group后无法查另一个字段

Question

比如说这张表，我要对send字段group，然后取出每个send的五条text，该怎么写sql?

Answer 1

select t.send,t.text from (
select
a.send,a.text,row_number()over(partition by a.send order by a.text ) r
from test_send a) t
where t.r<=5

Answer 2

Answer 3

select send,count(send) from tableName group by send having count(send)=5