如果需要，请选择MYSQL

伙计们，我有这样的东西：

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 

得到这个：

您能帮我将值3作为除0以外的值2获取吗 例如：

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 

---

谢谢您的建议。

修改您的第一行：

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语句的工作原理如下：

IF（，）

---

若表达式不为NULL且不为0，则视为真。

谢谢您的建议。下面的代码工作正常：）

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#1054-字段列表中的未知列“value2”忘记了计算value2如果我将使用：选择t1.milestone_id，总和（t2.value）/计数（t2.value）作为value2，如果（value3=0，总和（t2.value）/计数（t2.value），值3作为值3，则值3与值2相同

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