从具有复合主键的另一个表插入或更新表

我正在寻找正确的语法和方法来直接从 SQL 执行以下操作：插入或更新（如果数据已存在）TableMain从包含的数据TableA两者具有相同的复合主键。

两个表都定义为：

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将定期删除和填充。

TableMain与相同的定义相同，但将包含更多行数据，我需要的是插入从未见过的值TableA into TableMain，并更新已经存在的行。

我曾经做过这种插入，但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：受 MERGE 启发的另一种方式和模仿它 http://sqlserver-tips.blogspot.fr/2006/09/mimicking-merge-statement-in-sql.html

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

你应该使用merge http://technet.microsoft.com/pt-br/library/bb510625.aspx声明

像这样的东西：

merge TableMain  AS target
using TableA as source 
ON <join tables here>
WHEN MATCHED THEN <update>
WHEN NOT MATCHED BY TARGET <Insert>
WHEN NOT MATCHED BY SOURCE <delete>