users_group_member_id = Column("users_group_member_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    users_group_id = Column("users_group_id", Integer(), ForeignKey('users_groups.users_group_id'), nullable=False, unique=None, default=None)

    user_id = Column("user_id", Integer(), ForeignKey('users.user_id'), nullable=False, unique=None, default=None)

    user = relationship('User', lazy='joined')

    users_group = relationship('UsersGroup')

    def __init__(self, gr_id='', u_id=''):

        self.users_group_id = gr_id

        self.user_id = u_id

class RepositoryField(Base, BaseModel):

    __tablename__ = 'repositories_fields'

    __table_args__ = (

        UniqueConstraint('repository_id', 'field_key'),  # no-multi field

        {'extend_existing': True, 'mysql_engine': 'InnoDB',

         'mysql_charset': 'utf8'},

    )

    PREFIX = 'ex_'  # prefix used in form to not conflict with already existing fields

    repo_field_id = Column("repo_field_id", Integer(), nullable=False, unique=True, default=None, primary_key=True)

    repository_id = Column("repository_id", Integer(), ForeignKey('repositories.repo_id'), nullable=False, unique=None, default=None)

    field_label = Column("field_label", String(1024, convert_unicode=False, assert_unicode=None), nullable=False)

    field_value = Column("field_value", String(10000, convert_unicode=False, assert_unicode=None), nullable=False)

    field_desc = Column("field_desc", String(1024, convert_unicode=False, assert_unicode=None), nullable=False)

    field_type = Column("field_type", String(256), nullable=False, unique=None)

    created_on = Column('created_on', DateTime(timezone=False), nullable=False, default=datetime.datetime.now)

    repository = relationship('Repository')

    @property

    def field_key_prefixed(self):

        return 'ex_%s' % self.field_key

    @classmethod

    def un_prefix_key(cls, key):

        if key.startswith(cls.PREFIX):

            return key[len(cls.PREFIX):]

        return key

    @classmethod

    def get_by_key_name(cls, key, repo):

        row = cls.query()\

                .filter(cls.repository == repo)\

                .filter(cls.field_key == key).scalar()

        return row