SQL案例聲明與子選擇

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 

我的猜測是這不能完成，但我想在sql case語句中做一個子選擇。這可能嗎？

我試圖做基於發現或沒有找到在表中的值的查找。我可以通過分解聲明來做到這一點，但我想知道是否可以在一個聲明中做到這一點。

下面是表模式：

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), 

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

Answer 1

不知道您爲什麼要寫這個瘋狂的查詢，但要回答你的問題，是的，它可以做，只動分配出的情況下聲明：

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)