Question

伙计们我有这样的事情：

select  t1.milestone_id, sum(t2.value) / count(t2.value) as value2, value3
from    (
            SELECT  milestone_id, SUM(value) value , CASE WHEN (status !='done') THEN (value ='0') ELSE value END as value3
            FROM    project_has_tasks
            WHERE   project_id='52' and milestone_id !=0 
            GROUP BY milestone_id
        ) t1
join    (
            SELECT  milestone_id, SUM(value) value
            FROM    project_has_tasks
            WHERE   project_id='52' and milestone_id !=0 
            GROUP BY milestone_id
        ) t2
on      t1.milestone_id >= t2.milestone_id
group by t1.milestone_id
order by t1.milestone_id asc

得到了这个： enter image description here

请你帮我把value3作为value2除了0 像这样：

enter image description here

感谢您的任何建议。

Answer 1

修改你的第一行：

SELECT t1.milestone_id, sum(t2.value) / count(t2.value) as value2, IF(value3=0, sum(t2.value) / count(t2.value), value3) as value3

IF语句适用于以下(see the doc)：

IF(<expression>, <expression is true>, <expression is false>)

如果expression不是NULL而不是0则认为是真的。

Answer 2

感谢您的建议。下面的代码很好用：）

select  t1.milestone_id, sum(t2.value) / count(t2.value) as value2, IF(value3 !='0', sum(t2.value) / count(t2.value), value3)as value3
    from    (
                SELECT  milestone_id, SUM(value) value , CASE WHEN (status !='done') THEN (value ='0') ELSE value END as value3
                FROM    project_has_tasks
                WHERE   project_id='52' and milestone_id !=0 
                GROUP BY milestone_id
            ) t1
    join    (
                SELECT  milestone_id, SUM(value) value
                FROM    project_has_tasks
                WHERE   project_id='52' and milestone_id !=0 
                GROUP BY milestone_id
            ) t2
    on      t1.milestone_id >= t2.milestone_id
    group by t1.milestone_id
    order by t1.milestone_id asc

情况下，选择MYSQL

2 个答案: