Question

   select case when exists(
                              select top 1 1 
                              from dg_world_records wr (nolock) 
                              where wr.gametypeid = 4 
                              and wr.playerid = 1
                           ) 
    then totaltime = (select min(totaltime) from dg_world_records (nolock) where playerid = 1 and gametypeid = 4)
    else totaltime = (select max(totaltime) from dg_world_records (nolock) where gametypeid = 4)
    end

我的猜测是，这是无法完成的，但我正在尝试在sql case语句中进行子选择。这可能吗？

我正在尝试根据查找或未在表中查找值进行查找。我可以通过分解声明来做到这一点，但我想知道是否可以在一个声明中做到这一点。

以下是表架构：

CREATE TABLE [dbo].[DG_WORLD_RECORDS](
[WorldRecordId] [int] IDENTITY(1,1) NOT NULL,
[GameTypeId] [int] NOT NULL,
[PlayerId] [int] NOT NULL,
[NumberOfValues] [int] NOT NULL,
[TotalTime] [int] NOT NULL,
[DateOfRecord] [datetime] NOT NULL,
[GameId] [int] NULL,
[UTCInserted] [datetime] NOT NULL CONSTRAINT [DF_DG_WORLD_RECORDSII_UTCInserted]  DEFAULT (getutcdate()),
[UTCUpdated] [datetime] NOT NULL CONSTRAINT [DF_DG_WORLD_RECORDSII_UTCUpdated]  DEFAULT (getutcdate()),
[SrvName] [varchar](30) COLLATE SQL_Latin1_General_CP1_CI_AS NOT NULL CONSTRAINT [DF_DG_WORLD_RECORDSII_SrvName]  DEFAULT (@@servername),

CONSTRAINT [PK_DG_WORLD_RECORDS] PRIMARY KEY CLUSTERED （ [WorldRecordId] ASC ））

Answer 1

不知道你为什么写这个疯狂的查询，但回答你的问题，是的，它可以完成，只需将你的作业移出案例陈述：

select totaltime = CAST (
   case when exists(
     select * 
     from dg_world_records wr (nolock) 
     where wr.gametypeid = 4 and wr.playerid = 1) 
    then (select min(totaltime) from dg_world_records (nolock) where playerid = 1 and gametypeid = 4)
    else (select max(totaltime) from dg_world_records (nolock) where gametypeid = 4)
    end AS INT)

带有Subselect的SQL Case语句

1 个答案: