MySQL JOIN only returns first match
<p>I'm trying to use this join to return multiple rows of User ID's where they are found to be in a list of recipients from a specific row in another table.</p>

<pre><code>SELECT a.`USER_ID`
FROM Users a
INNER JOIN Lists b ON a.`USER_ID` = b.`RECIP`
WHERE a.`PARENT` = '1'
AND b.`LIST_ID` = '210'
</code></pre>

<p>The query above should return 5 rows as there are 5 matches in <code>RECIP</code>, but I'm only seeing 1 result which is the first match in <code>RECIP</code></p>

<p>In the table 'Lists', row LIST_ID '210' RECIP contains '22,33,40,42,45'
As such, I hoped that the query would return 5 rows from the table 'Users' as all of those USER_ID's exist:</p>

<p>USER_ID 22</p>

<p>USER_ID 33</p>

<p>USER_ID 40</p>

<p>USER_ID 42</p>

<p>USER_ID 45</p>

<p>But I only get one result:</p>

<p>USER_ID 22</p>

<p>I've tried a number of things (SELECT DISTINCT..., GROUP BY a.ID) but I'm making no progress. To be honest I'm still trying to get my head around joins.</p>

<p>Can anyone advise?</p>