Re: How to use an alias name in the current select

Hi,

Guy Deleeuw <G(dot)De_Leeuw(at)eurofer(dot)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,
--
dim