Re: sub-select parameter problem

>
> Hello,
>
> Imagine the following query:
>
> -------------------------------------------
> SELECT
>
> tableA.field1,
> tableA.field2,
> =20=20
> tableB.field1,
> tableB.field2,
>
> (
> SELECT tableC.field2
> FROM tableC
> WHERE tableC.field1 =3D tableB.field1 - 1;
> ) AS p
>
> FROM tableA
> INNER JOIN tableB
> ON tableA.pk =3D tableB.FK;
> -------------------------------------------
>
> It works fine.
>
> Now, I need to do something else: the parameter of my sub-select is also
> a member of the table I'm selecting.
>
> -------------------------------------------
> SELECT
>
> tableA.field1,
> tableA.field2,
> =20=20
> tableB.field1,
> tableB.field2,
>
> (
> SELECT tableB.field2
> FROM tableB
> WHERE tableB.field1 =3D tableB.field1 (--> from-main-select?) - 1;
> ) AS p
>
> FROM tableA
> INNER JOIN tableB
> ON tableA.pk =3D tableB.FK;
> -------------------------------------------
>
> How can I refer to the tableB.field1 parameter from the main query? I've
> tried to do something like this, but without success:
>
[snip]
If the tableC example works fine - this should do too
SELECT
tableA.field1,
tableA.field2,
tableB.field1,
tableB.field2,
( SELECT tB.field2
FROM tableB tB
WHERE tB.field1 = tableB.field1 - 1;
) AS p
FROM tableA
INNER JOIN tableB
ON tableA.pk = tableB.FK;

HTH

Regards, Christoph