A unique identifier for this query object. File core/lib/Drupal/Core/Database/Query/SelectExtender.php

public SelectExtender::hasTag($tag)

public SelectExtender::havingCompile(Connection $connection)

public SelectExtender::exists(SelectInterface $select)

public SelectExtender::groupBy($field)

public SelectExtender::forUpdate($set = TRUE)

public SelectExtender::range($start = NULL, $length = NULL)

public SelectExtender::havingIsNotNull($field)

public &SelectExtender::havingConditions()

public SelectExtender::getMetaData($key)