Using Table Variable Inside a Loop

Be careful when using a table variable inside a loop. If it's not cleared, the rows inside the table variable might accumulate after each iteration. It seems that in T-SQL, a variable declared inside a loop is not automatically re-initialised.

declare @counter integer = 0
while @counter < 10
begin
	declare @tableVar table (code integer)

    -- to test, comment out this line
	delete @tableVar -- need to clear otherwise previous results will accumulate
	
	insert into @tableVar values (@counter)
	
	select * from @tableVar
	
	set @counter = @counter + 1	
end