Structural class representing one item in an order vector.

See PhabricatorQueryOrderVector for discussion of order vectors. This represents one item in an order vector, like "id". When combined with the other items in the vector, a complete ordering (like "name, id") is described.

Construct an item using newFromScalar():

$item = PhabricatorQueryOrderItem::newFromScalar('id');

This class is primarily internal to the query infrastructure, and most application code should not need to interact with it directly.