) > > At the moment I'm forcing the types of the union to match the types of > the first/top clause in the union: > > postgres=> select 1 as all_integers > postgres-> union select '2.2'::float4 union select 3.3; > all_integers > ------------ > 1 > 2 > 3 > (3 rows) > > The better strategy might be to choose the "best" type of the bunch, but > is more difficult because of the nice recursion technique used in the > parser. However, it does work OK when selecting _into_ a table: > > postgres=> create table ff (f float); > CREATE > postgres=> insert into ff > postgres-> select 1 union select '2.2'::float4 union select 3.3; > INSERT 0 3 > postgres=> select * from ff; > f > ---------------- > 1 > 2.20000004768372 > 3.3 > (3 rows) > > Comments?? > Great stuff! -dg