Re: How to use an alias name in the current select - Mailing list pgsql-admin

Hello Dimitri,

Many thanks for your answers

Regards
Guy

Le 24/03/10 20:09, Dimitri Fontaine a écrit :
> Hi,
>
> Guy Deleeuw<G.De_Leeuw@eurofer.be>  writes:
>
>>     SELECT
>>           t_orders_articles.k_id            AS k_id
>>          ,t_orders_articles.quantity        AS order_qty
>>          ,(SELECT sum(quantity) FROM t_deliveries_articles WHERE article_id =
>> t_orders_articles.k_id) AS delivery_qty
>>          , (t_orders_articles.quantity - delivery_qty)       AS qty
>>        FROM t_orders_articles
>>         ......;
>>
>> How can I make that without having 2 select call ?
>>
> Put it as a relation in a subquery, or use WITH if using 8.4.
>
> SELECT k_id, order_qty, quantity, delivery_qty,
>    quantity - delivery_qty as qty
>   FROM (
>      SELECT
>            t_orders_articles.k_id            AS k_id
>           ,t_orders_articles.quantity        AS order_qty
>           ,(SELECT sum(quantity) FROM t_deliveries_articles WHERE article_id =
>   t_orders_articles.k_id) AS delivery_qty
>           , t_orders_articles.quantity
>         FROM t_orders_articles
>        ) as t;
>
>
> Or
>
> WITH t AS (
>      SELECT
>            t_orders_articles.k_id            AS k_id
>           ,t_orders_articles.quantity        AS order_qty
>           ,(SELECT sum(quantity) FROM t_deliveries_articles WHERE article_id =
>   t_orders_articles.k_id) AS delivery_qty
>           , t_orders_articles.quantity
>         FROM t_orders_articles
> )
> SELECT k_id, order_qty, quantity, delivery_qty,
>    quantity - delivery_qty as qty
>    FROM t;
>
> Regards,
>