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POPHP/MySQL Join statement not working
 

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  1. POPHP/MySQL Join statement not working
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    <p>I am trying create an average rating for a store listing using Mysql <code>AVG</code> and then displaying the average next to each store on a directory list page. </p> <p>Every time someone leaves a review for a store, they give a rating of 1-5, which is inserted into <code>TABLE reviews</code> in column <code>rating</code></p> <p>The store data is coming from <code>TABLE reviews</code> and the table relationship is coming from a column in both tables named <code>store_id</code>. I trying to use a join statement to get the average to display next to each store.</p> <p>This is the current code in the loop for the rating with join statement:</p> <pre><code>&lt;?php echo "&lt;table&gt;\n"; echo "&lt;tr&gt;&lt;th&gt;Store ID&lt;/th&gt;&lt;th&gt;Rating&lt;/th&gt;&lt;/tr&gt;\n"; $result1 = mysql_query("SELECT s.store_id AVG(r.rating) AS avg_rating FROM stores as s JOIN reviews as r ON s.store_id = r.store_name GROUP BY s.store_id"); while ($row1 = mysql_fetch_assoc($result1)) { echo "&lt;tr&gt;&lt;td&gt;$row1[store_id]&lt;/td&gt;&lt;td&gt;$row1[avg_rating]&lt;/td&gt;&lt;/tr&gt;\n"; } echo "&lt;/table&gt;\n";?&gt; echo "&lt;/table&gt;\n";?&gt; </code></pre> <p>This is the SQL error I am getting</p> <pre><code>You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '(r.rating) AS avg_rating FROM stores' </code></pre> <p>This is the PHP error I am getting:</p> <blockquote> <p>Warning: mysql_fetch_assoc() expects parameter 1 to be resource, boolean given in /home/shopping/public_html/retailers.php on line 227</p> </blockquote> <p>Line 227 is this line from the code above:</p> <pre><code>while ($row1 = mysql_fetch_assoc($result1)) { </code></pre> <p>These are my tables 2 structures:</p> <pre><code>CREATE TABLE `stores` ( `store_id` int(11) unsigned NOT NULL AUTO_INCREMENT, `store_name` varchar(255) NOT NULL DEFAULT '', CREATE TABLE `reviews` ( `rating_id` int(11) unsigned NOT NULL AUTO_INCREMENT, `store_id` int(11) NOT NULL DEFAULT '0', `rating` tinyint(1) NOT NULL DEFAULT '0', </code></pre>
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    1. This table or related slice is empty.
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    1. USMichael Falciglia
    1. USMichael Falciglia
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    1. This table or related slice is empty.
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    1. PO
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      1. VTUpMod
    2. VO
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    3. VO
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      1. VTUpMod
    1. CO*sidenote:* stop using deprecated `mysql_*` functions. use [MySQLi](http://php.net/manual/en/book.mysqli.php) or [PDO](http://php.net/manual/en/book.pdo.php) instead.
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      1. USRaptor
    2. CODo you have an r.store_name? Perhaps you mean r.retailer_id?
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      1. UStabstop
    3. COPlease, do not use the truly awful `mysql_query` interface. The problem here is you're getting `false` back instead of a resource, your query didn't work, so you can't fetch it. PDO can emit exceptions which are a lot harder to miss. Stop using `mysql_query` before you create even more legacy code you'll have to re-write.
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      1. UStadman
 

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