參考了一下這篇文章：https://blog.csdn.net/xichenguan/article/details/51764100 ， 感謝原作者

有兩個表，分別存放了【操作員】和【單據】，要根據單據的不同類型來分類匯總(銷售單、銷售退貨單，筆數和金額)，並且顯示在同一張表裏，不想用做兩次查詢再合並的方法，研究了一下，終於搞定：

d_employee表

d_bilndx表

代碼如下：

select  b.inputid as 開單員編號, 
        e.fullname as 開單員, 

        isnull( ( select count(*)
          from d_bilndx
          
 
where draft=3 and biltype=12 and d_bilndx.inputid=e.id
        ), 0) as ‘銷售開單筆數‘,

        isnull( ( select sum(d_bilndx.amount)
          from d_bilndx
          where draft=3 and biltype=12 and d_bilndx.inputid=e.id
        ), 0) as ‘銷售開單金額‘,

        isnull( ( select count(*)
          from d_bilndx
          
 
where draft=3 and biltype=13 and d_bilndx.inputid=e.id
        ), 0) as ‘銷售退單筆數‘,

        isnull( ( select sum(d_bilndx.amount)
          from d_bilndx
          where draft=3 and biltype=13 and d_bilndx.inputid=e.id
        ), 0) as ‘銷售退單金額‘,

        count(b.biltype) as 開單總筆數,
        sum(b.Amount) as
 
 開單金額

from d_bilndx as b
left join d_employee as e 
on b.inputid=e.id 
where b.draft=3 and ( b.biltype=12 or b.biltype=13 )
group by b.inputid, e.fullname, e.id

得到完美結果：

SQL一次性查詢一個字段不同條件下的統計結果