Question

我需要划分销售员Yes和产品Pen 超过销售总额（在我的情况下为8）并获得总百分比。

select * from mytable   

Sale_Number      Date            Salesman_Used           Product

 1            01/01/2014             No                    Pen
 2            01/02/2014             No                    Pen
 3            01/03/2014             Yes                   Pen
 4            01/04/2014             Yes                   Pencil
 5            01/05/2014             Yes                   Pen
 6            01/06/2014             Yes                   Pencil  
 7            01/07/2014             No                    Pencil
 8            01/08/2014             No                    Pencil

我被困在缺失的部分上：

select concat(100 * count(missing this piece) / count(Sale_Number), '%') 
as "Salesman Sales for Pens"
from mytable
where Salesman_Used = 'Yes' 
and Product = 'Pen'

我尝试的问题是where clause也会影响Sale_Number ..我该怎么做？提前谢谢。

Answer 1

您可以使用子查询来获取销售条目的总数：

select concat(100 * count(*) / (select count(*) from mytable), '%') 
as "Salesman Sales for Pens"
from mytable
where Salesman_Used = 'Yes' 
and Product = 'Pen'

Answer 2

试试这个：

select concat(100 * count(missing this piece) / count(select Sale_Number from mytable), '%') 
as "Salesman Sales for Pens"
from mytable
where Salesman_Used = 'Yes' 
and Product = 'Pen'

Answer 3

聚合有filter子句：

如果指定了FILTER，那么只有filter_clause求值为true的输入行被送入聚合函数;其他行被丢弃。

所以：

select concat(100 * count(*) filter (where Salesman_Used = 'Yes' and Product = 'Pen') / count(Sale_Number), '%') 
as "Salesman Sales for Pens"
from mytable

Answer 4

我从未使用过Postgresql，但也许这样有效：

select concat(100 * (select count(*) from mytable) / count(Sale_Number), '%') 
as "Salesman Sales for Pens"
from mytable
where Salesman_Used = 'Yes' 
and Product = 'Pen'

用SQL子句划分SQL

4 个答案: