interface QueryInterface

interface QueryInterface extends AlterableInterface {
    
    /**
     * Gets the ID of the entity type for this query.
     *
     * @return string
     */
    public function getEntityTypeId();
    
    /**
     * Add a condition to the query or a condition group.
     *
     * For example, to find all entities containing both the Turkish 'merhaba'
     * and the Polish 'siema' within a 'greetings' text field:
     * @code
     *   $entity_ids = \Drupal::entityQuery($entity_type)
     *     ->condition('greetings', 'merhaba', '=', 'tr')
     *     ->condition('greetings.value', 'siema', '=', 'pl')
     *     ->execute();
     * @endcode
     *
     * @param $field
     *   Name of the field being queried. It must contain a field name, optionally
     *   followed by a column name. The column can be the reference property,
     *   usually "entity", for reference fields and that can be followed
     *   similarly by a field name and so on. Additionally, the target entity type
     *   can be specified by appending the ":target_entity_type_id" to "entity".
     *   Some examples:
     *   - nid
     *   - tags.value
     *   - tags
     *   - tags.entity.name
     *   - tags.entity:taxonomy_term.name
     *   - uid.entity.name
     *   - uid.entity:user.name
     *   "tags" "is the same as "tags.value" as value is the default column.
     *   If two or more conditions have the same field names they apply to the
     *   same delta within that field. In order to limit the condition to a
     *   specific item a numeric delta should be added between the field name and
     *   the column name.
     *   @code
     *   ->condition('tags.5.value', 'news')
     *   @endcode
     *   This will require condition to be satisfied on a specific delta of the
     *   field. The condition above will require the 6th value of the field to
     *   match the provided value. Further, it's possible to create a condition on
     *   the delta itself by using '%delta'. For example,
     *   @code
     *   ->condition('tags.%delta', 5)
     *   @endcode
     *   will find only entities which have at least six tags. Finally, the
     *   condition on the delta itself accompanied with a condition on the value
     *   will require the value to appear in the specific delta range. For
     *   example,
     *   @code
     *   ->condition('tags.%delta', 0, '>'))
     *   ->condition('tags.%delta.value', 'news'))
     *   @endcode
     *   will only find the "news" tag if it is not the first value. It should be
     *   noted that conditions on specific deltas and delta ranges are only
     *   supported when querying content entities.
     * @param $value
     *   The value for $field. In most cases, this is a scalar and it's treated as
     *   case-insensitive. For more complex operators, it is an array. The meaning
     *   of each element in the array is dependent on $operator.
     * @param $operator
     *   Possible values:
     *   - '=', '<>', '>', '>=', '<', '<=', 'STARTS_WITH', 'CONTAINS',
     *     'ENDS_WITH': These operators expect $value to be a literal of the
     *     same type as the column.
     *   - 'IN', 'NOT IN': These operators expect $value to be an array of
     *     literals of the same type as the column.
     *   - 'BETWEEN': This operator expects $value to be an array of two literals
     *     of the same type as the column.
     * @param $langcode
     *   Language code (optional). If omitted, any translation satisfies the
     *   condition. However, if two or more conditions omit the langcode within
     *   one condition group then they are presumed to apply to the same
     *   translation. If within one condition group one condition has a langcode
     *   and another does not they are not presumed to apply to the same
     *   translation.
     *
     * @return $this
     * @see \Drupal\Core\Entity\Query\andConditionGroup
     * @see \Drupal\Core\Entity\Query\orConditionGroup
     */
    public function condition($field, $value = NULL, $operator = NULL, $langcode = NULL);
    
    /**
     * Queries for a non-empty value on a field.
     *
     * @param $field
     *   Name of a field.
     * @param $langcode
     *   Language code (optional).
     *
     * @return $this
     */
    public function exists($field, $langcode = NULL);
    
    /**
     * Queries for an empty field.
     *
     * @param $field
     *   Name of a field.
     * @param $langcode
     *   Language code (optional).
     *
     * @return $this
     */
    public function notExists($field, $langcode = NULL);
    
    /**
     * Enables a pager for the query.
     *
     * @param $limit
     *   An integer specifying the number of elements per page.  If passed a false
     *   value (FALSE, 0, NULL), the pager is disabled.
     * @param $element
     *   An optional integer to distinguish between multiple pagers on one page.
     *   If not provided, one is automatically calculated.
     *
     * @return $this
     *   The called object.
     */
    public function pager($limit = 10, $element = NULL);
    
    /**
     * @param null $start
     * @param null $length
     * @return $this
     *   The called object.
     */
    public function range($start = NULL, $length = NULL);
    
    /**
     * @param $field
     *   Name of a field.
     * @param string $direction
     * @param $langcode
     *   Language code (optional).
     * @return $this
     *   The called object.
     */
    public function sort($field, $direction = 'ASC', $langcode = NULL);
    
    /**
     * Makes this a count query.
     *
     * For count queries, execute() returns the number entities found.
     *
     * @return $this
     *   The called object.
     */
    public function count();
    
    /**
     * Enables sortable tables for this query.
     *
     * @param $headers
     *   An array of headers of the same structure as described in
     *   template_preprocess_table(). Use a 'specifier' in place of a 'field' to
     *   specify what to sort on. This can be an entity or a field as described
     *   in condition().
     *
     * @return $this
     *   The called object.
     */
    public function tableSort(&$headers);
    
    /**
     * @return $this
     *   The called object.
     */
    public function accessCheck($access_check = TRUE);
    
    /**
     * Execute the query.
     *
     * @return int|array
     *   Returns an integer for count queries or an array of ids. The values of
     *   the array are always entity ids. The keys will be revision ids if the
     *   entity supports revision and entity ids if not.
     */
    public function execute();
    
    /**
     * Creates a new group of conditions ANDed together.
     *
     * For example, consider a drawing entity type with a 'figures' multi-value
     * field containing 'shape' and 'color' columns. To find all drawings
     * containing both a red triangle and a blue circle:
     * @code
     *   $query = \Drupal::entityQuery('drawing');
     *   $group = $query->andConditionGroup()
     *     ->condition('figures.color', 'red')
     *     ->condition('figures.shape', 'triangle');
     *   $query->condition($group);
     *   $group = $query->andConditionGroup()
     *     ->condition('figures.color', 'blue')
     *     ->condition('figures.shape', 'circle');
     *   $query->condition($group);
     *   $entity_ids = $query->execute();
     * @endcode
     *
     * @return \Drupal\Core\Entity\Query\ConditionInterface
     */
    public function andConditionGroup();
    
    /**
     * Creates a new group of conditions ORed together.
     *
     * For example, consider a map entity with an 'attributes' field
     * containing 'building_type' and 'color' columns.  To find all green and
     * red bikesheds:
     * @code
     *   $query = \Drupal::entityQuery('map');
     *   $group = $query->orConditionGroup()
     *     ->condition('attributes.color', 'red')
     *     ->condition('attributes.color', 'green');
     *   $entity_ids = $query
     *     ->condition('attributes.building_type', 'bikeshed')
     *     ->condition($group)
     *     ->execute();
     * @endcode
     * Note that this particular example can be simplified:
     * @code
     *   $entity_ids = $query
     *     ->condition('attributes.color', array('red', 'green'))
     *     ->condition('attributes.building_type', 'bikeshed')
     *     ->execute();
     * @endcode
     *
     * @return \Drupal\Core\Entity\Query\ConditionInterface
     */
    public function orConditionGroup();
    
    /**
     * Queries the current revision.
     *
     * @return $this
     */
    public function currentRevision();
    
    /**
     * Queries the latest revision.
     *
     * The latest revision is the most recent revision of an entity. This will be
     * either the default revision, or a pending revision if one exists and it is
     * newer than the default.
     *
     * @return $this
     */
    public function latestRevision();
    
    /**
     * Queries all the revisions.
     *
     * @return $this
     */
    public function allRevisions();

}