Sql 存储过程返回多个值

在执行此过程时，它会重新调用子查询返回的值超过1。当子查询在=、！=、=或者当子查询用作表达式时。

问题的直接原因是以下语句：

ALTER PROCEDURE [dbo].[sp_checktime]
( @Booking_Date date ,
    @Stime time(7) ,
    @Etime time(7) ,
    @Room varchar(50),
    @res int output
 )
AS
BEGIN
IF (@Stime=(select Start_Time from Booking_master where Booking_Date=@Booking_Date and Room=@Room) or @Stime>=(select Start_Time from Booking_master) and @Stime<=(select End_Time from Booking_master where Booking_Date=@Booking_Date and Room=@Room))
BEGIN
        set @res=0
END

ELSE    
    BEGIN
        set @res=1
    END

END

子查询似乎返回多行。自反修复是将其替换为in:

在你的情况下，我认为你最好修正逻辑，这样你只有一个逻辑，如果存在的话。陈述比如：

@Stime in (select Start_Time from Booking_master where Booking_Date=@Booking_Date and Room=@Room)

---

子查询只允许有一个结果。尝试将TOP1添加到每个子查询中，尽管问题可能与第二个子查询无关

if (exists (select 1
            from Booking_master bm
            where Booking_Date = @Booking_Date and Room = @Room and
                  (@Stime = Start_Time or
                   (@Stime >= StartTime and @Stime <= EndTime)
                  )
           )
   )

---

旁注：存储过程不应使用sp_uu前缀。微软已经这样做了，而且你确实有可能在将来的某个时候发生名称冲突。最好只是简单地避免使用sp_u，并使用其他东西作为前缀——或者根本不使用前缀！在子查询中添加前1。您的意思是Ifexistsy您的查询吗

if (exists (select 1
            from Booking_master bm
            where Booking_Date = @Booking_Date and Room = @Room and
                  (@Stime = Start_Time or
                   (@Stime >= StartTime and @Stime <= EndTime)
                  )
           )
   )

ALTER PROCEDURE [dbo].[sp_checktime]
( @Booking_Date date ,
    @Stime time(7) ,
    @Etime time(7) ,
    @Room varchar(50),
    @res int output
 )
AS
BEGIN
IF (
    @Stime = (select Top 1 Start_Time 
              from Booking_master 
              where Booking_Date=@Booking_Date and Room=@Room) 
 or @Stime >= (select Top 1 Start_Time 
               from Booking_master) 
and @Stime <= (select Top 1 End_Time 
               from Booking_master 
               where Booking_Date=@Booking_Date and Room=@Room))
BEGIN
        set @res=0
END

ELSE    
    BEGIN
        set @res=1
    END

END