在 Merge 语句方面需要帮助

Question

我想从名为 Sorels 的表中更新名为 Sorels_ext 的表。它们之间的联系是 Sorels_ext 的 fkey_id 等于 Sorels 表的 identity_column。这是我第一次尝试 Merge 语句，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：在 MERGE 语句中使用的插入列列表不能包含多部分标识符。请改用单部分标识符。 55 0

********添加了更多信息****** 根据建议调整后，我有以下几点：

    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);

我得到错误：

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

我做错了什么？

**** 我明白了！！！ *****

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) 

应改为：

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，也不知道如何解决它。

如果它看到“column1”，它就知道它属于目标表。它看到“table1.column1”，它不知道“table1”是什么意思，因为“table1”作为标记超出了范围。

Answer 2

我相信您必须像这样为您的源数据起别名：

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)

Answer 3

尝试去掉“) AS SOR”中的“AS”