Question

I am trying to run a SQL query (SQL Server) that will look up a list of names from a subquery.

I have this but I get a “subquery returned more than 1” error:

SELECT FirstName + ' ' + LastName AS Name
FROM Members
WHERE     
   (MemberGUID = (SELECT ClassDetails.Leader
                  FROM Members AS Members_1 
                  INNER JOIN MemberDetails ON Members_1.MemberGUID = MemberDetails.Member 
                  INNER JOIN ClassDetails ON ClassDetails.Class = Members_1.CurrentClass
                  WHERE      
                      (MemberDetails.JoiningDate >= '02/03/2012') 
                      AND (Members_1.FirstName = '*') 
                      OR (MemberDetails.JoiningDate >= '02/03/2012') 
                      AND (Members_1.LastName = '*') 
                      OR (MemberDetails.JoiningDate >= '02/03/2012') 
                      AND (MemberDetails.Email IS NULL) 
                      AND (MemberDetails.MobilePhone IS NULL) 
                      AND (MemberDetails.WorkPhone IS NULL) 
                      AND (MemberDetails.HomePhone IS NULL) 
                      AND (Members_1.CurrentClass <> 339) 
                      AND (Members_1.CurrentClass <> 696) 
                      AND (Members_1.CurrentClass <> 0)))

I need this to return the values FirstName and LastName for every value returned in the subquery. (The subquery returns a list of GUIDs which should be fed into the WHERE MemberGUID statement)

How can this be done?

Answer 1

Offhand, I would think you could just change MemberGUID = to MemberGUID IN.

As the error message states, your subquery is returning many rows, and you can’t compare a single value to a collection of many rows. But you can look for that value in those rows, which is exactly what the IN operator does.

MSDN Reference