SQL Server union all不会显示所有需要的结果

Question

我需要显示此查询的所有结果（更改+ servicerequest + servizio）

select data, cast((((ore*60.0)+minuti)/60) as decimal(10,2)) as change
              from mainGrid
              where username = 'marco_polo' and
              YEAR(data) = 2020 and
              MONTH(data) = 5 and
              eventType = 'Change' 
              union all
select data, cast((((ore*60.0)+minuti)/60) as decimal(10,2)) as servicerequest
              from mainGrid
              where username = 'marco_polo' and
              YEAR(data) = 2020 and
              MONTH(data) = 5 and
              eventType = 'Service request'
              union all
select data, cast((((ore*60.0)+minuti)/60) as decimal(10,2)) as servizio
              from mainGrid
              where username = 'marco_polo' and
              YEAR(data) = 2020 and
              MONTH(data) = 5 and
              eventType = 'Servizio'
order by data

正在运行的查询中，我仅获得“更改”值：

   data       change
---------------------
2020-05-30     9.15
2020-05-12     8.13

有什么建议吗？

Answer 1

那是因为其他类型被过滤掉了-您可能名称错误。

在任何情况下，您都可以使用in来写得更简单：

select m.event_type, m.data,
       cast((((m.ore*60.0)+m.minuti)/60) as decimal(10,2)) as change
from mainGrid m
where username = 'marco_polo' and and
      data >= '2020-05-01' and
      data < '2020-06-01' and
      eventType in ('Change' , ''Service request', 'Servizio');

这不会解决问题。

Answer 2

如果要在单独的列中输入3种类型，则可以编写：

 select data, 
  case when eventType = 'Change'  then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else 0 end as change,
  case when eventType = 'Service request' then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else 0 end as servicerequest, 
  case when eventType = 'Servizio' then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else  0 end as servizio
from mainGrid
where username = 'marco_polo' and
   YEAR(data) = 2020 and
   MONTH(data) = 5 and
   (eventType = 'Change' or eventType = 'Service request' or eventType = 
    'Servizio')
order by data

如果要在一列中输入3种类型，则可以编写：

 select data, cast((((ore*60.0)+minuti)/60) as decimal(10,2)) as calcColumn
from mainGrid
where username = 'marco_polo' and
   YEAR(data) = 2020 and
   MONTH(data) = 5 and
   (eventType = 'Change' or eventType = 'Service request' or eventType = 
    'Servizio')
order by data

Answer 3

现在我明白了：

   data          change            servicerequest    servizio
2020-05-30        0.00                  0.00          9.15
2020-05-12        0.00                  0.00          8.13
2020-05-30        0.00                 10.02          0.00

但是我想按“数据”分组：在这种情况下，只有一行数据= 2020-05-30。问题是，如果我仅添加“分组数据”，则会收到一条错误消息，告诉我未使用other列。因此，我添加了其他类似的列：

select data, 
  case when eventType = 'Change' then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else 0 end as change,
  case when eventType = 'Service request' then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else 0 end as servicerequest, 
  case when eventType = 'Servizio' then cast((((ore*60.0)+minuti)/60) as decimal(10,2)) else  0 end as servizio
from mainGrid
where username = 'marco_polo' and
   YEAR(data) = 2020 and
   MONTH(data) = 5 and
   (eventType = 'Change' or eventType = 'Service request' or eventType = 'Servizio')
group by data, eventType, ore, minuti
order by data

但是我得到的结果相同，没有分组。有什么建议么？谢谢。