我想从一个名为Sorels的表更新一个名为Sorels_ext的表。它们之间的链接是Sorels_ext的fkey_id等于Sorels表的identity_column。这是我对Merge语句的第一次尝试，并且我正在尝试学习语法。

MERGE Sorels_ext AS SORe
USING (select SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END from Sorels AS SOR)
ON  (SORe.fkey_id = SOR.identity_column)

WHEN MATCHED THEN
  UPDATE SET SORe.fkey_id = SOR.identity_column, SORe.Color = select SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END
WHEN NOT MATCHED THEN
  INSERT (SORe.fkey_id, SORe.Color) VALUES (SOR.identity_column, SORe.Color = select SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END);

运行此命令时，出现以下错误：

错误10/22/2009 1:38:51 PM 0：00：00.000 SQL Server数据库错误：关键字’ON’附近的语法不正确。46 0

添加的信息*

在建议了第一个修复程序之后，代码如下：

    MERGE Sorels_ext AS SORe
USING (select SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END from Sorels) AS SOR
ON  (SORe.fkey_id = SOR.identity_column)

WHEN MATCHED THEN
  UPDATE SET SORe.fkey_id = SOR.identity_column, SORe.Color = CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END
WHEN NOT MATCHED THEN
  INSERT (SORe.fkey_id, SORe.Color) VALUES (SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END);

现在我得到以下错误：

错误10/22/2009 2:03:29 PM 0：00：00.000 SQL
Server数据库错误：MERGE语句中使用的插入列列表不能包含多部分标识符。请改用单个零件标识符。55 0

*添加了更多信息**从建议中进行调整后，我得到以下信息：

    MERGE Sorels_ext AS SORe
USING (select SOR1.identity_column, CASE
        WHEN left(SOR1.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR1.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END as colors from Sorels as SOR1 ) as SOR 
ON  (SORe.fkey_id = SOR.identity_column)

WHEN MATCHED THEN
  UPDATE SET SORe.fkey_id = SOR.identity_column, SORe.Color = CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END
WHEN NOT MATCHED THEN
  INSERT (fkey_id, Color) VALUES (SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END);

我得到了错误：

错误10/22/2009 2:46:51 PM 0：00：00.000 SQL Server数据库错误：无效的列名’FPARTNO’。56 0

我究竟做错了什么？

* 我得到了它！！！**

MERGE Sorels_ext AS SORe
USING (select SOR.identity_column, CASE
        WHEN left(SOR.FPARTNO, 2) = 'BL' THEN 'Blue'
        WHEN left(SOR.FPARTNO, 2) = 'RD' THEN 'Red'
        ELSE 'White'
      END as colors from Sorels as SOR) SOR1  
ON  (SORe.fkey_id = SOR1.identity_column)

WHEN MATCHED THEN
  UPDATE SET SORe.fkey_id = SOR1.identity_column, SORe.Color = SOR1.colors
WHEN NOT MATCHED THEN
  INSERT (fkey_id, Color) VALUES (SOR1.identity_column, SOR1.colors);