如何计算 2 个表之间的不同数量？

Question

我需要计算 2 table 秒之间的差异（来自 2 个不同日期的相同 table）以查看发生了什么变化。

例如table1:

table 2:

我想得到这个 table:

我试试这个代码：

select a.of_key , case when a.color != b.color then count (a.color) ELSE 0 END AS color,  
        case when a.side != b.side then count (a.side) else 0 end as side   
from 130720 A right JOIN 100720 B
ON a.of_key = b.of_key and a.num = b.bum
group by a.of_key

它不工作

请帮忙

谢谢！

Answer 1

将您的汇总放在 case 语句之外：

select a.of_key , SUM(case when a.color != b.color then 1 ELSE 0 END) AS color,  
        SUM(case when a.side != b.side then 1 else 0 end) as side   
from 130720 A right JOIN 100720 B
ON a.of_key = b.of_key and a.num = b.bum
group by a.of_key

如何计算 2 个表之间的不同数量？

how to count quantity of different between 2 tables?

sql-server

case

count

difference