Question : Combine data from several rows into a single result

Hi Experts,

I have something that has been puzzling me for days.

I've got a SPROC that queries one or two tables and returns rows appropriately and as expected.

The problem is that I now need to query a single column in a different table which may have up to four rows. I want to concatenate the values from the four rows and return them as one column in the existing SPROC.

I thought of declaring a local variable and updating it with a correlated sub-query and returning that as a single value in the select statement in my main sproc. However SqlServer says that I can't mix the update with the select.

What's the best strategy for this kind of thing? Any help would be very much appreciated.

Answer : Combine data from several rows into a single result

Try this...

SELECT CITY, COUNT(ID) AS TOTALREGISTERED, SUM(CASE WHEN ATTENDED='Y' THEN 1 ELSE 0 END) as TOTALATTENDED FROM REGISTRATIONS GROUP BY CITY ORDER BY CITY