Question

我在加入两个计数语句时遇到了麻烦，最让我失望的是团队成员不同

SELECT COUNT(teamid) AS homescore FROM goals WHERE teamid = 1 AND gameid = 1
SELECT COUNT(teamid) AS awayscore FROM goals WHERE teamid = 2 AND gameid = 1

查询1结果

homescore
    0

查询2结果

awayscore
    0

我想要实现的目标

homescore | awayscore
    0     |     0

Answer 1

不确定你想要做什么，但也许这个：

SELECT COUNT(teamid) AS homescore FROM goals WHERE teamid = 1 AND gameid = 1
union
SELECT COUNT(teamid) AS awayscore FROM goals WHERE teamid = 2 AND gameid = 1

编辑：恢复列并处理空值。

select  nvl((SELECT COUNT(teamid) AS score FROM goals WHERE teamid = 1 AND gameid = 1),0) as homescore,
        nvl((SELECT COUNT(teamid) AS score FROM goals WHERE teamid = 2 AND gameid = 1),0) as awayscore
from dual

Answer 2

我认为这就是你要找的东西。

select 
sum(case when teamid = 1 then 1 else 0 end) as homescore,
sum(case when teamid = 2 then 1 else 0 end) as awayscore
from goals where gameid = 1

Answer 3

您应该使用内部联接或联合

SELECT COUNT（teamid）AS homescore FROM goals WHERE teamid = 1 AND gameid = 1 UNION SELECT COUNT（teamid）AS awayscore FROM goals WHERE teamid = 2 AND gameid = 1

内连接2计数语句

3 个答案: