修改查询以根据特定列检查组内的多个值

Posted 2023-04-18

【中文标题】修改查询以根据特定列检查组内的多个值

【英文标题】：Amend Query To Check For Multiple Values Within A Group Based On Specific Column

【发布时间】：2019-08-02 09:57:38

【问题描述】：

我有来自外部系统的下表（数据是匿名的）：

我使用以下查询按列cola、colb 和colc 的组合对结果进行分组；并且 case 语句将 weekday 列中的 x 值替换为 amount 列中的相应值。这很好用。

SELECT
cola, 
colb, 
colc,
max(case when Mon = 'x' THEN amount END) as Mon,
max(case when Tue = 'x' THEN amount END) as Tue,
max(case when Wed = 'x' THEN amount END) as Wed,
max(case when Thu = 'x' THEN amount END) as Thu,
max(case when Fri = 'x' THEN amount END) as Fri,
max(case when Sat = 'x' THEN amount END) as Sat,
max(case when Sun = 'x' THEN amount END) as Sun
FROM tbltestquote
GROUP BY
cola, 
colb, 
colc

结果是：

我现在添加了一个名为threshold 的新列。可以看到，按cola、colb和colc分组时，threshold可以有多个值，如下图：

考虑到这一新列的我更新的 SQL 查询是这样的：

SELECT 
cola, 
colb, 
colc,
threshold,
max(case when Mon = 'x' THEN amount END) as Mon,
max(case when Tue = 'x' THEN amount END) as Tue,
max(case when Wed = 'x' THEN amount END) as Wed,
max(case when Thu = 'x' THEN amount END) as Thu,
max(case when Fri = 'x' THEN amount END) as Fri,
max(case when Sat = 'x' THEN amount END) as Sat,
max(case when Sun = 'x' THEN amount END) as Sun
FROM tbltestquote
GROUP BY
cola, 
colb, 
colc,
threshold

这会返回带有两个新行的以下结果集，这是正确的：

我现在想添加一个新的布尔列，指示在按cola、colb 和colc 分组时是否有多个阈值，根据下面的模型结果集：

请注意，cola、colb 和 colc 组具有第二个阈值的所有行的 hasMultipleThreshold 列都为 TRUE，而不仅仅是一个不同的行。

如果确实可能的话，我不确定如何修改对此列的查询。任何指导表示赞赏。

【参考方案1】：

你可以试试下面-

SELECT 
cola, 
colb, 
colc,
threshold,
max(case when Mon = 'x' THEN amount END) as Mon,
max(case when Tue = 'x' THEN amount END) as Tue,
max(case when Wed = 'x' THEN amount END) as Wed,
max(case when Thu = 'x' THEN amount END) as Thu,
max(case when Fri = 'x' THEN amount END) as Fri,
max(case when Sat = 'x' THEN amount END) as Sat,
max(case when Sun = 'x' THEN amount END) as Sun,
case when count(*) over(partition by cola,colb,colc order by cola)>1 then 1 else 0 end as hasMultipleThreshold 
FROM tbltestquote a
GROUP BY
cola, 
colb, 
colc,
threshold

【讨论】：

谢谢，但我收到以下错误Use of DISTINCT is not allowed with the OVER clause.

@JohnSteed，我已经修改了，你现在可以查看

【参考方案2】：

你可以试试这个

SELECT 
cola, 
colb, 
colc,
threshold,
max(case when Mon = 'x' THEN amount END) as Mon,
max(case when Tue = 'x' THEN amount END) as Tue,
max(case when Wed = 'x' THEN amount END) as Wed,
max(case when Thu = 'x' THEN amount END) as Thu,
max(case when Fri = 'x' THEN amount END) as Fri,
max(case when Sat = 'x' THEN amount END) as Sat,
max(case when Sun = 'x' THEN amount END) as Sun,
( select case 
        when count(threshold)>0 
            then cast(1 as bit) 
        else 
            cast(0 as bit) 
        end 
  from tbltestquote as ts where ts.cola=t.cola and ts.colb=t.colb and ts.colc= t.colc 
   group by ts.cola, ts.colb, ts.colc, ts.threshold ) as hasMultipleThreshold 
FROM tbltestquote as t
GROUP BY
cola, 
colb, 
colc,
threshold

【讨论】：

谢谢，但我收到以下错误Incorrect syntax near the keyword 'on'.