Question

sql查询获取所有发送和接收的聊天并获取最后发送的消息。目前，我有这样的办公室。但是在接收者回应之前不会返回我发送的消息。

SELECT DISTINCT
    chat.`from`,
    chat.`to`,
    chat.`message`,
    chat.`sent`,
    usuarios.`usuario`,
    usuarios.`avatar`
FROM
    chat,
    usuarios
WHERE
    (chat.`to` = 'user')
AND chat.`from` = usuarios.usuario
GROUP BY
    chat.`from`
ORDER BY
    chat.sent,
    chat.message ASC

我的数据库看起来像

| id      | int(10) unsigned
| from    | varchar(255)     
| to      | varchar(255)                  
| message | text                            
| sent    | datetime                       
| recd    | int(10) unsigned

Answer 1

我认为你错过了第二个条件

(SELECT DISTINCT
 chat.`from`,
 chat.`to`,
 chat.`message`,
 chat.`sent`,
 usuarios.`usuario`,
 usuarios.`avatar`
FROM
 chat,
 usuarios
WHERE
 chat.`to` = 'user'  AND chat.`from` = usuarios.usuario

GROUP BY
  chat.`from`
ORDER BY
 chat.sent,
 chat.message ASC)

UNION

(SELECT DISTINCT
 chat.`from`,
 chat.`to`,
 chat.`message`,
 chat.`sent`,
 usuarios.`usuario`,
 usuarios.`avatar`
FROM
 chat,
 usuarios
WHERE
 chat.`from` = 'user'  AND chat.`to` = usuarios.usuario

GROUP BY
  chat.`from`
ORDER BY
 chat.sent,
 chat.message ASC)

Answer 2

可以将您的查询更新为：

SELECT DISTINCT
    chat.`from`,
    chat.`to`,
    chat.`message`,
    chat.`sent`,
    u1.`avatar`,
    u2.`avatar`
FROM
    chat 
    inner join usuarios as u1 on chat.`from` = u1.usuario
    inner join usuarios as u2 on chat.`to` = u2.usuario
WHERE
    chat.`to` = 'user'
AND chat.`from` = 'user'
GROUP BY
    chat.`from`
ORDER BY
    chat.sent,
    chat.message ASC

所有已发送和已接收聊天的SQL查询

2 个答案: