Mysql 从两个表中计算剩余的货物库存

我有两张桌子
1.表中的事务处理：

+-----+
|id_in|
+-----+
| 2   |
| 2   |
| 1   |
| 3   |
| 2   |
| 3   |
+-----+

2.表事务输出：

+------+
|id_out|
+------+
|   2  |
|   2  |
|   3  |
|   1  |
+------+

我想做一个查询，以便根据类型在两个表之间产生差异 其中，每行的数量由行计数（*）确定 结果是

查询结果表

+--+---------------+----------------+----------------+
|id|count row id_in|count row id_out|(rowin - rowout)|
+--+---------------+----------------+----------------+
|1 |      1        |      1         |     0          | 
|2 |      3        |      1         |     2          |  
|3 |      2        |      2         |     1          |  
+--+---------------+----------------+----------------+

如何查询？

您可以在下面尝试-

select idin, count_idin, count_idout,  count_idin-count_idout as result
from
(
  select idin,count(idin) count_idin from transactionin group by idin
)A inner join 
(
  select idout,count(idout) count_idout from transactionout group by idout
)B on A.idin=B.idout

---

请参阅-在每种情况下，不要忘记识别主键谢谢您的解决方案，它很简单，：）@fami