Same name in this branch
  1. 4.7.x includes/database.pgsql.inc \db_connect()
  2. 4.7.x includes/database.mysqli.inc \db_connect()
  3. 4.7.x includes/database.mysql.inc \db_connect()
Same name and namespace in other branches
  1. 4.6.x includes/database.pgsql.inc \db_connect()
  2. 4.6.x includes/database.mysql.inc \db_connect()
  3. 5.x includes/database.pgsql.inc \db_connect()
  4. 5.x includes/database.mysqli.inc \db_connect()
  5. 5.x includes/database.mysql.inc \db_connect()
  6. 6.x includes/database.pgsql.inc \db_connect()
  7. 6.x includes/database.mysqli.inc \db_connect()
  8. 6.x includes/database.mysql.inc \db_connect()

Initialise a database connection.

Note that mysqli does not support persistent connections.

Related topics

1 call to db_connect()
db_set_active in includes/database.inc
Activate a database for future queries.

File

includes/database.mysqli.inc, line 22
Database interface code for MySQL database servers using the mysqli client libraries. mysqli is included in PHP 5 by default and allows developers to use the advanced features of MySQL 4.1.x, 5.0.x and beyond.

Code

function db_connect($url) {

  // Check if MySQLi support is present in PHP
  if (!function_exists('mysqli_init') && !extension_loaded('mysqli')) {
    drupal_maintenance_theme();
    drupal_set_title('PHP MySQLi support not enabled');
    print theme('maintenance_page', '<p>We were unable to use the MySQLi database because the MySQLi extension for PHP is not installed. Check your <code>PHP.ini</code> to see how you can enable it.</p>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }
  $url = parse_url($url);

  // Decode url-encoded information in the db connection string
  $url['user'] = urldecode($url['user']);
  $url['pass'] = urldecode($url['pass']);
  $url['host'] = urldecode($url['host']);
  $url['path'] = urldecode($url['path']);
  $connection = mysqli_init();
  @mysqli_real_connect($connection, $url['host'], $url['user'], $url['pass'], substr($url['path'], 1), $url['port'], NULL, MYSQLI_CLIENT_FOUND_ROWS);

  // Find all database connection errors and error 1045 for access denied for user account
  if (mysqli_connect_errno() >= 2000 || mysqli_connect_errno() == 1045) {
    drupal_maintenance_theme();
    drupal_set_header('HTTP/1.1 503 Service Unavailable');
    drupal_set_title('Unable to connect to database server');
    print theme('maintenance_page', '<p>This either means that the username and password information in your <code>settings.php</code> file is incorrect or we can\'t contact the MySQL database server through the mysqli libraries. This could also mean your hosting provider\'s database server is down.</p>
<p>The MySQL error was: ' . theme('placeholder', mysqli_error($connection)) . '.</p>
<p>Currently, the username is ' . theme('placeholder', $url['user']) . ' and the database server is ' . theme('placeholder', $url['host']) . '.</p>
<ul>
  <li>Are you sure you have the correct username and password?</li>
  <li>Are you sure that you have typed the correct hostname?</li>
  <li>Are you sure that the database server is running?</li>
  <li>Are you sure that the mysqli libraries are compiled in your PHP installation? Try using the mysql library instead by editing your <code>settings.php</code> configuration file in Drupal.</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }
  else {
    if (mysqli_connect_errno() > 0) {
      drupal_maintenance_theme();
      drupal_set_title('Unable to select database');
      print theme('maintenance_page', '<p>We were able to connect to the MySQL database server (which means your username and password are okay) but not able to select the database.</p>
<p>The MySQL error was: ' . theme('placeholder', mysqli_error($connection)) . '.</p>
<p>Currently, the database is ' . theme('placeholder', substr($url['path'], 1)) . '. The username is ' . theme('placeholder', $url['user']) . ' and the database server is ' . theme('placeholder', $url['host']) . '.</p>
<ul>
  <li>Are you sure you have the correct database name?</li>
  <li>Are you sure the database exists?</li>
  <li>Are you sure the username has permission to access the database?</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
      exit;
    }
  }

  /* Force UTF-8 */
  mysqli_query($connection, 'SET NAMES "utf8"');
  return $connection;
}