Python sqlalchemy.ext.declarative.DeclarativeMeta() Examples

def decode(obj):
        if obj and isinstance(obj.__class__, DeclarativeMeta):
            fields = {}
            for field in [x for x in dir(obj) if not x.startswith('_') and not x.endswith('_') and x != 'metadata']:
                data = obj.__getattribute__(field)
                if isinstance(data, datetime.datetime):
                    fields[field] = data.timestamp()
                elif isinstance(data, datetime.date):
                    fields[field] = data.isoformat()
                elif isinstance(data, datetime.timedelta):
                    fields[field] = (datetime.datetime.min + data).time().isoformat()
                elif isinstance(data, int) or isinstance(data, float) or isinstance(data, str):
                    fields[field] = data
                elif isinstance(data, enum.Enum):
                    fields[field] = data.value
                elif isinstance(data.__class__, DeclarativeMeta):
                    fields[field] = AlchemyEncoder.decode(data)
                elif isinstance(data, list):
                    fields[field] = [AlchemyEncoder.decode(d) for d in data]
            return fields
        else:
            return obj 

def __init__(
        self,
        settings: SQLAlchemySettings,
        base: DeclarativeMeta = Base,
        tables: Optional[Sequence] = None,
        connection_strategy: str = "plain",
        session: Optional[Union[Session, scoped_session]] = None,
    ):
        super(SQLAlchemyDatastore, self).__init__(settings=settings)
        self._was_session_created_here = False
        self._session = session
        if session:
            self._engine: Optional[Engine] = session.get_bind()
        else:
            self._engine = None
        self._base = base
        self._tables = tables
        self._connection_strategy = connection_strategy 

def get_schemas(provider: str) -> List[DeclarativeMeta]:
    """
    get domain schemas supported by the provider

    :param provider:
    :type provider:
    :return:
    :rtype:
    """
    schemas = []
    for provider1, dbs in zvt_context.provider_map_dbnames.items():
        if provider == provider1:
            for dbname in dbs:
                schemas1 = zvt_context.dbname_map_schemas.get(dbname)
                if schemas1:
                    schemas += schemas1
    return schemas 

def __init__(self, model: DeclarativeMeta, writable_properties=True, **handler_settings):
        """ Init CRUD helper

        :param model: The model to work with
        :param handler_settings: Settings for the MongoQuery used to make queries
        """
        self.model = model
        self.handler_settings = handler_settings
        self.bags = self._MODEL_PROPERTY_BAGS_CLS.for_model(model)
        self.reusable_mongoquery = Reusable(self._MONGOQUERY_CLS(self.model, handler_settings))  # type: MongoQuery

        # Settings
        self.writable_properties = writable_properties

        # We also need `legacy_fields`
        # we're going to ignore them in the input
        self.legacy_fields = self.reusable_mongoquery.handler_project.legacy_fields 

def for_model(cls, model: DeclarativeMeta) -> 'ModelPropertyBags':
        """ Get bags for a model.

        Please use this method over __init__(), because it initializes those bags only once
        """
        # The goal of this method is to only initialize a ModelPropertyBags only once per model.
        # Previously, we used to store them inside model attributes.

        try:
            # We want ever model class to have its own ModelPropertyBags,
            # and we want no one to inherit it.
            # We could use model.__dict__ for this, but classes in Python 3 use an immutable `mappingproxy` instead.
            # Thus, we have to keep our own cache of ModelPropertyBags.
            return cls.__bags_per_model_cache[model]
        except KeyError:
            cls.__bags_per_model_cache[model] = bags = cls(model)
            return bags 

def __init__(self,
                 Model: DeclarativeMeta,
                 entity_dict: dict,
                 *,
                 ordinal_number: int = None,
                 pk_names: Sequence[str] = None):
        super().__init__(entity_dict)
        self.Model = Model
        self.ordinal_number = ordinal_number

        # Primary key names: use the provided list; get it ourselves if not provided
        if not pk_names:
            _, pk_names = model_primary_key_columns_and_names(Model)

        # The primary key tuple
        try:
            self.primary_key_tuple = tuple(entity_dict[pk_field]
                                           for pk_field in pk_names)
            self.has_primary_key = True
        # If any of the primary key fields has raised a KeyError, assume that no PK is defined
        except KeyError:
            self.has_primary_key = False
            self.primary_key_tuple = None 

def validate_related_settings(self, bags: mongosql.ModelPropertyBags):
        """ Validate the settings for related entities.

            This method only validates the keys for "related" and "related_models".

            :raises KeyError: Invalid keys
        """
        # Validate "related": all keys must be relationship names
        invalid_keys = set(self._nested_relation_settings.keys()) - bags.relations.names - {'*'}
        if invalid_keys:
            raise KeyError('Invalid relationship name provided to "related": {!r}'
                           .format(list(invalid_keys)))

        # Validated "related_models": all keys must be models, not names
        invalid_keys = set(v
                           for v in self._nested_model_settings.keys()
                           if not isinstance(v, DeclarativeMeta))
        invalid_keys -= {'*'}
        if invalid_keys:
            raise KeyError('Invalid related model object provided to "related_models": {!r}'
                           .format(list(invalid_keys))) 

def default(self, o):
        if isinstance(o, datetime.datetime):
            # d = datetime_safe.new_datetime(o)
            # return d.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))
            return o.strftime("%s %s" % (self.DATE_FORMAT, self.TIME_FORMAT))
        elif isinstance(o, datetime.date):
            # d = datetime_safe.new_date(o)
            return o.strftime(self.DATE_FORMAT)
        elif isinstance(o, datetime.time):
            return o.strftime(self.TIME_FORMAT)
        elif isinstance(o, decimal.Decimal):
            return str(o)
        elif isinstance(o, ResultProxy):
            return list(o)
        elif isinstance(o, RowProxy):
            return dict(o)
        elif isinstance(o.__class__, DeclarativeMeta):
            fields = {}
            instance_dict = o.__dict__
            for field in instance_dict:
                if not field.startswith('_'):
                    fields[field] = instance_dict[field]
            return fields
        else:
            return super(AwareJSONEncoder, self).default(o) 

def to_dict(self, rel=None, backref=None):
        if rel is None:
            rel = self.RELATIONSHIPS_TO_DICT
        res = {column.key: getattr(self, attr)
               for attr, column in self.__mapper__.c.items()}
        if rel:
            for attr, relation in self.__mapper__.relationships.items():
                # Avoid recursive loop between to tables.
                if backref == relation.table:
                    continue
                value = getattr(self, attr)
                if value is None:
                    res[relation.key] = None
                elif isinstance(value.__class__, DeclarativeMeta):
                    res[relation.key] = value.to_dict(backref=self.__table__)
                else:
                    res[relation.key] = [i.to_dict(backref=self.__table__)
                                         for i in value]
        return res 

def to_dict(self, rel=None, backref=None):
        if rel is None:
            rel = self.RELATIONSHIPS_TO_DICT

        res = {
            column.key: self.custom_encoding(attr)
            for attr, column in self.__mapper__.c.items()
        }

        if self.__mapper__.relationships.items():
            for attr, relation in self.__mapper__.relationships.items():
                # Avoid recursive loop between to tables.
                if backref == relation.table:
                    continue
                value = getattr(self, attr)
                if value is None:
                    res[relation.key] = None
                elif isinstance(value.__class__, DeclarativeMeta):
                    res[relation.key] = value.to_dict(backref=self.__table__)
                else:
                    res[relation.key] = [
                        i.to_dict(backref=self.__table__) for i in value
                    ]
        return res 

def sqlalchemy_user_db() -> AsyncGenerator[SQLAlchemyUserDatabase, None]:
    Base: DeclarativeMeta = declarative_base()

    class User(SQLAlchemyBaseUserTable, Base):
        first_name = Column(String, nullable=True)

    DATABASE_URL = "sqlite:///./test-sqlalchemy-user.db"
    database = Database(DATABASE_URL)

    engine = sqlalchemy.create_engine(
        DATABASE_URL, connect_args={"check_same_thread": False}
    )
    Base.metadata.create_all(engine)

    await database.connect()

    yield SQLAlchemyUserDatabase(UserDB, database, User.__table__)

    Base.metadata.drop_all(engine) 

def sqlalchemy_user_db_oauth() -> AsyncGenerator[SQLAlchemyUserDatabase, None]:
    Base: DeclarativeMeta = declarative_base()

    class User(SQLAlchemyBaseUserTable, Base):
        first_name = Column(String, nullable=True)

    class OAuthAccount(SQLAlchemyBaseOAuthAccountTable, Base):
        pass

    DATABASE_URL = "sqlite:///./test-sqlalchemy-user-oauth.db"
    database = Database(DATABASE_URL)

    engine = sqlalchemy.create_engine(
        DATABASE_URL, connect_args={"check_same_thread": False}
    )
    Base.metadata.create_all(engine)

    await database.connect()

    yield SQLAlchemyUserDatabase(
        UserDBOAuth, database, User.__table__, OAuthAccount.__table__
    )

    Base.metadata.drop_all(engine) 

def get_db_name(data_schema: DeclarativeMeta) -> str:
    """
    get db name of the domain schema

    :param data_schema:
    :type data_schema:
    :return:
    :rtype:
    """
    for db_name, base in zvt_context.dbname_map_base.items():
        if issubclass(data_schema, base):
            return db_name 

def table_name_to_domain_name(table_name: str) -> DeclarativeMeta:
    """
    the rules for table_name -> domain_class

    :param table_name:
    :type table_name:
    :return:
    :rtype:
    """
    parts = table_name.split('_')
    domain_name = ''
    for part in parts:
        domain_name = domain_name + part.capitalize()
    return domain_name 

def get_schema_by_name(name: str) -> DeclarativeMeta:
    """
    get domain schema by the name

    :param name:
    :type name:
    :return:
    :rtype:
    """
    for schema in zvt_context.schemas:
        if schema.__name__ == name:
            return schema 

def get_schema_columns(schema: DeclarativeMeta) -> object:
    """
    get all columns of the domain schema

    :param schema:
    :type schema:
    :return:
    :rtype:
    """
    return schema.__table__.columns.keys() 

def for_model_or_alias(cls, target: Union[DeclarativeMeta, AliasedClass]) -> 'ModelPropertyBags':
        """ Get bags for a model, or aliased(model) """
        if inspect(target).is_aliased_class:
            return cls.for_alias(target)
        else:
            return cls.for_model(target) 

def from_entity_dicts(cls,
                          Model: DeclarativeMeta,
                          entity_dicts: Sequence[dict],
                          *,
                          preprocess: callable = None,
                          pk_names: Sequence[str] = None) -> Sequence['EntityDictWrapper']:
        """ Given a list of entity dicts, create a list of EntityDictWrappers with ordinal numbers

        If any dicts are already wrapped with EntityDictWrapper, it's not re-wrapped;
        but be careful to maintain their ordinal numbers, or the client will have difficulties!

        Example:

            _, pk_names = model_primary_key_columns_and_names(Model)
            entity_dicts = EntityDictWrapper.from_entity_dicts(models.User, [
                {'id': 1, 'login': 'kolypto'},
                {         'login': 'vdmit11'},
            ], pk_names=pk_names)
        """
        # Prepare the list of primary key columns
        if not pk_names:
            _, pk_names = model_primary_key_columns_and_names(Model)

        # Generator: EntityDictWrappers with ordinal numbers
        return [entity_dict
                if isinstance(entity_dict, EntityDictWrapper) else
                cls(Model, entity_dict, ordinal_number=i, pk_names=pk_names)
                for i, entity_dict in enumerate(entity_dicts)]

    # Object states 

def filter_many_objects_by_list_of_primary_keys(Model: DeclarativeMeta, entity_dicts: Sequence[dict]) -> BinaryExpression:
    """ Build an expression to load many objects from the database by their primary keys

    This function uses SQL tuples to build an expression which looks like this:

        SELECT * FROM users WHERE (uid, login) IN ((1, 'vdmit11'), (2, 'kolypto'));

    Example:

        entity_dicts = [
            {'id': 1, ...},
            {'id': 2, ...},
            ...
        ]
        ssn.query(models.User).filter(
            filter_many_objects_by_list_of_primary_keys(models.User, entity_dicts)
        )

    Args:
        Model: the model to query
        entity_dicts: list of entity dicts to pluck the PK values from

    Returns:
        The condition for filter()

    Raises:
        KeyError: one of `entity_dicts` did not contain a full primary key set of fields
    """
    pk_columns, pk_names = model_primary_key_columns_and_names(Model)

    # Build the condition: (primary-key-tuple) IN (....)
    # It uses sql tuples and the IN operator: (pk_col_a, pk_col_b, ...) IN ((val1, val2, ...), (val3, val4, ...), ...)
    # Thanks @vdmit11 for this beautiful approach!
    return sql_tuple(*pk_columns).in_(
        # Every object is represented by its primary key tuple
        tuple(entity_dict[pk_field] for pk_field in pk_names)
        for entity_dict in entity_dicts
    ) 

def model_primary_key_columns_and_names(Model: DeclarativeMeta) -> (Sequence[Column], List[str]):
    """ Get the list of primary columns and their names as two separate tuples

    Example:

        pk_columns, pk_names = model_primary_key_columns_and_names(models.User)
        pk_columns  # -> (models.User.id, )
        pk_names  # -> ('id', )
    """
    pk_columns: Sequence[Column] = inspect(Model).primary_key
    pk_names: List[str] = [col.key for col in pk_columns]
    return pk_columns, pk_names 

def aliased(self, model: DeclarativeMeta) -> 'MongoQuery':
        """ Make a query to an aliased model instead.

        This is used by MongoJoin handler to issue subqueries.
        Note that the method modifies the current object and does not make a copy!

        Note: should always be called after as_relation_of(), not before!

        :param model: Aliased model
        """
        # Aliased bags
        self.bags = self.bags.aliased(model)
        self.model = model

        # Aliased loader interface
        # Currently, our join path looks like this: [..., User]
        # Now, when we're using an alias instead, we have to replace that last element with an alias too
        # SqlAlchemy 1.2.x used to work well without doing it;
        # SqlAlchemy 1.3.x now requires adapting a relationship by using of_type() on it.
        # See: https://github.com/sqlalchemy/sqlalchemy/issues/4566
        if self._join_path:  # not empty
            # Okay. First. Replace the last element on the join path with the aliased model's relationship
            new_join_path = self._join_path[0:-1] + (self._join_path[-1].of_type(model),)
            # Second. Apply the new join path
            self.as_relation(new_join_path)
        else:  # empty
            self._as_relation = Load(self.model)  # use the alias

        # Aliased handlers
        for handler_name in self.HANDLER_ATTR_NAMES:
            setattr(self, handler_name,
                    getattr(self, handler_name).aliased(model))

        return self 

def default(self, obj):
    if isinstance(obj.__class__, DeclarativeMeta):
      # an SQLAlchemy class
      fields = {}
      for field in [x for x in dir(obj) if not x.startswith('_') and x != 'metadata']:
        data = obj.__getattribute__(field)
        try:
          json.dumps(data) # this will fail on non-encodable values, like other classes
          fields[field] = data
        except TypeError:
          fields[field] = None
          # a json-encodable dict
      return fields

    return json.JSONEncoder.default(self, obj) 

def default(self, obj, **kwargs):
        """
            override the default json encoding
            :param obj: object to be encoded
            :return: encoded/serizlaized object
        """
        if obj is Included:
            return Included.encode()
        if isinstance(obj, Included):
            result = obj.encode()
            return result
        if isinstance(obj, SAFRSBase):
            result = obj._s_jsonapi_encode()
            return result
        if isinstance(obj, datetime.datetime):
            return obj.isoformat(" ")
        if isinstance(obj, (datetime.date, datetime.time)):
            return obj.isoformat()
        if isinstance(obj, set):
            return list(obj)
        if isinstance(obj, DeclarativeMeta):
            return self.sqla_encode(obj)
        if isinstance(obj, SAFRSFormattedResponse):
            return obj.to_dict()
        elif isinstance(obj, UUID):  # pragma: no cover
            return str(obj)
        if isinstance(obj, decimal.Decimal):  # pragma: no cover
            return str(obj)
        if isinstance(obj, bytes):  # pragma: no cover
            safrs.log.warning("bytes obj, override SAFRSJSONEncoder")
            return obj.hex()

        # We shouldn't get here in a normal setup
        # getting here means we already abused safrs... and we're no longer jsonapi compliant
        if not is_debug():  # pragma: no cover
            # only continue if in debug mode
            safrs.log.warning('JSON Encoding Error: Unknown object type "{}" for {}'.format(type(obj), obj))
            return {"error": "SAFRSJSONEncoder invalid object"}

        return self.ghetto_encode(obj) 

def _encode_object(o):
    """Encode date/time and decimal types, and also ResultProxy/RowProxy
    of SQLAlchemy.
    """

    DATE_FORMAT = "%Y-%m-%d"
    TIME_FORMAT = "%H:%M:%S"

    if type(o) in (list, tuple):
        return [_encode_object(i) for i in o]
    elif type(o) in (int, long, float, str, unicode, bool, dict, None):
        return o
    elif isinstance(o, datetime.datetime):
        return o.strftime("%s %s" % (DATE_FORMAT, TIME_FORMAT))
    elif isinstance(o, datetime.date):
        return o.strftime(DATE_FORMAT)
    elif isinstance(o, datetime.time):
        return o.strftime(TIME_FORMAT)
    elif isinstance(o, decimal.Decimal):
        return str(o)
    elif isinstance(o, ResultProxy):
        return _encode_object(list(o))
    elif isinstance(o, RowProxy):
        return dict(o)
    elif isinstance(o.__class__, DeclarativeMeta):
        fields = {}
        instance_dict = o.__dict__
        for field in instance_dict:
            if not field.startswith('_'):
                fields[field] = instance_dict[field]
        return fields
    else:
        return o 

def make_declarative_base(self, model, metadata=None):
        """Creates the declarative base that all models will inherit from.

        :param model: base model class (or a tuple of base classes) to pass
            to :func:`~sqlalchemy.ext.declarative.declarative_base`. Or a class
            returned from ``declarative_base``, in which case a new base class
            is not created.
        :param: metadata: :class:`~sqlalchemy.MetaData` instance to use, or
            none to use SQLAlchemy's default.

        .. versionchanged 2.3.0::
            ``model`` can be an existing declarative base in order to support
            complex customization such as changing the metaclass.
        """
        if not isinstance(model, DeclarativeMeta):
            model = declarative_base(
                cls=model,
                name='Model',
                metadata=metadata,
                metaclass=DefaultMeta
            )

        # if user passed in a declarative base and a metaclass for some reason,
        # make sure the base uses the metaclass
        if metadata is not None and model.metadata is not metadata:
            model.metadata = metadata

        if not getattr(model, 'query_class', None):
            model.query_class = self.Query

        model.query = _QueryProperty(self)
        return model 

def should_set_tablename(cls):
    """Determine whether ``__tablename__`` should be automatically generated
    for a model.

    * If no class in the MRO sets a name, one should be generated.
    * If a declared attr is found, it should be used instead.
    * If a name is found, it should be used if the class is a mixin, otherwise
      one should be generated.
    * Abstract models should not have one generated.

    Later, :meth:`._BoundDeclarativeMeta.__table_cls__` will determine if the
    model looks like single or joined-table inheritance. If no primary key is
    found, the name will be unset.
    """
    if (
        cls.__dict__.get('__abstract__', False)
        or not any(isinstance(b, DeclarativeMeta) for b in cls.__mro__[1:])
    ):
        return False

    for base in cls.__mro__:
        if '__tablename__' not in base.__dict__:
            continue

        if isinstance(base.__dict__['__tablename__'], declared_attr):
            return False

        return not (
            base is cls
            or base.__dict__.get('__abstract__', False)
            or not isinstance(base, DeclarativeMeta)
        )

    return True 

def default(self, obj):
        from sqlalchemy.ext.declarative import DeclarativeMeta

        if isinstance(obj.__class__, DeclarativeMeta):
            # don't re-visit self
            if obj in self._visited_objs:
                return None
            # do not append if this is a type instance
            if obj.entity_type != 'Type':
                self._visited_objs.append(obj)

            # an SQLAlchemy class
            fields = {}
            for field in [x for x in dir(obj) if not x.startswith('_') and x != 'metadata']:
                # skip ignore fields
                if field in self.ignore_fields:
                    continue

                # skip callables
                if callable(obj.__getattribute__(field)):
                    continue

                try:
                    fields[field] = obj.__getattribute__(field)
                except (AttributeError, TypeError, NotImplementedError, RuntimeError):
                    pass

            # a json-encodable dict
            return fields

        try:
            return json.JSONEncoder.default(self, obj)
        except TypeError:
            return None 

def make_declarative_base(self, model, metadata=None):
        if not isinstance(model, DeclarativeMeta):
            model = declarative_base(
                cls=model, name="Model", metadata=metadata, metaclass=CombinedMeta
            )
        if metadata is not None and model.metadata is not metadata:
            model.metadata = metadata

        if not getattr(model, "query_class", None):
            model.query_class = self.Query

        model.query = _QueryProperty(self)
        return model 

def default(self, obj):
        if isinstance(obj.__class__, DeclarativeMeta):
            return obj.to_dict()
        return super(CustomJSONEncoder, self).default(obj) 

def default(self, obj):
        # print("obj.__class__", obj.__class__, "isinstance(obj.__class__, DeclarativeMeta)", isinstance(obj.__class__, DeclarativeMeta))
        if isinstance(obj.__class__, DeclarativeMeta):
            # an SQLAlchemy class
            fields = {}
            for field in [x for x in dir(obj) if not x.startswith('_') and x != 'metadata']:
                data = obj.__getattribute__(field)
                try:
                    json.dumps(data)     # this will fail on non-encodable values, like other classes
                    fields[field] = data
                except TypeError:    # 添加了对datetime的处理
                    print(data)
                    if isinstance(data, datetime):
                        fields[field] = data.isoformat()
                    elif isinstance(data, date):
                        fields[field] = data.isoformat()
                    elif isinstance(data, timedelta):
                        fields[field] = (datetime.min + data).time().isoformat()
                    else:
                        fields[field] = None
            # a json-encodable dict
            return fields
        elif isinstance(obj, date):
            return json.dumps(date_2_str(obj))

        return json.JSONEncoder.default(self, obj)