查询显示冗余ID

Question

I' am making a messaging system like Facebook has. I' am stuck where I have to Query the database and get the conversation between User 1 and User 2.

MySQL Query

SELECT 
    messages.message_id, 
    messages.message_from, 
    messages.message_to
FROM 
    messages
INNER JOIN
    profiles
WHERE 
    messages.message_to = '1' AND messages.message_from = '2' OR
    messages.message_to = '2' AND messages.message_from = '1'
ORDER BY 
    messages.message_id 
DESC

Database Structure and Query Result

Database Scheme

As you can see, message_id has redundant ID's. There is something am not doing right in my Query, What am I missing?

Answer 1

Try

SELECT DISTINCT messages.message_id