使用select语句的MySQL语法错误

Question

Hi can you please help me in this, I don't know where my error is. here is my code:

    $capacitance =@mysql_query ("SELECT DISTINCT wwpn,  SUBSTR(val, 1, LENGTH(val) / 2) as capacitor,
                             SUBSTR(val, LENGTH(val) / 2+1) as capasitance
                             FROM   bom_csv where boardnumber ='$board' and qty<>'' and qty !='qty'");
    @mysql_query($capacitance,$connect)or die("Failed to execute query:<br />" . mysql_error(). "<br />" . mysql_errno());
    while($row = mysql_fetch_array($capacitance))
     {
         $capacitor = $row['capacitor'];
         $capacitance =$row['capasitance'];
         $adi_pn = $row['wwpn'];
     }

and the error while I am executing it by php:

Failed to execute query:
    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 'Resource id #4' at line 1
1064

Answer 1

Your first mysql_query is returning a resource (a resultset) and assigning it to $capacitance. When you execute mysql_query again in the next line, $capacitance, a resource, is turned into a string - "Resource #4", likely - which is not a proper SQL.

Also note that "Bobby Tables doesn't go to my school" is not necessarily true: escape your strings properly.

$capacitance = @mysql_query ("SELECT DISTINCT wwpn,  SUBSTR(val, 1, LENGTH(val) / 2) as capacitor,
                             SUBSTR(val, LENGTH(val) / 2+1) as capasitance
                             FROM   bom_csv where boardnumber ='" . mysql_real_escape_string($board) . "' and qty<>'' and qty !='qty'", $connect)
or die("Failed to execute query:<br />" . mysql_error(). "<br />" . mysql_errno());
while ...