快上网专注成都网站设计 成都网站制作 成都网站建设
成都网站建设公司服务热线:028-86922220

网站建设知识

十年网站开发经验 + 多家企业客户 + 靠谱的建站团队

量身定制 + 运营维护+专业推广+无忧售后,网站问题一站解决

postgresql中如何实现groupbyrange

小编给大家分享一下postgresql中如何实现group by range,相信大部分人都还不怎么了解,因此分享这篇文章给大家参考一下,希望大家阅读完这篇文章后大有收获,下面让我们一起去了解一下吧!

创新互联建站是一家专业提供义马企业网站建设,专注与做网站、成都网站设计、H5响应式网站、小程序制作等业务。10年已为义马众多企业、政府机构等服务。创新互联专业的建站公司优惠进行中。

  1. 建立测试表

testdb=# CREATE TEMP TABLE team (
id serial,
name text,
birth_year integer,
salary integer
);

  1. 插入记录

testdb=# INSERT INTO team (name, birth_year, salary)
VALUES ('Gabriel', 1970, 44000),
('Tom', 1972, 36000),
('Bill', 1978, 39500),
('Bob', 1980, 29000),
('Roger', 1976, 26800),
('Lucas', 1965, 56900),
('Jerome', 1984, 33500),
('Andrew', 1992, 41600),
('John', 1991, 40000),
('Paul', 1964, 39400),
('Richard', 1986, 23000),
('Joseph', 1988, 87000),
('Jason', 1990, 55000);

  1. 查询结果

testdb=# WITH series AS (  
SELECT generate_series(1950, 2000, 10) AS time_start -- 1950 = min, 2010 = max, 10 = 10 year interval
), range AS (
SELECT time_start, (time_start + 9) AS time_end FROM series -- 9 = interval (10 years) minus 1
)
SELECT time_start, time_end,
(SELECT count(*) FROM team WHERE birth_year BETWEEN time_start AND time_end) as team_members,
round((SELECT AVG(salary) FROM team WHERE birth_year BETWEEN time_start AND time_end), 2) as salary_avg,
(SELECT MIN(salary) FROM team WHERE birth_year BETWEEN time_start AND time_end) as salary_min,
(SELECT MAX(salary) FROM team WHERE birth_year BETWEEN time_start AND time_end) as salary_max
FROM range;

输出结果:

time_start | time_end | team_members | salary_avg | salary_min | salary_max
------------+----------+--------------+------------+------------+------------
1950 |     1959 |            0 |            |            |          
1960 |     1969 |            2 |   48150.00 |      39400 |      56900
1970 |     1979 |            4 |   36575.00 |      26800 |      44000
1980 |     1989 |            4 |   43125.00 |      23000 |      87000
1990 |     1999 |            3 |   45533.33 |      40000 |      55000
2000 |     2009 |            0 |            |            |          
(6 rows)

testdb=#

以上是“postgresql中如何实现group by range”这篇文章的所有内容,感谢各位的阅读!相信大家都有了一定的了解,希望分享的内容对大家有所帮助,如果还想学习更多知识,欢迎关注创新互联行业资讯频道!


本文名称:postgresql中如何实现groupbyrange
转载来于:http://6mz.cn/article/gjjsih.html

其他资讯