Helper function for db_rewrite_sql.

Collects JOIN and WHERE statements via hook_db_rewrite_sql() Decides whether to select primary_key or DISTINCT(primary_key)

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, in most cases the usual table alias (b, c, f, n, m, t or v) is used instead of the table name.

$primary_field: Name of the primary field.

$args: Array of additional arguments.

Return value

An array: join statements, where statements, field or DISTINCT(field).

Related topics

File

drupal-6.x/includes/database.inc, line 281

Wrapper for database interface code.

Code

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);
}