我可以在postgresql中得到这个结果吗？

Question

我有

一个table1的是，有可能有表2：

想到的

Answer 1

一种解决方案涉及的子查询和row_number解析函数：

select 
    column1, 
    max(case when rn = 1 then column2 end) as column2, 
    max(case when rn = 2 then column2 end) as column3 
from (
    select *, row_number() over (partition by column1 order by column2) as rn 
    from table1 
) t 
group by column1 

或者您可以简单地使用min和max规则像下面，但我喜欢的第一个更好：

select 
    column1, 
    min(column2) as column2, 
    max(column2) as column3 
from table1 
group by column1