I'm having a problem with a many-to-one relationships in a MySQL DB that I am trying to query.

I am working with three tables in a CMS (written by someone else and not easily modified). The first table lists articles, the second table lists authors and the third table maps authors to articles such that each article can have an unlimited number of authors.

When I need to select articles I can do so like this:

This way I select one row for each article and author and get a table like this (extraneous fields removed for clarity):

Since IDs are unique it is a simple operation to use PHP to convert these results into four different articles with one of the articles having three different authors.

Where I run into problems is on pages where I need to impose a limit on the number of articles I select. I don't know of an easy / efficient way to select the three most recent articles and all their authors.

If I impose a LIMIT on the number of rows that I select the resulting table will either truncate some of the articles or authors that I want to select.

Can someone help me find an efficient way to limit my selection to include as many rows as necessary but only three unique article ids?

You can always use subqueries to limit your selection:

SELECT *
FROM (SELECT id
FROM articles
ORDER BY id DESC
LIMIT 5) a,
article_authors aa,
authors au,
articles art
WHERE art.id = a.id
AND aa.article_id = art.id
AND au.id = aa.author_id;