PostgreSQL-通过值范围获取计数 [英] postgresql - get count by value ranges
本文介绍了PostgreSQL-通过值范围获取计数的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我的数据如下:
name | value
------------
a | 3.5
a | 13.5
a | 4.9
a | 11
a | 14
b | 2.5
b | 13.6
b | 5.1
b | 12
b | 13.5
我需要按值范围分组的计数:
I need the count grouped by value ranges:
name | 0-5 | 5-10 | 10-15
-------------------------
a | 2 | 0 | 2
b | 1 | 1 | 3
感谢您的帮助。
谢谢,
grassu
Thanks, grassu
推荐答案
select name,
count(case when value <= 5 then 1 end) as "0-5",
count(case when value > 5 and value <= 10 then 1 end) as "5-10",
count(case when value > 10 and value <= 15 then 1 end) as "10-15"
from the_table
group by name;
在即将发布的9.4版本中,该代码的可读性更高:
With the upcoming version 9.4 this can be written a bit more readable:
select name,
count(*) filter (where amount <= 5) as "0-5",
count(*) filter (where value > 5 and value <= 10) as "5-10",
count(*) filter (where value > 10 and value <= 15) as "10-15"
from the_table
group by name;
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