Same filename and directory in other branches
  1. 4.7.x includes/database.mysqli.inc
  2. 6.x includes/database.mysqli.inc

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.

File

includes/database.mysqli.inc
View source
<?php

/**
 * @file
 * 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.
 */

/* Maintainers of this file should consult
 * http://www.php.net/manual/en/ref.mysqli.php
 */

/**
 * @ingroup database
 * @{
 */

/**
 * Report database status.
 */
function db_status_report($phase) {
  $t = get_t();
  $version = db_version();
  $form['mysql'] = array(
    'title' => $t('MySQL database'),
    'value' => $phase == 'runtime' ? l($version, 'admin/logs/status/sql') : $version,
  );
  if (version_compare($version, DRUPAL_MINIMUM_MYSQL) < 0) {
    $form['mysql']['severity'] = REQUIREMENT_ERROR;
    $form['mysql']['description'] = $t('Your MySQL Server is too old. Drupal requires at least MySQL %version.', array(
      '%version' => DRUPAL_MINIMUM_MYSQL,
    ));
  }
  return $form;
}

/**
 * Returns the version of the database server currently in use.
 *
 * @return Database server version
 */
function db_version() {
  global $active_db;
  list($version) = explode('-', mysqli_get_server_info($active_db));
  return $version;
}

/**
 * Initialise a database connection.
 *
 * Note that mysqli does not support persistent connections.
 */
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_header('HTTP/1.1 503 Service Unavailable');
    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']);

  // Test if database url has a password.
  if (isset($url['pass'])) {
    $url['pass'] = urldecode($url['pass']);
  }
  else {
    $url['pass'] = '';
  }
  $url['host'] = urldecode($url['host']);
  $url['path'] = urldecode($url['path']);
  if (!isset($url['port'])) {
    $url['port'] = NULL;
  }
  $connection = mysqli_init();
  @mysqli_real_connect($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>If you still have to install Drupal, proceed to the <a href="' . base_path() . 'install.php">installation page</a>.</p>
<p>If you have already finished installing Drupal, this either means that the username and password information in your <code>settings.php</code> file is incorrect or that we can\'t connect to the MySQL database server. This could mean your hosting provider\'s database server is down.</p>
<p>The MySQL error was: ' . theme('placeholder', mysqli_connect_error($connection)) . '.</p>
<p>Currently, the username is ' . theme('placeholder', $url['user']) . ' and the database server is ' . theme('placeholder', $url['host']) . '.</p>
<ul>
  <li>Are you sure you have the correct username and password?</li>
  <li>Are you sure that you have typed the correct hostname?</li>
  <li>Are you sure that the database server is running?</li>
  <li>Are you sure that the mysqli libraries are compiled in your PHP installation? Try using the mysql library instead by editing your <code>settings.php</code> configuration file in Drupal.</li>
</ul>
<p>For more help, see the <a href="http://drupal.org/node/258">Installation and upgrading handbook</a>. If you are unsure what these terms mean you should probably contact your hosting provider.</p>');
    exit;
  }
  else {
    if (mysqli_connect_errno() > 0) {
      drupal_maintenance_theme();
      drupal_set_header('HTTP/1.1 503 Service Unavailable');
      drupal_set_title('Unable to select database');
      print theme('maintenance_page', '<p>We were able to connect to the MySQL database server (which means your username and password are okay) but not able to select the database.</p>
<p>The MySQL error was: ' . theme('placeholder', mysqli_connect_error($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;
}

/**
 * Helper function for db_query().
 */
function _db_query($query, $debug = 0) {
  global $active_db, $queries;
  if (variable_get('dev_query', 0)) {
    list($usec, $sec) = explode(' ', microtime());
    $timer = (double) $usec + (double) $sec;
  }
  $result = mysqli_query($active_db, $query);
  if (variable_get('dev_query', 0)) {
    $bt = debug_backtrace();
    $query = $bt[2]['function'] . "\n" . $query;
    list($usec, $sec) = explode(' ', microtime());
    $stop = (double) $usec + (double) $sec;
    $diff = $stop - $timer;
    $queries[] = array(
      $query,
      $diff,
    );
  }
  if ($debug) {
    print '<p>query: ' . $query . '<br />error:' . mysqli_error($active_db) . '</p>';
  }
  if (!mysqli_errno($active_db)) {
    return $result;
  }
  else {
    trigger_error(check_plain(mysqli_error($active_db) . "\nquery: " . $query), E_USER_WARNING);
    return FALSE;
  }
}

/**
 * Fetch one result row from the previous query as an object.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   An object representing the next row of the result. The attributes of this
 *   object are the table fields selected by the query.
 */
function db_fetch_object($result) {
  if ($result) {
    return mysqli_fetch_object($result);
  }
}

/**
 * Fetch one result row from the previous query as an array.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   An associative array representing the next row of the result. The keys of
 *   this object are the names of the table fields selected by the query, and
 *   the values are the field values for this result row.
 */
function db_fetch_array($result) {
  if ($result) {
    return mysqli_fetch_array($result, MYSQLI_ASSOC);
  }
}

/**
 * Determine how many result rows were found by the preceding query.
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @return
 *   The number of result rows.
 */
function db_num_rows($result) {
  if ($result) {
    return mysqli_num_rows($result);
  }
}

/**
 * Return an individual result field from the previous query.
 *
 * Only use this function if exactly one field is being selected; otherwise,
 * use db_fetch_object() or db_fetch_array().
 *
 * @param $result
 *   A database query result resource, as returned from db_query().
 * @param $row
 *   The index of the row whose result is needed.
 * @return
 *   The resulting field or FALSE.
 */
function db_result($result, $row = 0) {
  if ($result && mysqli_num_rows($result) > $row) {
    $array = mysqli_fetch_array($result, MYSQLI_NUM);
    return $array[0];
  }
  return FALSE;
}

/**
 * Determine whether the previous query caused an error.
 */
function db_error() {
  global $active_db;
  return mysqli_errno($active_db);
}

/**
 * Return a new unique ID in the given sequence.
 *
 * For compatibility reasons, Drupal does not use auto-numbered fields in its
 * database tables. Instead, this function is used to return a new unique ID
 * of the type requested. If necessary, a new sequence with the given name
 * will be created.
 *
 * Note that the table name should be in curly brackets to preserve compatibility
 * with table prefixes. For example, db_next_id('{node}_nid');
 */
function db_next_id($name) {
  $name = db_prefix_tables($name);
  db_query('LOCK TABLES {sequences} WRITE');
  $id = db_result(db_query("SELECT id FROM {sequences} WHERE name = '%s'", $name)) + 1;
  db_query("REPLACE INTO {sequences} VALUES ('%s', %d)", $name, $id);
  db_query('UNLOCK TABLES');
  return $id;
}

/**
 * Determine the number of rows changed by the preceding query.
 */
function db_affected_rows() {
  global $active_db;

  /* mysqli connection resource */
  return mysqli_affected_rows($active_db);
}

/**
 * Runs a limited-range query in the active database.
 *
 * Use this as a substitute for db_query() when a subset of the query is to be
 * returned.
 * User-supplied arguments to the query should be passed in as separate parameters
 * so that they can be properly escaped to avoid SQL injection attacks.
 *
 * @param $query
 *   A string containing an SQL query.
 * @param ...
 *   A variable number of arguments which are substituted into the query
 *   using printf() syntax. The query arguments can be enclosed in one
 *   array instead.
 *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
 *   in '') and %%.
 *
 *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
 *   and TRUE values to decimal 1.
 *
 * @param $from
 *   The first result row to return.
 * @param $count
 *   The maximum number of result rows to return.
 * @return
 *   A database query result resource, or FALSE if the query was not executed
 *   correctly.
 */
function db_query_range($query) {
  $args = func_get_args();
  $count = array_pop($args);
  $from = array_pop($args);
  array_shift($args);
  $query = db_prefix_tables($query);
  if (isset($args[0]) and is_array($args[0])) {

    // 'All arguments in one array' syntax
    $args = $args[0];
  }
  _db_query_callback($args, TRUE);
  $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
  $query .= ' LIMIT ' . (int) $from . ', ' . (int) $count;
  return _db_query($query);
}

/**
 * Runs a SELECT query and stores its results in a temporary table.
 *
 * Use this as a substitute for db_query() when the results need to stored
 * in a temporary table. Temporary tables exist for the duration of the page
 * request.
 * User-supplied arguments to the query should be passed in as separate parameters
 * so that they can be properly escaped to avoid SQL injection attacks.
 *
 * Note that if you need to know how many results were returned, you should do
 * a SELECT COUNT(*) on the temporary table afterwards. db_num_rows() and
 * db_affected_rows() do not give consistent result across different database
 * types in this case.
 *
 * @param $query
 *   A string containing a normal SELECT SQL query.
 * @param ...
 *   A variable number of arguments which are substituted into the query
 *   using printf() syntax. The query arguments can be enclosed in one
 *   array instead.
 *   Valid %-modifiers are: %s, %d, %f, %b (binary data, do not enclose
 *   in '') and %%.
 *
 *   NOTE: using this syntax will cast NULL and FALSE values to decimal 0,
 *   and TRUE values to decimal 1.
 *
 * @param $table
 *   The name of the temporary table to select into. This name will not be
 *   prefixed as there is no risk of collision.
 * @return
 *   A database query result resource, or FALSE if the query was not executed
 *   correctly.
 */
function db_query_temporary($query) {
  $args = func_get_args();
  $tablename = array_pop($args);
  array_shift($args);
  $query = preg_replace('/^SELECT/i', 'CREATE TEMPORARY TABLE ' . $tablename . ' Engine=HEAP SELECT', db_prefix_tables($query));
  if (isset($args[0]) and is_array($args[0])) {

    // 'All arguments in one array' syntax
    $args = $args[0];
  }
  _db_query_callback($args, TRUE);
  $query = preg_replace_callback(DB_QUERY_REGEXP, '_db_query_callback', $query);
  return _db_query($query);
}

/**
 * Returns a properly formatted Binary Large Object value.
 *
 * @param $data
 *   Data to encode.
 * @return
 *  Encoded data.
 */
function db_encode_blob($data) {
  global $active_db;
  return "'" . mysqli_real_escape_string($active_db, $data) . "'";
}

/**
 * Returns text from a Binary Large OBject value.
 *
 * @param $data
 *   Data to decode.
 * @return
 *  Decoded data.
 */
function db_decode_blob($data) {
  return $data;
}

/**
 * Prepare user input for use in a database query, preventing SQL injection attacks.
 */
function db_escape_string($text) {
  global $active_db;
  return mysqli_real_escape_string($active_db, $text);
}

/**
 * Lock a table.
 */
function db_lock_table($table) {
  db_query('LOCK TABLES {' . db_escape_table($table) . '} WRITE');
}

/**
 * Unlock all locked tables.
 */
function db_unlock_tables() {
  db_query('UNLOCK TABLES');
}

/**
 * Check if a table exists.
 */
function db_table_exists($table) {
  return db_num_rows(db_query("SHOW TABLES LIKE '{" . db_escape_table($table) . "}'"));
}

/**
 * Wraps the given table.field entry with a DISTINCT(). The wrapper is added to
 * the SELECT list entry of the given query and the resulting query is returned.
 * This function only applies the wrapper if a DISTINCT doesn't already exist in
 * the query.
 *
 * @param $table Table containing the field to set as DISTINCT
 * @param $field Field to set as DISTINCT
 * @param $query Query to apply the wrapper to
 * @return SQL query with the DISTINCT wrapper surrounding the given table.field.
 */
function db_distinct_field($table, $field, $query) {
  $field_to_select = 'DISTINCT(' . $table . '.' . $field . ')';

  // (?<!text) is a negative look-behind (no need to rewrite queries that already use DISTINCT).
  return preg_replace('/(SELECT.*)(?:' . $table . '\\.|\\s)(?<!DISTINCT\\()(?<!DISTINCT\\(' . $table . '\\.)' . $field . '(.*FROM )/AUsi', '\\1 ' . $field_to_select . '\\2', $query);
}

/**
 * @} End of "ingroup database".
 */

Functions

Namesort descending Description
db_affected_rows Determine the number of rows changed by the preceding query.
db_connect Initialise a database connection.
db_decode_blob Returns text from a Binary Large OBject value.
db_distinct_field Wraps the given table.field entry with a DISTINCT(). The wrapper is added to the SELECT list entry of the given query and the resulting query is returned. This function only applies the wrapper if a DISTINCT doesn't already exist in the query.
db_encode_blob Returns a properly formatted Binary Large Object value.
db_error Determine whether the previous query caused an error.
db_escape_string Prepare user input for use in a database query, preventing SQL injection attacks.
db_fetch_array Fetch one result row from the previous query as an array.
db_fetch_object Fetch one result row from the previous query as an object.
db_lock_table Lock a table.
db_next_id Return a new unique ID in the given sequence.
db_num_rows Determine how many result rows were found by the preceding query.
db_query_range Runs a limited-range query in the active database.
db_query_temporary Runs a SELECT query and stores its results in a temporary table.
db_result Return an individual result field from the previous query.
db_status_report Report database status.
db_table_exists Check if a table exists.
db_unlock_tables Unlock all locked tables.
db_version Returns the version of the database server currently in use.
_db_query Helper function for db_query().