use AdventureWorks;
go

declare @one_or_more table 
(
	DepartmentID smallint, 
	[Name] nvarchar(50)
);
declare @void table (DepartmentID smallint, [Name] nvarchar(50));

-- insert 10 records into @one_or_more and leave @void empty
insert into @one_or_more 
select 
	top 10 DepartmentID, [Name] 
	from HumanResources.Department;

select count(*) RecordCount, min(A.DepartmentID) DepartmentID
	from @one_or_more A, @void B;
go

RecordCount DepartmentID
----------- ------------
0           NULL