Updates a set of records in a concrete data store.
- mixed $query An object which defines the update operation(s) that should be performed against the data store. This can be a `Query`, a `RecordSet`, a `Record`, or a subclass of one of the three. Alternatively, `$query` can be an adapter-specific query string.
- array $options Options to execute, which are defined by the concrete implementation.
Returnsboolean Returns true if the update operation was a success, otherwise false.
abstract public function update($query, array $options = array());