mysql left join and order by

Question

hi i have to different tables m_mp and m_answer both have m_date and m_mdate which fills with time() function i want to select both entries but order by date

example:

first table: 'some text','6464647776' second table 'some answer','545454545'

so i want to show first second table and then the first one

this is the code im using:

SELECT r.*,u.* 
FROM `mensajes` as r 
LEFT JOIN `m_answer` as u on r.id = u.id_m 
WHERE r.id  = '1' 
ORDER BY m_date

and then display the result of each table using while-loop

Answer 1

I guess I get what you want to do.

You may force both grouping and ordering using ORDER BY, like this:

http://sqlfiddle.com/#!9/373d65/9

I know the solution is not optimal in terms of speed, but, given proper indices, I suspect performance to be acceptable, unless you are already aiming for millions of messages; when that time comes, you would like to either properly GROUPBY, or make subsequent queries for just the recently answered questions from the current page.