oracle、postgresql、mysql行转列的内置函数

1、需求描述

查询人员的年龄

select t.age,t.name from table_name t where t.age = 20;

age	name
16	Jack
16	Jones
16	Mark
16	Lucy
16	Adams

要达到的效果：

age	names
16	Jack,Jones,Mark,Lucy,Adams

2、解决方案

1）oracle：listagg() within group()

select t.age, listagg(t.name, ',') within group (order by t.name) names
from table_name t
where t.age = 20 group by t.age

2） postgresql：string_agg()

select t.age, string_agg(t.name, ',') as names
from table_name t
where t.age = 20 group by t.age

3） mysql：group_concat()

select t.age, group_concat(t.name order by t.name separator ',') as names
from table_name t
where t.age = 20 group by t.age