Question

Suppose I’m trying to construct a SQL query to find all people that haven’t made a sale since 6/1/2012 and I have 2 tables:

UserID    FirstName    LastName
1000      Ted          Ting
1001      Sally        Song
1002      Adam         Apple

UserID   SalesDate
1000     8/1/2012
1000     6/12/2012
1000     6/11/2012
1000     5/3/2012
1001     3/1/2012
1001     5/30/2012
1002     6/15/2012
1002     5/1/2011

The result of this query would contain columns:

UserID   FirstName   LastName  LastSalesDate
1001     Sally       Song      5/30/2012

Notice that this just returns Sally’s latest sale, not all sales that were before the date (it doesn’t show the sale on 3/1/2012). What is the right SQL query to get this?

Answer 1

SELECT t1.UserID, t1.FirstName, t1.LastName, MAX(SalesDate) AS SalesDate
FROM Table1 t1 JOIN Table2 t1 ON t1.UserId = t2.UserID
GROUP BY t1.UserID, t1.FirstName, t1.LastName
HAVING MAX(SalesDate) < '20120601'