小编典典

我怎样才能在同一个查询中减去两个计数选定的列?

sql

我有一个 SQL 查询,它计算表中的项目数并按省名对它们进行分组。我有另一个要加入的表,其中有一列用于上传,仅显示已上传的项目。我想从减去两列中得到待处理的项目。

这是我的数据

totallabs   LabUploaded
147           0
150           0
156           0
273           0
176           0
244           1
38            1
131           0
197           1
133           1
124           0

这就是我们要达到的目标

totallabs   LabUploaded  Pending
147           0           147
150           0           150
156           0           156
273           0           273
176           0           176
244           1           243
38            1           37
131           0           131
197           1           196
133           1           132
124           0           124

这是我对第一个表的查询

select count(l.facility_name) as totallabs,
count(u.lab_code) as LabUploaded
from labs l 
left join upload u on  u.lab_code = l.mfl_code
inner join province p on p.id = l.province_code
group by p.province_name

我试图用SubQueryAlias给我数据但没有得到正确的数据,

select  SubQueryAlias.*
,       totallabs - LabUploaded as pending
from    (
        select  (
                select count(l.facility_name) 
                from   labs l
                ) as totallabs,            
                (
                select  count(u.lab_code) 
                from    upload u
                ) as LabUploaded 
        from    labs l
        left join upload u on  u.lab_code = l.mfl_code 
inner join districts p on p.id = l.district_code
group by p.district_name
        ) as SubQueryAlias

如何在两个计数列之间减去并获取待处理的数据。任何帮助表示赞赏


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2022-07-21

共1个答案

小编典典

下次,请提供一些示例数据和表格,您可以使用 SQL Fiddle 使其更容易。

检查这是否适合您的需求:

SELECT province_code,
COUNT(labs.mfl_code) TotalLabs,
COUNT(uploads.lab_code) Uploads,
COUNT(labs.mfl_code) - COUNT(uploads.lab_code) Pending
FROM labs
LEFT join uploads ON uploads.lab_code = labs.mfl_code
GROUP BY province_code
SQl 小提琴示例: http ://sqlfiddle.com/#!9/c689e7/1

如果您发现我的回答有用,如果您投票并标记为已接受,我将不胜感激。

2022-07-21