C:/drupal/includes/database.inc

Go to the documentation of this file.

<?php
// $Id: database.inc,v 1.94 2008/04/20 18:23:21 dries Exp $

define('DB_ERROR', 'a515ac9c2796ca0e23adbe92c68fc9fc');

function update_sql($sql) {
  $result = db_query($sql, true);
  return array('success' => $result !== FALSE, 'query' => check_plain($sql));
}

function db_prefix_tables($sql) {
  global $db_prefix;

  if (is_array($db_prefix)) {
    if (array_key_exists('default', $db_prefix)) {
      $tmp = $db_prefix;
      unset($tmp['default']);
      foreach ($tmp as $key => $val) {
        $sql = strtr($sql, array('{' . $key . '}' => $val . $key));
      }
      return strtr($sql, array('{' => $db_prefix['default'], '}' => ''));
    }
    else {
      foreach ($db_prefix as $key => $val) {
        $sql = strtr($sql, array('{' . $key . '}' => $val . $key));
      }
      return strtr($sql, array('{' => '', '}' => ''));
    }
  }
  else {
    return strtr($sql, array('{' => $db_prefix, '}' => ''));
  }
}

function db_set_active($name = 'default') {
  global $db_url, $db_type, $active_db, $db_prefix;
  static $db_conns, $active_name = FALSE;

  if (empty($db_url)) {
    include_once 'includes/install.inc';
    install_goto('install.php');
  }

  if (!isset($db_conns[$name])) {
    // Initiate a new connection, using the named DB URL specified.
    if (is_array($db_url)) {
      $connect_url = array_key_exists($name, $db_url) ? $db_url[$name] : $db_url['default'];
    }
    else {
      $connect_url = $db_url;
    }

    $db_type = substr($connect_url, 0, strpos($connect_url, '://'));
    $handler = "./includes/database.$db_type.inc";

    if (is_file($handler)) {
      include_once $handler;
    }
    else {
      _db_error_page("The database type '" . $db_type . "' is unsupported. Please use either 'mysql' or 'mysqli' for MySQL, or 'pgsql' for PostgreSQL databases.");
    }

    $db_conns[$name] = db_connect($connect_url);
    // We need to pass around the simpletest database prefix in the request
    // and we put that in the user_agent header.
    if (preg_match("/^simpletest\d+$/", $_SERVER['HTTP_USER_AGENT'])) {
      $db_prefix = $_SERVER['HTTP_USER_AGENT'];
    }

  }

  $previous_name = $active_name;
  // Set the active connection.
  $active_name = $name;
  $active_db = $db_conns[$name];

  return $previous_name;
}

function _db_error_page($error = '') {
  global $db_type;
  drupal_maintenance_theme();
  drupal_set_header('HTTP/1.1 503 Service Unavailable');
  drupal_set_title('Site off-line');

  $message = '<p>The site is currently not available due to technical problems. Please try again later. Thank you for your understanding.</p>';
  $message .= '<hr /><p><small>If you are the maintainer of this site, please check your database settings in the <code>settings.php</code> file and ensure that your hosting provider\'s database server is running. For more help, see the <a href="http://drupal.org/node/258">handbook</a>, or contact your hosting provider.</small></p>';

  if ($error && ini_get('display_errors')) {
    $message .= '<p><small>The ' . theme('placeholder', $db_type) . ' error was: ' . theme('placeholder', $error) . '.</small></p>';
  }

  print theme('maintenance_page', $message);
  exit;
}

function db_is_active() {
  global $active_db;
  return !empty($active_db);
}

function _db_query_callback($match, $init = FALSE) {
  static $args = NULL;
  if ($init) {
    $args = $match;
    return;
  }

  switch ($match[1]) {
    case '%d': // We must use type casting to int to convert FALSE/NULL/(TRUE?)
      return (int) array_shift($args); // We don't need db_escape_string as numbers are db-safe
    case '%s':
      return db_escape_string(array_shift($args));
    case '%%':
      return '%';
    case '%f':
      return (float) array_shift($args);
    case '%b': // binary data
      return db_encode_blob(array_shift($args));
  }
}

function db_placeholders($arguments, $type = 'int') {
  $placeholder = db_type_placeholder($type);
  return implode(',', array_fill(0, count($arguments), $placeholder));
}

define('DB_QUERY_REGEXP', '/(%d|%s|%%|%f|%b)/');

function _db_rewrite_sql($query = '', $primary_table = 'n', $primary_field = 'nid', $args = array()) {
  $where = array();
  $join = array();
  $distinct = FALSE;
  foreach (module_implements('db_rewrite_sql') as $module) {
    $result = module_invoke($module, 'db_rewrite_sql', $query, $primary_table, $primary_field, $args);
    if (isset($result) && is_array($result)) {
      if (isset($result['where'])) {
        $where[] = $result['where'];
      }
      if (isset($result['join'])) {
        $join[] = $result['join'];
      }
      if (isset($result['distinct']) && $result['distinct']) {
        $distinct = TRUE;
      }
    }
    elseif (isset($result)) {
      $where[] = $result;
    }
  }

  $where = empty($where) ? '' : '(' . implode(') AND (', $where) . ')';
  $join = empty($join) ? '' : implode(' ', $join);

  return array($join, $where, $distinct);
}

function db_rewrite_sql($query, $primary_table = 'n', $primary_field = 'nid',  $args = array()) {
  list($join, $where, $distinct) = _db_rewrite_sql($query, $primary_table, $primary_field, $args);

  if ($distinct) {
    $query = db_distinct_field($primary_table, $primary_field, $query);
  }

  if (!empty($where) || !empty($join)) {
    $pattern = '{
      # Beginning of the string
      ^
      ((?P<anonymous_view>
        # Everything within this set of parentheses is named "anonymous view"
        (?:
          [^()]++                   # anything not parentheses
        |
          \( (?P>anonymous_view) \)          # an open parenthesis, more "anonymous view" and finally a close parenthesis.
        )*
      )[^()]+WHERE)
    }x';
    preg_match($pattern, $query, $matches);
    if ($where) {
      $n = strlen($matches[1]);
      $second_part = substr($query, $n);
      $first_part = substr($matches[1], 0, $n - 5) . " $join WHERE $where AND ( ";
      // PHP 4 does not support strrpos for strings. We emulate it.
      $haystack_reverse = strrev($second_part);
      // No need to use strrev on the needle, we supply GROUP, ORDER, LIMIT
      // reversed.
      foreach (array('PUORG', 'REDRO', 'TIMIL') as $needle_reverse) {
        $pos = strpos($haystack_reverse, $needle_reverse);
        if ($pos !== FALSE) {
          // All needles are five characters long.
          $pos += 5;
          break;
        }
      }
      if ($pos === FALSE) {
        $query = $first_part . $second_part . ')';
      }
      else {
        $query = $first_part . substr($second_part, 0, -$pos) . ')' . substr($second_part, -$pos);
      }
    }
    else {
      $query = $matches[1] . " $join " . substr($query, strlen($matches[1]));
    }
  }

  return $query;
}

function db_escape_table($string) {
  return preg_replace('/[^A-Za-z0-9_]+/', '', $string);
}

function db_create_table(&$ret, $name, $table) {
  $statements = db_create_table_sql($name, $table);
  foreach ($statements as $statement) {
    $ret[] = update_sql($statement);
  }
}

function db_field_names($fields) {
  $ret = array();
  foreach ($fields as $field) {
    if (is_array($field)) {
      $ret[] = $field[0];
    }
    else {
      $ret[] = $field;
    }
  }
  return $ret;
}

function db_type_placeholder($type) {
  switch ($type) {
    case 'varchar':
    case 'char':
    case 'text':
    case 'datetime':
      return '\'%s\'';

    case 'numeric':
      // For 'numeric' values, we use '%s', not '\'%s\'' as with
      // string types, because numeric values should not be enclosed
      // in quotes in queries (though they can be, at least on mysql
      // and pgsql).  Numerics should only have [0-9.+-] and
      // presumably no db's "escape string" function will mess with
      // those characters.
      return '%s';

    case 'serial':
    case 'int':
      return '%d';

    case 'float':
      return '%f';

    case 'blob':
      return '%b';
  }

  // There is no safe value to return here, so return something that
  // will cause the query to fail.
  return 'unsupported type ' . $type . 'for db_type_placeholder';
}

---