public function Select::preExecute

Generic preparation and validation for a SELECT query.

Return value

TRUE if the validation was successful, FALSE if not.

Overrides SelectInterface::preExecute

File

drupal/core/lib/Drupal/Core/Database/Query/Select.php, line 377

Definition of Drupal\Core\Database\Query\Select

Class

Select

Query builder for SELECT statements.

Namespace

Code

public function preExecute(SelectInterface $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)) {
    $hooks = array(
      'query',
    );
    foreach ($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 SelectInterface) {
      $table['table']
        ->preExecute();
    }
  }
  foreach ($this->union as $union) {
    $union['query']
      ->preExecute();
  }
  return $this->prepared;
}