Trying to get PHP to connect to a MySQL Database

bassplayer69 · 03-13-2008, 06:54 AM

I installed apache, php and mysql on my Mandriva 2008.0 machine and I was able to setup a database, tables and add rows to the tables. Now, I want to be able to access this database through php. I have this code:

Code:

$db = new mysqli('localhost', 'username', 'password', 'database');

if (mysqli_connect_errno())
{
  echo 'Can't connect to the database.';
  exit();
}

I always get an error connecting. I can use the same username, password and database from the command line (mysql -u username ...) and connect no problem. Is there any type of configuration I need to setup to get this to work? Am I missing something?

key4ce · 03-13-2008, 09:19 AM

what is your php and mysql version?

Guttorm · 03-13-2008, 09:39 AM

Hi

If you change the echo to this:

PHP Code:



printf("Can't connect to localhost. Error: %s\n", mysqli_connect_error());

You will then get a proper error message so it will be easier to figure out what the problem is.

derzok · 03-13-2008, 10:36 AM

Just in case: You are filling in "password" and "username" with your actual mysql password and mysql username, right?

bassplayer69 · 03-13-2008, 11:55 AM

Quote:

Originally Posted by derzok

Just in case: You are filling in "password" and "username" with your actual mysql password and mysql username, right?

Yes, of course.

bassplayer69 · 03-13-2008, 11:58 AM

Quote:

Originally Posted by key4ce

what is your php and mysql version?

PHP: 5.2.5

MYSQL: 5.0.45

key4ce · 03-13-2008, 12:24 PM

Do you have the php_mysqli plugin? If not try the native driver found here

bassplayer69 · 03-13-2008, 03:06 PM

Quote:

Originally Posted by key4ce

Do you have the php_mysqli plugin? If not try the native driver found here

Your link requires me to register first before downloading the native php driver. Here is the error message from error_log in the /var/log/httpd directory:

Code:

[Thu Mar 13 16:01:08 2008] [error] [client 127.0.0.1] PHP Fatal error:  Class 'mysqli' not found in /php/results.php on line 31

That's probably the issue. Where can I find the php configuration files in order to add this?

key4ce · 03-13-2008, 04:12 PM

You fix that by the link i gave you.
follow the steps (as well as the configuration as the download) and you will resolve that error

key4ce · 03-13-2008, 04:15 PM

Sorry I made a mistake there.

try this as a connection script:
mysql_connect("localhost","username","password"); //(host, username, password)

//specify database ** EDIT REQUIRED HERE **
mysql_select_db("database") or die("Unable to select database");

your mysqli script isn't the standard way for connecting.

as i think php might look for defining mysqli as a variable rather then a actual use like mysql_connect

(sorry getting a bit late. so please excuse me if i am being vague)

AdaHacker · 03-13-2008, 06:35 PM

Your connection script is fine - seeing how it's straight of the PHP manual, it'd better be! The problem is that the PHP mysqli extension is either not enabled or (more likely) not installed. I'm assuming you installed PHP through your distribution's package manager. If so, there should also be a package for the mysqli extension (in Ubuntu, it's named php5-mysqli). Just install that and you should be all set. There's no need to mess around with building mysqlnd - the package provided by your distro should be more than sufficient.

key4ce · 03-13-2008, 06:51 PM

haha.. well it's more recommended to use that script.
and with it.. his problem doesn't seem to be a MYSQL or PHP Extension error (check the link i first posted)
as i posted the extension link for mysqli at first.

if you see the error it is more likely a error of php (seeing it as a VAR) then extension error
and the script i posted was confirmed by our key4ce developer..

try it.. (never hurts to try right?)

AdaHacker · 03-13-2008, 07:50 PM

No, it's definitely a missing extension. The mysqli class is built into the extension. The only reason it could not be found is because the extension has not been loaded.

As for the connection script, while the one you posted will definitely work, it's the old way of doing things. Unless you're stuck with an old version of PHP and/or MySQL, or a large existing codebase that uses the mysql extension, you should be using mysqli. The support for prepared statements alone should be enough reason. The original mysql extension was never that great and there's no reason to use it now that better extensions like mysqli and pdo are around.

bassplayer69 · 03-13-2008, 08:56 PM

Quote:

Originally Posted by AdaHacker

No, it's definitely a missing extension. The mysqli class is built into the extension. The only reason it could not be found is because the extension has not been loaded.

As for the connection script, while the one you posted will definitely work, it's the old way of doing things. Unless you're stuck with an old version of PHP and/or MySQL, or a large existing codebase that uses the mysql extension, you should be using mysqli. The support for prepared statements alone should be enough reason. The original mysql extension was never that great and there's no reason to use it now that better extensions like mysqli and pdo are around.

Thank you for your response. I did find and installed the php-mysqli-5.2.4-2mdv2008.0 package. I also pointed my browser to the .php page and again, I'm still getting that error. Saying that the class mysqli is not found. Do I have include a file in my php script to use this library???

bassplayer69 · 03-13-2008, 09:00 PM

Here's the actual code for the whole page:

Code:

<html>
  <head>
    <title>Book-O-Rama Search Results</title>
  </head>
  <body>
    <h1>Book-O-Rama Search Results</h1>
    <?php
      // create short variable names
      $searchtype = $_POST['searchtype'];
      $searchterm = $_POST['searchterm'];
      
      $searchtype = 'Title';
      $searchterm = 'Java';
      
      $searchterm = trim($searchterm);
      
      if (!$searchtype || !$searchterm)
      {
      	echo 'You have not enetered search details.  Please go back and try again.';
      	exit();
      }
      
      if (!get_magic_quotes_gpc())
      {
      	$searchtype = addslashes($searchtype);
      	$searchterm = addslashes($searchterm);
      }
      
      @ $db = new mysqli('localhost', 'username', 'password', 'books');
      
      if (!$db)
      {
        printf("<p>Can't connect to localhost. Errorcode: %d</p><br/>", mysqli_connect_errno());
        exit();
      }
            
      $query = "select * from books where ".$searchtype." like '%".$searchterm."%'";
      $result = $db->query($query);
      
      $num_results = $result->num_rows;
      
      echo '<p>Number of books found: '.$num_results.'</p>';
      
      $result->free();
      $db->close();
    ?>
      
  </body>
</html>

Its very basic. I'm just learning php. I've been using ASP and ASP.NET for the past seven years, so the concepts aren't new, just the syntax and what libraries I need. This page is the POST page, but I assigned the variables just so I can call this page to see if it works.