PostgreSQL行转列的多种方法


    目录
  • PostgreSQL如何行转列
    • 方法一：group by + sum + case when
    • 方法二：用postgresql的crosstab交叉函数
    • 方法三：group by + string_agg + split_part(分组，行转列，字符切割)

    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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