MySQL从字段中选择一行，条件是多行

Question

Tried to find the answer, but still couldn't.. The table is as follows:

  name,    room_chat
  Ratna          2
  Ima            2
  Ratna          3
  Yanis          3

i need something like this if i select name from table where (name='Ratna' and name='Ima') i get a result

room chat
2

Thanks in advance

Answer 1

在in子句中使用如下：

select distinct a.room_chat from tableA a where a.name in ('Ratna', 'Ima')

Answer 2

You have several rows, but you want to look at a set of rows. This is called aggregation. In your case you want to look at each room chat, so you group by room_chat . You want to know whether for a room chat you find both names, so count the names.

The query:

select room_chat
from table 
where name in ('Ratna','Ima')
group by room_chat
having count(distinct name) = 2;