Stored Procedures - Using Return Value From Dynamically Created SQL Statement

Hello,

This is my foray into Stored procedures, so I'm hoping this is a fairly basic question.

I'm writing a stored procedure, in which I dynamically create an SQL statement.
At the end of this, the SQL statement reads like:



Code SnippetSELECT COUNT(*) FROM StockLedger WHERE StockCode = 'STOCK1' AND IsOpen = 1 AND SizeCode = 'L' AND ColourCode = 'RED' AND LocationCode IS NULL AND RemainingQty > 0



Now this statement works a charm, and returns a single value. I want to assign this count to a variable, and use it further on in the stored procedure. This is where the problems start - I cant seem to do it.

If I hard code a statement, like



Code SnippetSELECT @LineCount = COUNT(*) FROM StockLedger
that works fine (although it brings back a count of all the lines).

But if I modify the dynamically created SQL Statement from earlier on to:



Code SnippetSELECT @LineCount = COUNT(*) FROM StockLedger WHERE StockCode = 'STOCK1' AND IsOpen = 1 AND SizeCode = 'L' AND ColourCode = 'RED' AND LocationCode IS NULL AND RemainingQty > 0
it doesnt work - it complains: Must declare the scalar variable "@LineCount".

Just to clarify, when I say "dynamically created an SQL statement, I mean that by a bunch of conditional statements I populate a varchar variable with the statement, and then eventually run it exec(@SQLStatementString)

So, my question would be, how do I do this? How do I make a dynamically generated SQL statement return a value to a variable?