A subquery that assigns a value to the local variable can return only one value. Here are some examples:
declare @veryhigh money select @veryhigh = max(price) from titles if @veryhigh > $20 print "Ouch!" declare @one varchar(18), @two varchar(18) select @one = "this is one", @two = "this is two" if @one = "this is one" print "you got one" if @two = "this is two" print "you got two" else print "nope" declare @tcount int, @pcount int select @tcount = (select count(*) from titles), @pcount = (select count(*) from publishers) select @tcount, @pcount
