Flask - SQLAlchemy - Bir GUID (BINARY (16)) birincil anahtar olarak eklendikten sonra hata

Question

Ekleme deyimi gerçekleştirdikten sonra bir hata alıyorum.

class Tag(db.Model): 
    __tablename__ = "tags" 
    guid_tag  = db.Column(db.BINARY(16), primary_key=True) 
    id_project = db.Column(db.Integer,db.ForeignKey("projects.id_project")) 
    project  = db.relationship(Proyecto, backref=db.backref('list_tags', lazy='dynamic')) 
    type  = db.Column(db.Integer) #(0,hub);(1,cable);(2,pipe);(3,electrical_pipes) 
    created_at = db.Column(db.DateTime) 
    updated_at = db.Column(db.DateTime) 

    def __init__(self,guid_tag,project,type,created_at): 
     self.guid_tag = guid_tag 
     self.project = project 
     self.type = type 
     self.created_at = created_at 
     self.updated_at = created_at 

takın deyimi

guid_tag = func.UNHEX(args['guid_tag']) 
nuevo_tag = Tag(guid_tag,id_project,type,creado_en) 
db.session.add(nuevo_tag) 
db.session.commit() 

mesaj hatası

File "/Users/Ricardo/PycharmProjects/virtual_rfwire/lib/python3.3/site-packages/sqlalchemy/orm/loading.py", line 647, in load_scalar_attributes "contain a full primary key." % state_str(state)) sqlalchemy.exc.InvalidRequestError: Instance cannot be refreshed - it's not persistent and does not contain a full primary key.

Bu sahneler

2016-03-22 05:56:57,838 INFO sqlalchemy.engine.base.Engine INSERT INTO tags (guid_tag, id_project, type, created_at, updated_at) VALUES (UNHEX(%(UNHEX_1)s), %(id_project)s, %(type)s, %(created_at)s, %(updated_at)s) 
2016-03-22 05:56:57,838 INFO sqlalchemy.engine.base.Engine {'created_at': datetime.datetime(2016, 3, 22, 4, 56, 57, 836091), 'UNHEX_1': '110E8400E29B11D4A716446655440000', 'id_project': 1, 'updated_at': datetime.datetime(2016, 3, 22, 4, 56, 57, 836091), 'type': 0} 

Answer 1

ben bir ekleme beyanda bulunmaya iyi bir yol yayınlayacağız arkasında meydana olduğunu.

import binascii 
guid_tag = binascii.unhexlify(args['guid_tag']) 
nuevo_tag = Tag(guid_tag,id_project,type,creado_en) 
db.session.add(nuevo_tag) 
db.session.commit()