使用复合主键从另一个表中插入或更新表

Question

我要寻找正确的语法和方式做直接从SQL如下：插入或更新（如果数据已经内部存在）TableMain从包含在数据TableA与两者都具有相同的复合主键。

这两个表的定义为：

CREATE TABLE TableA (
[TID0] [int] NOT NULL,
[TID1] [int] NOT NULL,
[language] [nvarchar](2) NOT NULL,
[TID2] [nvarchar](200) NOT NULL,
[text] [nvarchar](max) NULL,
[updatedOn] [datetime] NOT NULL  DEFAULT (getdate())
PRIMARY KEY (
    [TID0],
    [TID1],
    [language],
    [TID2],
)
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]

TableA 将定期删除并填充。

TableMain因为相同的定义，但将包含数据的更多的行和我需要的是从插入从未见过值TableA入TableMain，并更新现有的行。

我曾经做过这种插入，但是我不知道如何处理更新和复合主键：

INSERT INTO TableMain 
    SELECT * FROM TableA

编辑：我正在使用 SQL Server 9.00.5000

编辑：另一种受MERGE启发并模仿它的方法

DECLARE @updatedIDs TABLE(
    [TID0] [int],
    [TID1] [int],
    [language] [nvarchar](2),
    [TID2] [nvarchar](200),
                PRIMARY KEY ([TID0], [TID1], [language], [TID2])  -- as stated by Nikola Markovinovi膰 above, thanks
);

-- First update records 
update TableMain 
   set [text]      = source.[text], 
       [updatedOn] = source.[updatedOn] 
       OUTPUT
         inserted.[TID0]
         inserted.[TID1]
         inserted.[language]
         inserted.[TID2]
       INTO @updatedIDs
  from 
       TableMain AS main
       , TableA AS source 
  WHERE    
   TableMain.[TID0]         = source.[TID0] 
   and TableMain.[TID1]     = source.[TID1] 
   and TableMain.[language] = source.[language] 
   and TableMain.[TID2]     = source.[TID2]

-- And then insert

insert into TableMain
select *
  from TableA AS source 
 where not exists 
       ( 
      select 1
        from @updatedIDs AS i
       where i.[TID0]     = source.[TID0] 
         and i.[TID1]     = source.[TID1] 
         and i.[language] = source.[language] 
         and i.[TID2]     = source.[TID2] 
       )

Answer 1

这是您可以用来添加数据的脚本：

-- On error transaction is automatically rolled back
set xact_abort on

begin transaction
-- First update records
update TableMain
   set [text]      = source.[text],
       [updatedOn] = source.[updatedOn]
  from TableMain
 inner join TableA source
    on TableMain.[TID0]     = source.[TID0]
   and TableMain.[TID1]     = source.[TID1]
   and TableMain.[language] = source.[language]
   and TableMain.[TID2]     = source.[TID2]

-- And then insert

insert into TableMain ([TID0], [TID1], [language], [TID2], [text], [updatedOn])
select [TID0], [TID1], [language], [TID2], [text], [updatedOn]
  from TableA source
 where not exists
       (
          select *
            from TableMain
           where TableMain.[TID0]     = source.[TID0]
             and TableMain.[TID1]     = source.[TID1]
             and TableMain.[language] = source.[language]
             and TableMain.[TID2]     = source.[TID2]
       )

commit transaction

您可能会改写not exist（），left join ... where TableMain.TID0 is null好像性能并不令人满意。