PHP SelectInterface::preExecute方法代码示例

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

 /**
  * Generates a hash from a query object, to be used as part of the cache key.
  *
  * This smart caching strategy saves Drupal from querying and rendering to
  * HTML when the underlying query is unchanged.
  *
  * Expensive queries should use the query builder to create the query and then
  * call this function. Executing the query and formatting results should
  * happen in a #pre_render callback.
  *
  * @param \Drupal\Core\Database\Query\SelectInterface $query
  *   A select query object.
  *
  * @return string
  *   A hash of the query arguments.
  */
 public static function keyFromQuery(SelectInterface $query)
 {
     $query->preExecute();
     $keys = array((string) $query, $query->getArguments());
     return hash('sha256', serialize($keys));
 }

 /**
  * Creates a temporary table from a select query.
  *
  * Will return the name of a table containing the item IDs of all results, or
  * FALSE on failure.
  *
  * @param \Drupal\Core\Database\Query\SelectInterface $db_query
  *   The select query whose results should be stored in the temporary table.
  *
  * @return string|false
  *   The name of the temporary table, or FALSE on failure.
  */
 protected function getTemporaryResultsTable(SelectInterface $db_query) {
   // We only need the id field, not the score.
   $fields = &$db_query->getFields();
   unset($fields['score']);
   if (count($fields) != 1 || !isset($fields['item_id'])) {
     $this->getLogger()->warning('Error while adding facets: only "item_id" field should be used, used are: @fields.', array('@fields' => implode(', ', array_keys($fields))));
     return FALSE;
   }
   $expressions = &$db_query->getExpressions();
   $expressions = array();
   $db_query->distinct();
   if (!$db_query->preExecute()) {
     return FALSE;
   }
   $args = $db_query->getArguments();
   return $this->database->queryTemporary((string) $db_query, $args);
 }

 /**
  * Creates a temporary table from a select query.
  *
  * Will return the name of a table containing the item IDs of all results, or
  * FALSE on failure.
  *
  * @param \Drupal\Core\Database\Query\SelectInterface $db_query
  *   The select query whose results should be stored in the temporary table.
  *
  * @return string|false
  *   The name of the temporary table, or FALSE on failure.
  */
 protected function getTemporaryResultsTable(SelectInterface $db_query)
 {
     // We only need the id field, not the score.
     $fields =& $db_query->getFields();
     unset($fields['score']);
     if (count($fields) != 1 || !isset($fields['item_id'])) {
         $this->getLogger()->warning('Error while adding facets: only "item_id" field should be used, used are: @fields.', array('@fields' => implode(', ', array_keys($fields))));
         return FALSE;
     }
     $expressions =& $db_query->getExpressions();
     $expressions = array();
     // If there's a GROUP BY for item_id, we leave that, all others need to be
     // discarded.
     $group_by =& $db_query->getGroupBy();
     $group_by = array_intersect_key($group_by, array('t.item_id' => TRUE));
     $db_query->distinct();
     if (!$db_query->preExecute()) {
         return FALSE;
     }
     $args = $db_query->getArguments();
     try {
         $result = $this->database->queryTemporary((string) $db_query, $args);
     } catch (\PDOException $e) {
         watchdog_exception('search_api', $e, '%type while trying to create a temporary table: @message in %function (line %line of %file).');
         return FALSE;
     }
     return $result;
 }