PostgreSQL行转列的多种方法
作者：围城客
这篇文章主要介绍了PostgreSQL行转列的多种方法,本文给大家分享三种方法,每种方法结合示例代码给大家介绍的非常详细,需要的朋友可以参考下
PostgreSQL如何行转列
方法一：group by + sum + case when
select name, sum(case when zbfm='年龄' then value else 0 end) as 年龄, sum(case when zbfm='身高' then value else 0 end) as 身高, sum(case when zbfm='体重' then value else 0 end) as 体重 from test group by name having name like '%1' and length(name)=4 order by 年龄 desc
方法二：用postgresql的crosstab交叉函数
crosstab(unknown, unknown) does not exist
select * from
crosstab(
'select name,zbfm,value from test where name like ''%1'' and length(name)=4',$$values('年龄'), ('身高'), ('体重')$$)
as score(name text, 年龄 int, 身高 int, 体重 int)
order by 年龄 desc
方法三：group by + string_agg + split_part(分组，行转列，字符切割)
select name, split_part(split_part(temp,',',1),':',2) as 年龄, split_part(split_part(temp,',',2),':',2) as 身高, split_part(split_part(temp,',',3),':',2) as 体重 from( select name, string_agg(zbfm||':'||value,',') as temp from test group by name having name like '%1' and length(name)=4 ) as t order by 年龄 desc
group by + string_agg
select name, string_agg(zbfm||':'||value,',') from test group by name having name like '%1' and length(name)=4
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