Referencing subselect returned value
I'd like to reference values returned by a subselect in the same SELECT
query.
Example:
SELECT id,
( SELECT COUNT(*) FROM second ) AS value_to_reference,
( value_to_reference + 1 ) AS value_that_uses_referenced_one
FROM first;
Any suggestions?
Thank you,
Marco
On Tue, Jan 20, 2004 at 21:21:56 +0100,
Marco Lazzeri <marcomail@noze.it> wrote:
I'd like to reference values returned by a subselect in the same SELECT
query.Example:
SELECT id,
( SELECT COUNT(*) FROM second ) AS value_to_reference,
( value_to_reference + 1 ) AS value_that_uses_referenced_one
FROM first;Any suggestions?
If you want to use a subselect repeatedly, you can either repeat it or
join it. Doing a join will normally be better.
Repeated select example:
SELECT id,
( SELECT COUNT(*) FROM second) AS value_to_reference,
( SELECT COUNT(*) FROM second)+1 AS value_to_reference_one,
FROM first;
Join example:
SELECT id,
cnt AS value_to_reference,
cnt+1 AS value_reference_one,
FROM first, (select COUNT(*) AS cnt from second) AS third;