> Hi!
>
> I need some suggestions about a special query. The situation is:
>There are (for simplicity) 4 tables: A,B,C and D which must be joined
>like this:
> Between A and B must be an outer-join association and C and D must
>be connected to B also with outer-join.
>But this causes a 'Cross dependency found in OUTER JOIN' error. I could
>connect A and B with INNER JOIN but it's useless from my point of view.
>I think the problem could be solved with redesigning the database
>structure, but it's currently not possible.
You need to specify the outer join. A LEFT OUTER JOIN B is not the
same as A RIGHT OUTER JOIN B or B LEFT OUTER JOIN A. When you have
nested outer joins, only one of the tables can be preserved. You need
to specify which table is being preserved (all rows are returned).
I recommend posting the table definitions and stating which columns
are used in the joins.
> Does somebody know a good (general) solution for this? Temporary
>tables could help, but i deal with lot's of data and I'm afraid it would
>be very slow.
>
> Thanks!
>
> Christian Fischer
Outer joins + lot's of data = slow queries, even without temp tables.
Bob Hall
Know thyself? Absurd direction!
Bubbles bear no introspection. -Khushhal Khan Khatak
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