Re: 2 tables, joins and same name...

Whew... a little complex. I think I know what you are trying to do.

First of all, try looking at the docs at the postgres site for UNION and also
for INTERSECT (both are found in "reference/sql commands/SELECT"). You might
not need either of these; your question isn't clear about what you want to do.

Maybe you just need to use OR instead of AND in your SQL. The SQL below
doesn't even look valid to me...

Try showing example table data and expected results (or maybe a simplified
version?). It is not clear exactly what results you are expecting for what
criteria you specify. It might be possible to simplify quite a bit.

Regards,
Jeff Davis

On Thursday 30 August 2001 01:26 pm, you wrote:
> Hello,
>
> Here is 2 tables:
>
> airport
> ---------
> airport_id
> name
> code
> city_id
>
> destination
> -----------
> destination_id
> dest_name
> ...
> airport_dep_id  // using airport.airport_id (departure)
> airport_arr_id  // using airport.airport_id  has well (arrival)
>
> I have 2 columns in the second table that uses the same name column in
> the first table...
>
> I dont know how to formulate my SQL query... I want to select the
> destinations in the destination table with not the ID of each airport
> but their names. I can do a join with one but with the second one, I get
> no results... And this is confusing!
>
> select dest.dest_name, air.name as airport1, air.name as airport2 from
> destination, airport air where dest.airport_dep_id_id=air.airport_id and
> dest.airport_arr_id=air.airport_id;
>
> This is not good...
>
> Any help?
>
> Thanks!