QoS_SpecsTable.py

class VolumeQOSSpecs(BASE, CinderBase):
    """Represents qos specs as key/value pairs for a volume_type."""
    __tablename__ = 'volume_type_qos_specs'
    id = Column(Integer, primary_key=True)
    key = Column(String(255))
    value = Column(String(255))
    volume_type_id = Column(String(36),
                            ForeignKey('volume_types.id'),
                            nullable=False)
    volume_type = relationship(
        VolumeTypes,
        backref="qos_specs",
        foreign_keys=volume_type_id,
        primaryjoin='and_('                                                                                
        'VolumeTypeQOSSpecs.volume_type_id == VolumeTypes.id,'
        'VolumeTypeQOSSpecs.deleted == False)'
    )