Question

我有一个类似

的mysql表聊天

+---------+-----------+-------------+----------------+
| chat_id | sender_id | receiver_id | msg            |
+---------+-----------+-------------+----------------+
|       1 |      1002 |        1001 | test           |
|       2 |      1001 |        1002 | test           |
|       3 |      1002 |        1001 | test           |
|       5 |      1001 |        1002 | asdf           |
|       6 |      1003 |        1001 | tesdf          |
|       9 |      1001 |        1003 | tasdfa a fasd  |
|      10 |      1001 |        1004 | dsf asdf a     |
|      11 |      1005 |        1001 | dsf asdf asdf  |
+---------+-----------+-------------+----------------+

用户1002,1003,1004,1005中存在用户1001的会话

我需要用户1001进行对话的用户列表（1002,1003,1004,1005）。

mysql查询是什么？请帮帮我。

Answer 1

您可以在sender或receiver中选择要搜索的特定用户的所有记录。在该测试之后，如果发送者的id等于您要搜索的用户ID，如果它是相等的，则返回接收者的id，否则返回发送者。提供DISTINCT关键字仅显示结果列表中的唯一ID。

SELECT  DISTINCT 
        CASE WHEN sender_id = 1001 
            THEN receiver_id 
            ELSE sender_id 
        END userID
FROM    tableName
WHERE   1001 IN (sender_id, receiver_id)

SQLFiddle Demo

因为你想连接行based on your comment

SELECT  GROUP_CONCAT(DISTINCT
                    CASE WHEN sender_id = 1001 
                        THEN receiver_id 
                        ELSE sender_id 
                    END) userID
FROM    tableName
WHERE   1001 IN (sender_id, receiver_id)

SQLFiddle Demo

Answer 2

试试这个

select  DISTINCT if(receiver_id='1001',sender_id,receiver_id) AS id
from    YourTable
where   (sender_id = 1001 OR receiver_id = 1001)

编辑：

SELECT GROUP_CONCAT( DISTINCT (
if( receiver_id = '1001', sender_id, receiver_id ) )
) AS concat
FROM chat
WHERE (
sender_id =1001
OR receiver_id =1001
)

我认为您了解GROUP_CONCAT尺寸问题。您可以参考此http://dev.mysql.com/doc/refman/5.0/en/group-by-functions.html#function_group-concat

Answer 3

您可以使用union合并发件人或收件人为1001的两个查询：

select  distinct sender_id
from    YourTable
where   receiver_id = 1001
union
select  distinct receiver_id
from    YourTable
where   sender_id = 1001

Answer 4

HI请检查以下查询

从表中选择不同的receiver_id，其中distinct sender_id = 1001

Answer 5

(select distinct receiver_id from table where sender_id = 1001)
union distinct
(select distinct sender_id from table where receiver_id = 1001);

MySQL查询从对话列表中获取用户列表

5 个答案: