class DatabaseStatementEmpty

Empty implementation of a database statement.

This class satisfies the requirements of being a database statement/result object, but does not actually contain data. It is useful when developers need to safely return an "empty" result set without connecting to an actual database. Calling code can then treat it the same as if it were an actual result set that happens to contain no records.

Hierarchy

class DatabaseStatementEmpty implements \Iterator, DatabaseStatementInterface

Expanded class hierarchy of DatabaseStatementEmpty

File

core/includes/database/database.inc, line 2460: Core systems for the database layer.

View source

class DatabaseStatementEmpty implements Iterator, DatabaseStatementInterface {

  /**
   * {@inheritdoc}
   */
  public function execute($args = array(), $options = array()) {
    return FALSE;
  }

  /**
   * {@inheritdoc}
   */
  public function getQueryString() {
    return '';
  }

  /**
   * {@inheritdoc}
   */
  public function rowCount() {
    return 0;
  }

  /**
   * {@inheritdoc}
   */
  public function setFetchMode($mode, $a1 = NULL, $a2 = array()) {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function fetch($mode = NULL, $cursor_orientation = NULL, $cursor_offset = NULL) {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function fetchField($index = 0) {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function fetchObject() {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function fetchAssoc() {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  public function fetchAll($mode = NULL, $column_index = NULL, $constructor_arguments = array()) {
    return array();
  }

  /**
   * {@inheritdoc}
   */
  public function fetchCol($index = 0) {
    return array();
  }

  /**
   * {@inheritdoc}
   */
  public function fetchAllKeyed($key_index = 0, $value_index = 1) {
    return array();
  }

  /**
   * {@inheritdoc}
   */
  public function fetchAllAssoc($key, $fetch = NULL) {
    return array();
  }

  /* Implementations of Iterator. */

  /**
   * {@inheritdoc}
   */
  #[\ReturnTypeWillChange]
  public function current() {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  #[\ReturnTypeWillChange]
  public function key() {
    return NULL;
  }

  /**
   * {@inheritdoc}
   */
  #[\ReturnTypeWillChange]
  public function rewind() {
    // Nothing to do: our DatabaseStatement can't be rewound.
  }

  /**
   * {@inheritdoc}
   */
  #[\ReturnTypeWillChange]
  public function next() {
    // Do nothing, since this is an always-empty implementation.
  }

  /**
   * {@inheritdoc}
   */
  #[\ReturnTypeWillChange]
  public function valid() {
    return FALSE;
  }
}

Members

Name	Modifiers	Type	Description
DatabaseStatementEmpty::current	public	function
DatabaseStatementEmpty::execute	public	function	Executes a prepared statement Overrides DatabaseStatementInterface::execute
DatabaseStatementEmpty::fetch	public	function
DatabaseStatementEmpty::fetchAll	public	function
DatabaseStatementEmpty::fetchAllAssoc	public	function	Returns the result set as an associative array keyed by the given field. Overrides DatabaseStatementInterface::fetchAllAssoc
DatabaseStatementEmpty::fetchAllKeyed	public	function	Returns the entire result set as a single associative array. Overrides DatabaseStatementInterface::fetchAllKeyed
DatabaseStatementEmpty::fetchAssoc	public	function	Fetches the next row and returns it as an associative array. Overrides DatabaseStatementInterface::fetchAssoc
DatabaseStatementEmpty::fetchCol	public	function	Returns an entire single column of a result set as an indexed array. Overrides DatabaseStatementInterface::fetchCol
DatabaseStatementEmpty::fetchField	public	function	Returns a single field from the next record of a result set. Overrides DatabaseStatementInterface::fetchField
DatabaseStatementEmpty::fetchObject	public	function
DatabaseStatementEmpty::getQueryString	public	function	Gets the query string of this statement. Overrides DatabaseStatementInterface::getQueryString
DatabaseStatementEmpty::key	public	function
DatabaseStatementEmpty::next	public	function
DatabaseStatementEmpty::rewind	public	function
DatabaseStatementEmpty::rowCount	public	function	Returns the number of rows affected by the last SQL statement. Overrides DatabaseStatementInterface::rowCount
DatabaseStatementEmpty::setFetchMode	public	function
DatabaseStatementEmpty::valid	public	function

class DatabaseStatementEmpty

Hierarchy

See also

Related topics

File

Members