7.x select.inc public SelectQuery::preExecute(SelectQueryInterface $query = NULL)

Generic preparation and validation for a SELECT query.

Return value

TRUE if the validation was successful, FALSE if not.

Overrides SelectQueryInterface::preExecute

1 call to SelectQuery::preExecute()
SelectQuery::execute in includes/database/select.inc
Runs the query against the database.


includes/database/select.inc, line 1221


Query builder for SELECT statements.


public function preExecute(SelectQueryInterface $query = NULL) {
  // If no query object is passed in, use $this.
  if (!isset($query)) {
    $query = $this;

  // Only execute this once.
  if ($query->isPrepared()) {
    return TRUE;

  // Modules may alter all queries or only those having a particular tag.
  if (isset($this->alterTags)) {
    // Many contrib modules assume that query tags used for access-checking
    // purposes follow the pattern $entity_type . '_access'. But this is
    // not the case for taxonomy terms, since core used to add term_access
    // instead of taxonomy_term_access to its queries. Provide backwards
    // compatibility by adding both tags here instead of attempting to fix
    // all contrib modules in a coordinated effort.
    // TODO:
    // - Extract this mechanism into a hook as part of a public (non-security)
    //   issue.
    // - Emit E_USER_DEPRECATED if term_access is used.
    //   https://www.drupal.org/node/2575081
    $term_access_tags = array('term_access' => 1, 'taxonomy_term_access' => 1);
    if (array_intersect_key($this->alterTags, $term_access_tags)) {
      $this->alterTags += $term_access_tags;
    $hooks = array('query');
    foreach ($this->alterTags as $tag => $value) {
      $hooks[] = 'query_' . $tag;
    drupal_alter($hooks, $query);

  $this->prepared = TRUE;

  // Now also prepare any sub-queries.
  foreach ($this->tables as $table) {
    if ($table['table'] instanceof SelectQueryInterface) {

  foreach ($this->union as $union) {

  return $this->prepared;