DB2，使用内部的case语句获取平均值

Question

在DB2中，我试图在GROUP BY中获取不同的字段，同时也在每行中获取特定值的平均值。

我认为问题在于我正在尝试在AVG子句中使用CASE

所以它说'AS'不应作为令牌，我认为它在AVG中我的第一个CASE中。

所以：

 SELECT
    number,
    customer,
    group,
    groupDetail,
    category,
    detail,
    detailName,
    avg(countOfSales),
    avg(annuals),
    avg(case when trajectory is null then 0 else trajectory end as trajectory),
    avg(annualsLocation),
    avg(case when trajLocation is null then 0 else trajLocation end as trajLocation),
    avg(annualsWhole),
    avg(case when trajWhole is null then 0 else trajWhole end as trajWhole)
FROM salesReporting
WHERE customer = 123
group by number,customer,group,groupDetail,category,detail,detailName
ORDER BY customer,groupDetail,category,detail ASC

我想要

customer | group | groupDetail | category | detail | detailName | countOfSales | annuals | trajectory | annualsLocation | trajLocation | annualsWhole | trajWhole
---------------------------------------------------------------------------------------------------------------------------------------------------------------------
123         1         Atl.          Sls       New       NewLoc      12345           2948     124.84       8372                246.08        8372         28.84
123         1         Atl.          Sls       New       NewLoc      12345           2345     164.84       4839                234.08        4839         26.63
123         1         Atl.          Sls       New       NewLoc      12345           6523     224.84       2345                654.08        2345         29.85
123         1         Atl.          Sls       New       NewLoc      12345           3456     134.84       5434                152.08        5434         25.34
123         1         Atl.          Sls       New       NewLoc      12345           3426     124.84       6234                245.08        6234         28.84

如何在DB2中正确实现？

Answer 1

这是一个语法问题，别名“轨迹应在avg括号之外

例如：

avg(case when trajectory is null then 0 else trajectory end) as trajectory

Answer 2

使用coalesce()可以更简单地编写此逻辑：

avg(coalesce(trajectory, 0)) as trajectory,
. . .