Chris@0: <?php
Chris@0: 
Chris@0: namespace Drupal\Core\Database;
Chris@0: 
Chris@0: /**
Chris@0:  * Empty implementation of a database statement.
Chris@0:  *
Chris@0:  * This class satisfies the requirements of being a database statement/result
Chris@0:  * object, but does not actually contain data.  It is useful when developers
Chris@0:  * need to safely return an "empty" result set without connecting to an actual
Chris@0:  * database.  Calling code can then treat it the same as if it were an actual
Chris@0:  * result set that happens to contain no records.
Chris@0:  *
Chris@0:  * @see \Drupal\search\SearchQuery
Chris@0:  */
Chris@0: class StatementEmpty implements \Iterator, StatementInterface {
Chris@0: 
Chris@0:   /**
Chris@0:    * Is rowCount() execution allowed.
Chris@0:    *
Chris@0:    * @var bool
Chris@0:    */
Chris@0:   public $allowRowCount = FALSE;
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function execute($args = [], $options = []) {
Chris@0:     return FALSE;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function getQueryString() {
Chris@0:     return '';
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function rowCount() {
Chris@0:     if ($this->allowRowCount) {
Chris@0:       return 0;
Chris@0:     }
Chris@0:     throw new RowCountException();
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function setFetchMode($mode, $a1 = NULL, $a2 = []) {
Chris@0:     return;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetch($mode = NULL, $cursor_orientation = NULL, $cursor_offset = NULL) {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchField($index = 0) {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchObject() {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchAssoc() {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchAll($mode = NULL, $column_index = NULL, $constructor_arguments = NULL) {
Chris@0:     return [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchCol($index = 0) {
Chris@0:     return [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchAllKeyed($key_index = 0, $value_index = 1) {
Chris@0:     return [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function fetchAllAssoc($key, $fetch = NULL) {
Chris@0:     return [];
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function current() {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function key() {
Chris@0:     return NULL;
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function rewind() {
Chris@0:     // Nothing to do: our DatabaseStatement can't be rewound.
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function next() {
Chris@0:     // Do nothing, since this is an always-empty implementation.
Chris@0:   }
Chris@0: 
Chris@0:   /**
Chris@0:    * {@inheritdoc}
Chris@0:    */
Chris@0:   public function valid() {
Chris@0:     return FALSE;
Chris@0:   }
Chris@0: 
Chris@0: }