Record count should be null. Why 1?

I have a table that contains, among other things, customerid and orderid.

I need to get the last order that a customer made, if any. It's quite possible that they have never ordered.

I'm using the following SQL:
select max(orderid) as lastOrder from orders where customerid='#userid#';

If the customerid isn't in the table (never ordered before), I would expect a record count of 0 or null. However, I'm getting a record count of 1 with a value of [empty string] in lastOrder.

What gives?

I need to run another query if the customer has never ordered, but the other query isn't being run because the first one is finding a result.

Any ideas how I can do this differently or better?

Thanks,
G

Max and Min will return one row regards. You should try using count instead.

The following should return a single record with the maximum orderid or an empty recordset:

SELECT TOP 1 orderid AS lastOrder
FROM orders
WHERE customerid='#userid#'
ORDER BY orderid DESC

Ok. I like that solution.

My current solution is to test the result to make sure it's an INT, set a boolean, and switch on that.

It'll save a couple steps to just have a proper query.

Thanks all who answered!