use School --指定數據庫
declare @min_id int --聲明整數變量@x
set @min_id=(select MIN(Id) from Students) --給變量@x賦初值為當前最小的Id值
while @min_id>0
begin
update Students set Age=ROUND(RAND()*100,0) where Id=@min_id --round()四舍五入把原值轉化為指定小數位數
--rand()取得是隨機數 默認范圍為(0·1) rand()*100范圍是0~100
select @min_id=(select MIN(Id) from Students where Id>@min_id)
end

