Warning: Mysql_Fetch_Array(): Need Help

[JawdS]

HI guys,

Everytime I run my php code I get this error message:

Warning: mysql_fetch_array(): supplied argument is not a valid MySQL result resource in /home/a3651864/public_html/footwear.php on line 96

 

This is my code:

 

$query = mysql_query("SELECT * FROM Products WHERE cat='Skate' AND subcat='Footwear' LIMIT $start, $limit_img ");
//end of query
$limit_img = 24;
$start = 0;
$cols = 3;
$cols_td = 0;
//end of table variables
$images = $row['photo'];
$product = $row['product'];
$price = $row['price'];
//end of row variables
echo "<table width='95%'><tr>";
//end of table
while ($row = mysql_fetch_array($query)){
echo "<td><div align='center'>$row[product]</div></td>";
$cols_td = $col_td + 1;
if($cols_td == $cols){
echo "</tr><tr>";
$cols_td = 0;
}
}
//end of while statement
echo "</tr></table>";

Thanks In advance!

Edited November 17, 2012 by Zane

[Zane]

That PHP error message most always means that your query is invalid.

 

You should put this at the end of your query statement so we can see the SQL error

$query = mysql_query("SELECT * FROM Products WHERE cat='Skate' AND subcat='Footwear' LIMIT $start, $limit_img ") or die(mysql_error());

[Barand]

Also echoing the query to see if it looks right can often make it obvious what is wrong.

 

echo $query;

[Andy123]

As indicated above, it's caused by mysql_query() not returning a resource. It returns FALSE on failure. mysql_fetch_array() expects a resource, but in your case, $query is not a resource. Fixing your query will obviously do the trick, but I would also validate that the query was successful just in case things break in the future.

 

$query = mysql_query("SELECT * FROM Products WHERE cat='Skate' AND subcat='Footwear' LIMIT $start, $limit_img");

if ($query) {
// Query successful

if (mysql_num_rows($query) > 0) {
// Successful and at least one row returned
}

else {
// Successful but no rows returned
}
}

 

In this way, you can present user friendly error messages along with logging for debugging purposes.

[swisse]

Hi JawdS,

$row[product] lacks single quotation marks, thus it should read $row['product'].

[Pikachu2000]

Technically, when an associative array element is in a quoted string, the index doesn't need to be quoted. If the index is quoted, complex notation needs to be used, e.g.,

$str = "quoted string with {$array['index']} in it";

Edited November 17, 2012 by Pikachu2000

[Barand]

I'd look at the order in which these statements occur

 

$query = mysql_query("SELECT * FROM Products WHERE cat='Skate' AND subcat='Footwear' LIMIT $start, $limit_img ");
//end of query
$limit_img = 24;
$start = 0;