PHP Code mysteriously blank

bluethundr · November 20, 2009

Hey Guys

Thanks for your consistent and excellent help. I am really trying to master PHP connecting to MySQL. Every once in a while tho I run into a script that mysteriously refuses to be useful and I could use some help. That's why I have come to this board again, it's excellent.

That said.. I wrote a very simple script that is meant to access a template and render information from am MySQL database.

It should be noted that:

error_reporting E_ALL

display_errors = 1

is set in my php.ini file.

Here is the code. For some strange reason the page it renders is completely blank.

example.7-5.php

<?php
     require_once "HTML/Template/IT.php";
     require 'db.inc';
     
     if (!($connection = @ mysql_connect($hostname, $username, $password)))
         die("Cannot connect");
         
     if (!(mysql_select_db($databaseName, $connection)))
        showerror();
     
     if (!$regionresult = @ mysql_query ("SELECT * FROM region LIMIT 10", 
                                          $connection)))
        showerror();
        
        
     $template = NEW HTML_TEMPLATE_IT("./templates");
     $template->loadTemplatefile("example.7-4.tpl",true, true);
     
     while ($regionrow = mysql_fetch_array($regionresult));
     {
         $template->setCurrentBlock("REGION");
         $template->setVariable("REGIONNAME", $regionrow["region_name"]]);
         
          if(!($wineryresult = 
              @ mysql_query ("SELECT * FROM winery
                              WHERE region_id = {$regionrow["$region_id"]}",
                              $connection)))
                              
              showerror();
              
           while ($wineryrow = mysql_fetch_array($wineryresult))
           {
               $template->setCurrentBlock("WINERY");
               $template->setVariable("WINERYNAME", $wineryrow["winery_name"]);
               $tempalte->parseCurrentBlock();
               
           }
           $template->setCurrentBlock("REGION");
           $template->parseCurrentBlock();
     }
     $template->show();
?>

This code accesses a db include file that has all the login information:

db.inc

<?php
   // This file is the same as example 6-7, but includes mysqlclean() and shellclean() 

   $hostName = "localhost";
   $databaseName = "winestore";
   $username = "thatguy";
   $password = "shhhh";   

   function showerror()
   {
      die("Error " . mysql_errno() . " : " . mysql_error());
   }

   function mysqlclean($array, $index, $maxlength, $connection)
   {
     if (isset($array["{$index}"]))
     {
        $input = substr($array["{$index}"], 0, $maxlength);
        $input = mysql_real_escape_string($input, $connection);
        return ($input);
     }
     return NULL;
   }

   function shellclean($array, $index, $maxlength)
   {
     if (isset($array["{$index}"]))
     {
       $input = substr($array["{$index}"], 0, $maxlength);
       $input = EscapeShellArg($input);
       return ($input);
     }
     return NULL;
   }
?>

this is the simple template file living in the ./templates directory one directory down from my html docs directory

example.7-4.tpl

<!DOCTYPE HTML PUBLIC
               "-//W3C//DTD HTML 4.01 Transitional//EN"
               "http://www.w3.org/TR/html401/loose.dtd">
<html>
<head>
     <meta http-equiv="Content Type" content="text/html; charset-iso-8859-1">
     <title>Regions and Wineries</title>
<body>
<ul>
<!-- BEGIN REGION -->
<li>Region: {REGIONNAME}
<ul>
<! -- BEGIN WINERY -->
<li>{WINERYNAME}.
<! -- END WINERY -- >
</ul>
<! -- END REGION -- >
</ul>
</body>
</html>

And for some reason the page, even tho errors are turned on turn up blank. Any thoughts? :wtf:

roopurt18 · November 20, 2009

I'm not sure why you're errors aren't reporting properly, but a blank page is usually indicative of parse errors. A parse error is when you make a mistake with the PHP syntax, such as adding extra brackets or forgetting semicolons.

I was able to find the syntax errors in your source files by running PHP with the -l flag from the command line.

If you open a command prompt, you can run PHP directly from the command line.

roopurt18> php -v
PHP 5.2.11 (cli) (built: Sep 16 2009 19:39:46)
Copyright (c) 1997-2009 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2009 Zend Technologies
    with DBG v3.8.6, (C) 2000,2009, by Dmitri Dmitrienko
    with NuSphere PhpExpress v2.0.3, Copyright (c) 2002-2009 NuSphere Corp, by D
mitri Dmitrienko

If you use the -l flag, PHP will check your file for syntax errors.

roopurt18> cd \path\to\my\files
roopurt18@\path\to\my\files> php -l junk.php

Parse error: syntax error, unexpected ')' in junk.php on line 12
Errors parsing junk.php

By doing this, I found the following in your code:

// line 12 has an extra close-paren
if (!$regionresult = @ mysql_query ("SELECT * FROM region LIMIT 10", 
                                          $connection))) // <-- RIGHT HERE, REMOVE ONE OF THE )

// line 21 has an extra ]
$template->setVariable("REGIONNAME", $regionrow["region_name"]]); // <-- remove the extra ] in "region_name"]]

PFMaBiSmAd · November 20, 2009

Check what your actual error_reporting/display_errors settings are using a phpinfo(); statement in a .php file. You are likely changing a different php.ini than what php is using. You also would need an equal sign in the error_reporting = E_ALL line.

bluethundr · November 20, 2009

awesome tip trying it on the command line! this trick will come in very handy.

I checked the syntax errors, got rid of them.

but now it's reporting an SQL error and I can't seem to find it. would you mind having a look?

this is the error I get when I load the page now...

Error 1064 : 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 '' at line 2

I checked line 2 and the whole file and I can't find the SQL error. :shrug:

Thanks

roopurt18 · November 20, 2009

<?php
     require_once "HTML/Template/IT.php";
     require 'db.inc';
     
     if (!($connection = @ mysql_connect($hostname, $username, $password)))
         die("Cannot connect");
         
     if (!(mysql_select_db($databaseName, $connection)))
        showerror();
     
     if (!$regionresult = @ mysql_query ("SELECT * FROM region LIMIT 10", 
                                          $connection))
        showerror();
        
        
     $template = NEW HTML_TEMPLATE_IT("./templates");
     $template->loadTemplatefile("example.7-4.tpl",true, true);
     
     while ($regionrow = mysql_fetch_array($regionresult));
     {
         $template->setCurrentBlock("REGION");
         $template->setVariable("REGIONNAME", $regionrow["region_name"]);
         
          //
          // I'M GUESSING THIS IS WHERE YOU'RE ERROR IS AT.
          // IT'S HELPFUL TO ECHO THE SQL STATEMENT AND LOOK FOR PROBLEMS.
          //
          // I'VE ALSO REFACTORED YOUR CODE, AS IT'S READABILITY WAS POOR IMO.
          $sql = "
              SELECT * 
              FROM winery
              WHERE region_id = {$regionrow[$region_id]}
              ";
          echo $sql; // CHECK THE OUTPUT, DOES IT LOOK RIGHT?
          $wineryresult = @mysql_query ( $sql, $connection);
          if( !$wineryresult ) {
              showerror();
          }else{
              
               while ($wineryrow = mysql_fetch_array($wineryresult))
               {
                   $template->setCurrentBlock("WINERY");
                   $template->setVariable("WINERYNAME", $wineryrow["winery_name"]);
                   $tempalte->parseCurrentBlock();
                   
               }
               $template->setCurrentBlock("REGION");
               $template->parseCurrentBlock();
          }
     }
     $template->show();
?>

bluethundr · November 22, 2009

Thanks! I ran your version of the code and this is what I got…

SELECT * FROM winery WHERE region_id = Error 1064 : 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 '' at line 3

I posted a copy of the database here so you could try it yourself. It's an example database from the publisher of the book I'm reading containing no vital information.

http://rapidshare.com/files/310384292/winestore.sql.html

MD5: E16368D7CCBABCDC9FAFC9AF70BBAD57

roopurt18 · November 22, 2009

If you look at the query that was echo'ed, you can plainly see that $regionrow[$region_id] is not set.

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