SQLServer對(duì)select語(yǔ)句返回多條記錄給變量賦值時(shí)的處理情況

declare @user nvarchar(20)
    select @user='user1'
    use countme
    /*判斷用戶(hù)是否存在*/
    declare @userweek int
    select @userweek=[week] from base where userid=@user
    select @@rowcount
    if @@rowcount=0
    return
    select @userweek
    最后的@userweek打印出來(lái)的結(jié)果就是記錄用戶(hù)名為user1的week字段的值
    而當(dāng)我們用下面的語(yǔ)句選擇所有記錄時(shí)(沒(méi)有where限制)
    declare @user nvarchar(20)
    select @user='user1'
    use countme
    /*判斷用戶(hù)是否存在*/
    declare @userweek int
    select @userweek=[week] from base
    select @@rowcount
    if @@rowcount=0
    return
    select @userweek