function pager_query

6.x pager_query($query, $args = array(), $limit = 10, $element = 0, $count_query = NULL, $count_query_select_from = NULL)

Code adapted from Drupal 6:

This helps allow us to create a paginated query (where we have Prev and Next links for the results).

NOTE!!!!!!!!! To render the pager, call the function theme_pager() after getting the results of this query

Description from the Drupal API page:

Use this function when doing select queries you wish to be able to page. The pager uses LIMIT-based queries to fetch only the records required to render a certain page. However, it has to learn the total number of records returned by the query to compute the number of pages (the number of records / records per page). This is done by inserting "COUNT(*)" in the original query. For example, the query "SELECT nid, type FROM node WHERE status = '1' ORDER BY sticky DESC, created DESC" would be rewritten to read "SELECT COUNT(*) FROM node WHERE status = '1' ORDER BY sticky DESC, created DESC". Rewriting the query is accomplished using a regular expression.

Unfortunately, the rewrite rule does not always work as intended for queries that already have a "COUNT(*)" or a "GROUP BY" clause, and possibly for other complex queries. In those cases, you can optionally pass a query that will be used to count the records.

For example, if you want to page the query "SELECT COUNT(*), TYPE FROM node GROUP BY TYPE", pager_query() would invoke the incorrect query "SELECT COUNT(*) FROM node GROUP BY TYPE". So instead, you should pass "SELECT COUNT(DISTINCT(TYPE)) FROM node" as the optional $count_query parameter.

$query: The SQL query that needs paging. $limit: The number of query results to display per page. $element: An optional integer to distinguish between multiple pagers on one page. $count_query: An SQL query used to count matching records.

9 calls to pager_query()
admin_display_watchdog in modules/admin/admin.module
alerts_advisees_alerts_form in modules/alerts/alerts.module
Displays alerts for our various advisees.
alerts_display_advisee_activities_page in modules/alerts/alerts.module
Display all advisee activities since the beginning of time, thanks to pager query.
content_display_content_admin_list in modules/content/content.module
Display a list of content for the administrator
content_public_files_form in modules/content/content.module
This screen lets the user upload/manage/delete "public files" stored at custom/files/content_uploads/public_uploads/

... See full list


includes/, line 173
This file contains mostly db shortcuts.


function pager_query($query, $args = array(), $limit = 10, $element = 0, $count_query = NULL, $count_query_select_from = NULL) {
  global $pager_page_array, $pager_total, $pager_total_items;
  $page = isset($_REQUEST ['page']) ? intval($_REQUEST ['page']) : '';

  // Construct a count query if none was given.
  if (!isset($count_query)) {

    $select_from_replace = 'SELECT COUNT(*) ';
    if ($count_query_select_from) {
      $select_from_replace = $count_query_select_from;

    $count_query = preg_replace(array(
      '/SELECT.*?FROM /As',
      '/ORDER BY .*/',
      '/GROUP BY .*/',
    ), array(
      $select_from_replace . " FROM ",
    ), $query);

  // Convert comma-separated $page to an array, used by other functions.
  $pager_page_array = explode(',', $page);

  // We calculate the total of pages as ceil(items / limit).
  $pager_total_items [$element] = db_result(db_query($count_query, $args));
  $pager_total [$element] = ceil($pager_total_items [$element] / $limit);
  $pager_page_array [$element] = max(0, min((int) $pager_page_array [$element], (int) $pager_total [$element] - 1));

  return db_query_range($query, $args, $pager_page_array [$element] * $limit, $limit);