如何根据条件分组和计数

Question

我是 Access 新手，我构建了一个查询以根据字段对 table 进行分组，并根据条件获取记录数。

Table:

Category       Status
Pen            Open
Pencil         Open
Pen            Closed
Pencil         Closed

我正在寻找一个查询，它给我一个如下所示的输出：

Category      Open       Closed
Pen           1          1
Pencil        1          1

到目前为止我试过了， SELECT 类别，COUNT(Status='Open')，Count(Status='Closed') FROM table GROUP BY 类别；此查询未解决问题。

TIA

Answer 1

一种方法是使用 sum 和 iif 函数进行条件聚合：

select 
  category, 
  sum(iif(status='Open',1,0)) as Open,
  sum(iif(status='Closed',1,0)) as Closed,
from table
group by category

How to group by and count based on a condition