expression engine sql query limit entries

Hi I'm not really too familiar with SQL queries using EE but I think that is what I开发者_Python百科 need here. Any advice would be appreciated. I'm basically trying to create a typical group gallery homepage that links to each members gallery - but I'm not sure how to limit it to just 1 link per author rather than all channel entries.

{exp:channel:entries channel="portfolios" author_id="not 1"}
<a href="{path=portfolios/gallery/{username}}"><img src="{avatar_url}" /></a><br>
<a href="{path=portfolios/gallery/{username}}">{author}</a><br>
{/exp:channel:entries}

This should do the trick. Be sure to replace t.channel_id = 1 with the actual channel_id of your portfolios channel.

What this will do is list all of the members who have posted entries in that channel. Note that because we're doing an SQL query, {avatar_url} isn't prepared, so we just cheat and hardcode the path to the avatars folder.

{exp:query sql="
    SELECT m.member_id, m.username, m.screen_name, m.avatar_filename
    FROM exp_members m
    LEFT JOIN exp_channel_titles t
    ON t.author_id = m.member_id
    WHERE t.channel_id = 1
    GROUP BY m.member_id
    ORDER BY m.screen_name ASC
"}
        <a href="{path=portfolios/gallery/{username}}"><img src="/images/avatars/{avatar_filename}" /></a><br>
        <a href="{path=portfolios/gallery/{username}}">{screen_name}</a><br>
{/exp:query}