如何在 sql server 2016 中组合查询

Question

我在 SQL Server 2016 中有两个生成汇总数据的查询 并希望将它们组合成一个查询 结果。第一个引入特定选举周期的数据， 第二个返回当前月份的数据。我想得到一个 包含选举周期和当前的单个结果集 月份。

    I've tried Union to put the two queries together however there could 
    be duplicate members and I would like to count each member one time.

我已经尝试过 union 语句，但是因为我希望将结果放在单独的列中，所以这种方法不起作用。

    Query 1
select d.note  
      ,isnull(count(distinct d.member_id),0) as '2019 EOY'  
from diary_tab d (nolock)  
left join member_tab m (nolock)  
     on m.member_id = d.member_id  
where year(m.effective_dt) = '2019'  
  and m.election_period = 'EOY'  
group by d.note  

    Query 2  
select d.note  
      ,isnull(count(distinct d.member_id),0) as 'Current MTD'  
from diary_tab d (nolock)  
group by d.note  



    currently I get these results:  
    note      EOY  
    -----     ----  
    Note1       20  
    Note2        5  

    Note      MTD  
    -----     -----  
    Note1       6  
    Note2       2  

    I would like to get this:  

    Note      EOY      MTD  
    -----     ----     -----  
    Note1       20       6  
    Note2        5       2

Answer 1

您可以使用条件聚合：

select d.note  
  ,[2019 EOY] = isnull(count(distinct CASE WHEN year(m.effective_dt) = 2019 AND m.election_period = 'EOY' THEN d.member_id END),0)
  ,[Current MTD] = isnull(count(distinct d.member_id),0)
from diary_tab d
left join member_tab m 
  on m.member_id = d.member_id  
group by d.note;

(NOLOCK) 不是涡轮增压按钮，可能会导致错误结果。