Question

我有一个有效的查询，但是我试图使用列别名以便在我的选择中创建更多计算，并且它说找不到该列（即它不能使用别名）。

例如，工作查询：

select employee,
       sum(case when date_field between '2018-01-01' and '2018-01-31' and category = 'CategoryOne' then salesprice else 0 end) as priorDate,
       sum(case when date_field between '2018-01-01' and '2018-01-31' then salesprice else 0  end) as priorTotal,
       cast(Round((DEC(sum(case when date_field between '2018-01-01' and '2018-01-31' and category = 'CategoryOne' then salesprice else 0 end),12,2)/sum(case when date_field between '2018-01-01' and '2018-01-31' then salesprice else 0  end)) * 100,2) as decimal(12,2)) as priorPercent,
       sum(case when date_field between '2019-01-01' and '2019-01-31' and category = 'CategoryOne' then salesprice else 0 end) as currentDate,
       sum(case when date_field between '2019-01-01' and '2019-01-31' then salesprice else 0 end) as currentSales,
       cast(Round((DEC(sum(case when date_field between '2019-01-01' and '2019-01-31' and category = 'CategoryOne' then salesprice else 0 end),12,2)/sum(case when date_field between '2019-01-01' and '2019-01-31' then salesprice else 0  end)) * 100,2) as decimal(12,2)) as currentPercent
from table
group by employee;

但是对于我的两个百分比（以强制转换开头的两行），我尝试仅使用priorDate / priorTotal，但是它不起作用，因此我必须将整个2个计算重复一个百分比。

我还想获得百分比差异，通过使用别名来声明它会容易得多，也许性能更高？

Answer 1

您可以使用CTE /子查询编写此代码：

---
published: true
title: Embeded SVG
---
## title

<svg width="400" height=300>
    <circle cx="150" cy="100" r="10" fill="blue"/>
</svg>

在同一选择内使用DB2列别名

1 个答案: