On 12/04/13 10:17, Craig James wrote:
> Hmmm.... the subselect is invalid, but not rejected. The outer select
> returns every row in the customer_order_matches table. This seems
> pretty wrong. This is PG 9.2.1 running on Ubuntu.
>
>
> db=> select count(1) from customer_order_matches where
> customer_order_item_id in (select customer_order_item_id from
> customer_order where customer_order_id = 105862140);
> count
> -------
> 36180
> (1 row)
>
> db=> select customer_order_item_id from customer_order where
> customer_order_id = 105862140;
> ERROR: column "customer_order_item_id" does not exist
> LINE 1: select customer_order_item_id from customer_order where cust...
> ^
>
> Craig
The "customer_order_item_id" in the subselect is referencing the
column and therefore the value of the outer query "customer_order_item_id"
in the query result.
i.e:
SELECT generate_series FROM generate_series(1,100) WHERE generate_series
IN (SELECT generate_series);
Which is always going to be true. (x == x).
You might want to explicitly reference tables (and alias). Such as:
SELECT count(*) FROM customer_order_matches com
WHERE com.customer_order_item_id IN
(SELECT co.customer_order_item_id
FROM customer_order co
WHERE co.customer_order_id = 105862140);
Although I'm making asumptions with the "customer_order_id".
Jules.