WHILE的寫法比CUSOR不耗資源，若使用的變數不多，建議使用
--讀取帶年月的TABLE
IF OBJECT_ID('tempdb..#T') is not null
DROP TABLE #T
create table #T (sn int identity(1,1),ym varchar(8))
insert into #T (ym)
select '202001'
union select '202002'
union select '202003'
declare @YM as varchar(6)
declare @i as int = 1
while @i <= (select max(sn) from #T)
begin
set @YM = (select ym from #T where sn=@i)
exec('SELECT * FROM TAB_'+ @YM +'')
set @i+=1
end