Php 如何获取每个用户之间最后一行对话的结果?
嗨, 请从下面的查询中找到我的表响应,我从中获得上述1对1聊天信息的响应Php 如何获取每个用户之间最后一行对话的结果?,php,mysql,Php,Mysql,嗨, 请从下面的查询中找到我的表响应,我从中获得上述1对1聊天信息的响应 mes_id subject mem_id frm_id 55 Hi 329 401 72 Re: HI yhi 689 401 83 Re: HEY HI 401 329 68 HI yhi 401 689 59 Hi
mes_id subject mem_id frm_id
55 Hi 329 401
72 Re: HI yhi 689 401
83 Re: HEY HI 401 329
68 HI yhi 401 689
59 Hi 401 1734
我只想要包含mes_id 59,72,83的响应,这是两个用户之间的最后一次对话
请帮忙
谢谢。试试这个
SELECT mes_id,SUBJECT,mem_id,frm_id
FROM messages_system_new
WHERE frm_id = '401' AND mem_id !='401'
AND trashed_user NOT LIKE '%401%'
AND TYPE = 'message'
AND FOLDER != 'saved' GROUP BY mem_id
UNION ALL
SELECT mes_id,SUBJECT,mem_id,frm_id
FROM messages_system_new
WHERE mem_id = '401' AND frm_id !='401'
AND trashed_user NOT LIKE '%401%'
AND TYPE = 'message'
AND FOLDER != 'saved' GROUP BY frm_id
感谢您的回复,但这是针对用户401的,那么我应该在哪里输出该值?您对用户401的输出值是什么意思?我的意思是,现在我使用用户id 401登录,因此我想要与我的用户进行的所有最新对话friends@user1743213但是用这个会让我失去与689的对话(
SELECT *
FROM Table1
WHERE (LEAST(mem_id, frm_id), GREATEST(mem_id, frm_id), mes_id) IN
(
SELECT LEAST(mem_id, frm_id) as x,
GREATEST(mem_id, frm_id) as y,
MAX(mes_id) as msg_time
FROM Table1
GROUP BY x, y
)
ORDER BY Mes_ID
select t.*
from
table1 t
inner join (
select max(mes_id) as mes_id
from table1
group by least(mem_id, frm_id), greatest(mem_id, frm_id)
) s on t.mes_id = s.mes_id
where mem_id = 401 or frm_id = 401
order by mes_id