Oleg Broytmann wrote:
>
> Hi!
>
> I am continuing playing with the query (I reduced it to):
> SELECT sh.distr_id , d.distr_id
> FROM central cn, shops sh, districts d
> WHERE cn.shop_id = sh.shop_id
>
> and got 27963 rows. I filtered it out (with awk:) where $1 == $2 (1st
> column is equal to second) and got 3104 rows.
>
> But the query
> SELECT d.*
> FROM central cn, shops sh, districts d
> WHERE cn.shop_id = sh.shop_id AND sh.distr_id = d.distr_id
>
> returned 0 rows.
>
> Where is the bug?
Please post me EXPLAIN VERBOSE for second query.
Vadim