Luca Pireddu wrote:
> Hello all. I'd like to write a query does a set subtraction A - B, but A is
> is a set of constants that I need to provide in the query as immediate
> values. I thought of something like
>
> select a from (1,2,3.4)
> except
> select col_name from table;
richardh=> SELECT * FROM foo;
a
---
1
2
3
(3 rows)
richardh=> SELECT * FROM foo WHERE a NOT IN (1,2);
a
---
3
(1 row)
Run some tests with nulls in the column and the constant list too so you
understand what happens in those cases.
--
Richard Huxton
Archonet Ltd