SQL 服务器 : multiple WHERE NOT EXISTS clauses

Question

我在 Load_Charges_IMPORT 查询中有大约 2600 行未插入到 Load_Charges 查询中。

我试图确保没有添加重复的主键条目。主键在 Load_Charges 查询中建立为复合键(费用说明 + 费用金额)。 Load_Charges_IMPORT 查询中未设置键，此数据是从 excel 文档导入的。

你能告诉我我的代码是否有问题吗？当我知道 Load_Charges_IMPORT< 中有 2600 多行时，为什么我收到 0 row(s) affected 的响应.

INSERT INTO Load_Charges
    SELECT *
    FROM Load_Charges_IMPORT
    WHERE 
        NOT EXISTS (SELECT [Load ID]
                    FROM Load_Charges
                    WHERE Load_Charges_IMPORT.[Load ID] = Load_Charges.[Load ID])
        AND NOT EXISTS (SELECT [Charge Description]
                        FROM Load_Charges
                        WHERE Load_Charges_IMPORT.[Charge Description] = Load_Charges.[Charge Description])
        AND NOT EXISTS (SELECT [Charged Amount] 
                        FROM Load_Charges
                        WHERE Load_Charges_IMPORT.[Charged Amount] = Load_Charges.[Charged Amount]);

Answer 1

您的 EXISTS 子句排除了任何一个条件为真的所有行，而不仅仅是所有条件都为真的行。试试这个:

INSERT INTO Load_Charges

SELECT *

FROM Load_Charges_IMPORT

WHERE NOT EXISTS (
    SELECT * 
    FROM Load_Charges 
    WHERE Load_Charges_IMPORT.[Load ID]=Load_Charges.[Load ID]
    AND Load_Charges_IMPORT.[Charge Description]=Load_Charges.[Charge Description]
    AND Load_Charges_IMPORT.[Charged Amount]=Load_Charges.[Charged Amount]);