SQLAlchemy Hybrid Comparator

Question

Ich habe ein Modell wie unten beschrieben. Was ich versuche zu tun, ist die native Fähigkeit, eine .filter_by(api_key=$key) zu tun, die von allem, was ich sammeln kann, erfordert die Verwendung eines Komparators. Das heißt, ich konnte nicht ganz dorthin gelangen.

Ist ein Komparator, was ich bin, und wenn ja, was mache ich in diesem Fall falsch?

class ApiKey(hs_base, HomestackDatabase): 
""" 
Class that represents our API Keys table 
""" 

__tablename__ = 'ApiKeys' 

# int: API key id 
api_key_id  = Column(INTEGER(unsigned=True), primary_key=True) 

# int: User id for this key 
user_id   = Column(INTEGER(unsigned=True), ForeignKey("Users.user_id"), nullable=False) 

# bin: A UUID in binary format 
_api_key  = Column('api_key', BINARY(16), unique=True, nullable=False, default=lambda: str(uuid4()).replace('-', '').decode('hex')) 

# str: brief description for usage of this key 
description  = Column(VARCHAR(255)) 

# datetime: The time the record was originally created 
created   = Column(DATETIME, default=datetime.utcnow, nullable=False, index=True) 

# object: Convienience relationship to our User class 
user   = relationship("User") 


class ApiKeyComparator(Comparator): 
    """ 
    provides an __eq__() method that will run against both sides of the expression 
    when we're trying to filter_by(api_key=something) 
    """ 
    def __init__(self, api_key): 
     self.api_key = api_key.replace('-', '').decode('hex') 

    def __eq__(self, other): 
     return self.api_key == other.replace('-', '').decode('hex') 

@hybrid_property 
def api_key(self): 
    return str(UUID(self._api_key.encode("hex"))) 

@api_key.comparator 
def api_key(cls): 
    return ApiKey.ApiKeyComparator(cls._api_key) 

@api_key.setter 
def api_key(self, apikey): 
    self._api_key = api_key.replace('-', '').decode('hex') 

Answer 1

Stellt sich heraus, dass das Lesen schwer ist.

In der ApiKey Klasse, ersetzen von class ApiKeyComparator... mit den folgenden.

class ApiKeyComparator(Comparator): 
    """ 
    provides an __eq__() method that will run against both sides of the expression 
    when we're trying to filter_by(api_key=something) 
    http://docs.sqlalchemy.org/en/latest/orm/extensions/hybrid.html#building-custom-comparators 
    """ 
    def __eq__(self, other): 
     return self.__clause_element__() == other.replace('-', '').decode('hex') 

@hybrid_property 
def api_key(self): 
    return str(UUID(self._api_key.encode("hex"))) 

@api_key.comparator 
def api_key(cls): 
    return ApiKey.ApiKeyComparator(cls._api_key)