使用重复密钥更新的insert into的SQL查询

我有两个表

debitTable

和

creditTable

debitTable

具有以下记录：

+----+-------+
| id | debit |
+----+-------+
| a  | 10000 |
| b  | 35000 |
+----+-------+

而

creditTable

有以下记录：

+----+--------+
| id | credit |
+----+--------+
| b  | 5000   |
+----+--------+

如何使用SQL Server查询来生成以下结果：

+----+----------------+--------------+
| id | debit | credit | debit-credit |
+----+----------------+--------------+
| a  | 10000 |   0    |     10000    |
| b  | 35000 |  5000  |     30000    |
+----+-------+--------+--------------+

你可以试试“左加入”

你可以试试“左加入”

---

您想使用

连接

。但是，重要的是在加入之前进行聚合：

select coalesce(d.id, c.id) as id, coalesce(credit, 0) as credit,
       (coalesce(debit, 0) - coalesce(credit, 0)) as DebitMinusCredit
from (select id, sum(debit) as debit
      from debit
      group by id
     ) d full outer join
     (select id, sum(credit) as credit
      from debit
      group by id
     ) c
     on d.id = c.id;

---

这将使用

完全外部联接

来确保包括两个表中的所有记录，即使其中一个表中没有id。加入前的聚合是为了避免在两个表中的单个id都有多行时出现笛卡尔积。

要使用

加入

。但是，重要的是在加入之前进行聚合：

select coalesce(d.id, c.id) as id, coalesce(credit, 0) as credit,
       (coalesce(debit, 0) - coalesce(credit, 0)) as DebitMinusCredit
from (select id, sum(debit) as debit
      from debit
      group by id
     ) d full outer join
     (select id, sum(credit) as credit
      from debit
      group by id
     ) c
     on d.id = c.id;

select 
    debit.id, debit.debit, credit.credit, 
    debit.debit - credit.credit as [debit-credit]
from 
    debit 
left join 
    credit on debit.id = credit.id

这将使用

完全外部联接

来确保包括两个表中的所有记录，即使其中一个表中没有id。加入前的聚合是为了避免在两个表中的单个id都有多行时产生笛卡尔积

select 
    debit.id, debit.debit, credit.credit, 
    debit.debit - credit.credit as [debit-credit]
from 
    debit 
left join 
    credit on debit.id = credit.id

但这将只基于借方：这意味着，如果您在贷方中有id，而该id不在借方中，它将不会出现在该结果中

但这将只基于借方：这意味着，如果您在贷方中有id，而该id不在借方中，它将不会出现在该结果中