Question

我有两张表Customer_staging和Customer。 customer_staging表包含字段customer_num，birth_date和birth_month，此表每天都会刷新。此表中的任何新附加记录都应更新到实际的Customer表中。此外，任何与birth_date和birth_month的值不匹配的记录都应更新到Customer表中。

我尝试了以下查询。

Select customer_num, birth_date, birth_month from Customer_Staging
EXCEPT
Select customer_num, birth_date, birth_month from Customer
INNER JOIN Customer_Staging ON Customer_Staging.customer_num = Customer.customer_num

我得到了我想要的结果，但是，我得到了更多的记录。我在查询的第二部分中添加了内部联接，认为结果集将限制在具有较少记录数的表中。 Customer_Staging表有3170条记录，其中Customer表目前只有40条记录。例如，如果我有5条记录在两者之间匹配，则结果集有3165条记录。但是，我想获得仅存在于Customer表中的记录的差异结果集。

有人可以帮忙吗？

Answer 1

嵌套选择：

Select DISTINCT customer_num, birth_date, birth_month from Customer_Staging
WHERE customer_num NOT IN (Select customer_num
                           From Customer)

查找两个SQL Server表之间的数据差异

1 个答案: