RAISERROR中的连接消息

Question

这里的正确语法是什么？

If (@timestamp < (Select PromoStartTimestamp From @promo))
    RAISERROR('Code not valid until ' + (Select PromoStartTimestamp From @promo)
              ,16
              ,1);

我试过了：

If (@timestamp < (Select PromoStartTimestamp From @promo))
    RAISERROR(N'Code not valid until @starttimestamp'
              ,16
              ,1
              ,(Select PromoStartTimestamp From @promo));

Answer 1

在RAISERROR中，可以将%s用作字符串替换参数

DECLARE @PromoStartTimestamp DATETIME
DECLARE @PromoStartTimestampString VARCHAR(50)

SELECT @PromoStartTimestamp = PromoStartTimestamp From @promo
SELECT @PromoStartTimestampString = CAST(@PromoStartTimestamp AS VARCHAR)

If (@timestamp < @PromoStartTimestamp)
    RAISERROR(N'Code not valid until %s'
              ,16
              ,1
              ,@PromoStartTimestampString);