需要有关Merge语句的帮助

Question

我想从名为Sorels的表中更新名为Sorels_ext的表.它们之间的链接是Sorels_ext的fkey_id等于Sorels表的identity_column.这是我在Merge语句中的第一次尝试,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);

当我运行它时,我收到以下错误:

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

***添加信息******

建议第一次修复后,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);

现在我收到以下错误:

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.请改用单个部件标识符.55 0

*******添加更多信息******经过建议调整后,我有以下内容:

    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);

我收到错误:

错误10/22/2009 2:46:51 PM 0:00:00.000 SQL Server数据库错误:列名称'FPARTNO'无效.56 0

我究竟做错了什么？

****我知道了!!!*****

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);

Answer 1

INSERT (SORe.fkey_id, SORe.Color) 

应该读:

INSERT (fkey_id, Color) 

插入列表中的列只能引用目标表.解析器不希望在那里看到表别名,并且不知道如何解决它.

如果它看到"column1",它知道它属于目标表.它看到"table1.column1",它不知道"table1"的意思,因为"table1"作为一个标记超出了范围.

Answer 2

我相信你必须像这样为你的源数据别名：

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) **AS SOR** ON  (SORe.fkey_id = SOR.identity_column)