Query Variables

Hi,

I'm new to SQL Server, but an experienced .Net developer. I'm trying
to accomplish a query the most efficient way possible. My question is
if you can define a temporary variable within a query to store tables
or fields. (Like the LET clause of LINQ) My query makes use of
subqueries which filter my table (WHEREs, not SELECTs) in the same
exact way. I'd like to have a subquery at the beginning of my query
to filter the table(s) once, and then SELECT off it of later in the
query.

Here is an (utterly poor) example. No, this is not from my project.
My filter is a little more complex than 'c=@.p'.
('c' is a column/field, 't' is a table', '@.p' is a parameter)

SELECT *
FROM (SELECT COUNT(c) FROM t WHERE c=@.p GROUP BY c)
CROSS JOIN (SELECT c FROM t WHERE c=@.p)

Bottom line, would something like the following be possible?

@.v = (SELECT c FROM t WHERE a=@.p)
SELECT *
FROM (SELECT COUNT(c) FROM @.v GROUP BY c)
CROSS JOIN (SELECT c FROM @.v)

I'd like to know if this is possible within a query, but I can move to
a Stored Procedure if I must. (I'll still need help then.)

Thank you all>My question is if you can define a temporary variable within a query to >store tablesor fields. (Like the LET clause of LINQ).

The answer is of course! Jump in anywhere and you will see what makes
sense:) You can start here:
http://beyondsql.blogspot.com/2007/...-variables.html
best,.
www.beyondsql.blogspot.com|||steve wrote:

Quote:

Originally Posted by

Quote:

Originally Posted by

>My question is if you can define a temporary variable within a query to >store tablesor fields. (Like the LET clause of LINQ).

>
The answer is of course! Jump in anywhere and you will see what makes
sense:) You can start here:
http://beyondsql.blogspot.com/2007/...-variables.html
>
best,.
www.beyondsql.blogspot.com

Posting only to discuss one's own product is one of the ten early
warning signs of crankery.|||On Oct 17, 11:51 am, Ed Murphy <emurph...@.socal.rr.comwrote:

Quote:

Originally Posted by

steve wrote:

Quote:

Originally Posted by

Quote:

Originally Posted by

My question is if you can define a temporary variable within a query to >store tablesor fields. (Like the LET clause of LINQ).

>

Quote:

Originally Posted by

The answer is of course! Jump in anywhere and you will see what makes
sense:) You can start here:
http://beyondsql.blogspot.com/2007/...les-are-typed-v...

>

Quote:

Originally Posted by

best,.
www.beyondsql.blogspot.com

>
Posting only to discuss one's own product is one of the ten early
warning signs of crankery.

If you had bothered to read the link you'd see it was exactly what the
op was asking for. I guess you can be an sql cop. I'm not so sure
about a detective :)