SQL Server：MERGE导致无法将值NULL插入列答案

【问题标题】：SQL Server : MERGE causing cannot insert the value NULL into columnSQL Server：MERGE导致无法将值NULL插入列
【发布时间】：2017-05-06 09:45:59
【问题描述】：

我正在使用以下代码在 SQL Server 中执行MERGE（请原谅我，但我是新手，我无法弄清楚如何通过复制和粘贴正确缩进和格式化我的代码）：

MERGE INTO DW_Datawarehouse.[dbo].[DWF_WAREHOUSE] with (HOLDLOCK) AS target
USING #DataSource AS Source 
      ON target.[DWF_WAREHOUSE_ORDER_NUM] = source.[DWF_WAREHOUSE_ORDER_NUM]
         AND target.DWF_WAREHOUSE_ORDER_TYPE_CD = source.DWF_WAREHOUSE_ORDER_TYPE_CD

WHEN MATCHED AND 
      (
      --all non-key fields, attributes and amounts
        source.[DWF_WAREHOUSE_ORDER_DESC] <> target.[DWF_WAREHOUSE_ORDER_DESC]
        or source.[DWF_WAREHOUSE_PICK_DATE_DAY] <> target.[DWF_WAREHOUSE_PICK_DATE_DAY]
        or source.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM] <> target.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM]
        or source.[DWF_WAREHOUSE_DIFF_QTY] <> target.[DWF_WAREHOUSE_DIFF_QTY]
        )
   THEN 
      UPDATE  
      SET target.[DWF_WAREHOUSE_ORDER_DESC] = source.[DWF_WAREHOUSE_ORDER_DESC],
          target.[DWF_WAREHOUSE_PICK_DATE_DAY] = source.[DWF_WAREHOUSE_PICK_DATE_DAY],
          target.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM] = source.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM],
          target.[DWF_WAREHOUSE_DIFF_QTY] = source.[DWF_WAREHOUSE_DIFF_QTY]

WHEN NOT MATCHED BY TARGET THEN
    INSERT ([DWF_WAREHOUSE_ORDER_DESC], [DWF_WAREHOUSE_PICK_DATE_DAY],
            [DWF_WAREHOUSE_DAY_OF_WEEK_NUM], [DWF_WAREHOUSE_DIFF_QTY])
    VALUES (source.[DWF_WAREHOUSE_ORDER_DESC], source.[DWF_WAREHOUSE_PICK_DATE_DAY],
            source.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM], source.[DWF_WAREHOUSE_DIFF_QTY])

WHEN NOT MATCHED BY SOURCE THEN
    DELETE;

我收到错误：

无法将值 NULL 插入“DWF_WAREHOUSE_ORDER_NUM”列，表 'DW_Datawarehouse.dbo.DWF_WAREHOUSE';列不允许空值。更新失败。

如何修改我的MERGE 代码以避免此错误？

【问题讨论】：

trigger 是否在 DWF_WAREHOUSE 表上。您当前的Merge 查询不会产生此错误
表示需要为DWF_WAREHOUSE_ORDER_NUM列指定一个值。您的INSERT 声明不包含此列。

标签： sql-server merge insert null sql-insert

【解决方案1】：

听起来数据源中的 DWF_WAREHOUSE_ORDER_NUM 为空。您可以将数据源更改为

SELECT * FROM #DataSource AS WHERE DWF_WAREHOUSE_ORDER_NUM IS NOT NULL

例子：

MERGE INTO DW_Datawarehouse.[dbo].[DWF_WAREHOUSE] with (HOLDLOCK) as target
  USING
(SELECT * FROM #DataSource AS WHERE DWF_WAREHOUSE_ORDER_NUM IS NOT NULL)AS Source

  ON target.[DWF_WAREHOUSE_ORDER_NUM] = source.[DWF_WAREHOUSE_ORDER_NUM]
  AND target.DWF_WAREHOUSE_ORDER_TYPE_CD = source.DWF_WAREHOUSE_ORDER_TYPE_CD

WHEN MATCHED AND 
  (
  --all non-key fields, attributes and amounts
    source.[DWF_WAREHOUSE_ORDER_DESC] <> target.[DWF_WAREHOUSE_ORDER_DESC]
    or source.[DWF_WAREHOUSE_PICK_DATE_DAY] <> target.[DWF_WAREHOUSE_PICK_DATE_DAY]
    or source.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM] <> target.[DWF_WAREHOUSE_DAY_OF_WEEK_NUM]
    or source.[DWF_WAREHOUSE_DIFF_QTY] <> target.[DWF_WAREHOUSE_DIFF_QTY]
    )
.....

【讨论】：