function db_rewrite_sql in Drupal 6

Same name and namespace in other branches

1. 4 includes/database.inc \db_rewrite_sql()
2. 5 includes/database.inc \db_rewrite_sql()

Rewrites node, taxonomy and comment queries. Use it for listing queries. Do not use FROM table1, table2 syntax, use JOIN instead.

Parameters

$query: Query to be rewritten.

$primary_table: Name or alias of the table which has the primary key field for this query. Typical table names would be: {blocks}, {comments}, {forum}, {node}, {menu}, {term_data} or {vocabulary}. However, it is more common to use the the usual table aliases: b, c, f, n, m, t or v.

$primary_field: Name of the primary field.

$args: An array of arguments, passed to the implementations of hook_db_rewrite_sql.

Return value

The original query with JOIN and WHERE statements inserted from hook_db_rewrite_sql implementations. nid is rewritten if needed.

Related topics

42 calls to db_rewrite_sql()

block_list in modules/block/block.module

Return all blocks in the specified region for the current user.

blogapi_mt_validate_terms in modules/blogapi/blogapi.module

Blogging API helper - find allowed taxonomy terms for a node type.

blog_block in modules/blog/blog.module

Implementation of hook_block().

blog_feed_last in modules/blog/blog.pages.inc

Menu callback; displays an RSS feed containing recent blog entries of all users.

blog_feed_user in modules/blog/blog.pages.inc

Menu callback; displays an RSS feed containing recent blog entries of a given user.

... See full list

File

includes/database.inc, line 328

Wrapper for database interface code.

Code

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) {
      $where = '1 = 1';
    }
    if ($matches) {
      $n = strlen($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);
    }
    else {
      $haystack_reverse = strrev($query);
    }

    // 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.
        $pos += 5;
        break;
      }
    }
    if ($matches) {
      if ($pos === FALSE) {
        $query = $first_part . $second_part . ')';
      }
      else {
        $query = $first_part . substr($second_part, 0, -$pos) . ')' . substr($second_part, -$pos);
      }
    }
    elseif ($pos === FALSE) {
      $query .= " {$join} WHERE {$where}";
    }
    else {
      $query = substr($query, 0, -$pos) . " {$join} WHERE {$where} " . substr($query, -$pos);
    }
  }
  return $query;
}