SQL Query Condition

Hi,

I am creating a stored procedure which takes a few paramaters. One of which is a string of comma separated codes. At the end of my select query the codes will be used in the where clause.

What I'm doing is parsing the comma separated string and populating a temp table called #codes. So my query will look something like this:

select * from tableA
where tableA.col1 = 'something'
and tableA.code in (select * from #codes)
and....

However, the code paramater can be null and if this is the case I want the query to be called for all codes - i.e. I effectively want to remove the and tableA.code in (select * from #codes) part of the where clause.

Is there any clever way of doin this other than having a if... else... and writing 2 queries - one with the and and one without it?

Hope this is clear.

Thanks,
Wallace