person_table = Table("persons", meta,
    Column('id', Integer, primary_key=True),
    Column('client_id', Integer, ForeignKey(clients.c.id), nullable=False),
    Column('fullname', String(length=255), index=True),
    mysql_engine='InnoDB',
    mysql_charset='utf8'

    )


tasks_table = Table("tasks", meta,
    Column('id', Integer, primary_key=True),
    Column('client_id', Integer, ForeignKey(clients.c.id), nullable=False, index=True),
    Column('type_id', Integer, ForeignKey(tasktypes_table.c.id),
        index=True, nullable=False),
    Column('deal_id', Integer, ForeignKey(deal_table.c.id), index=True),
    Column('minutes', Integer, nullable=False, default=0),
    Column('closed', Boolean, nullable=False, default=False, index=True),
    Column('deleted', Boolean, nullable=False, default=False, index=True),
    Column('alert', Boolean, nullable=False, default=False, index=True),
    Column('address', String(255), nullable=False, default='', index=True),
    Column('time', DateTime),
    Column('has_date', Boolean, nullable=False, default=False),
    Column('has_time', Boolean, nullable=False, default=False),
    Column('descr', Text),
    Column('result', Text, default='', nullable=False),
    mysql_engine='InnoDB',
    mysql_charset='utf8'
    )


tasks_contacts_table = Table('tasks_contacts', meta,
    Column('id', Integer, primary_key=True),
    Column('contact_id', Integer, ForeignKey(person_table.c.id), index=True),
    Column('task_id', Integer, ForeignKey(tasks_table.c.id), index=True),
    UniqueConstraint('contact_id', 'task_id'),
    ForeignKeyConstraint(
        columns=["task_id"], refcolumns=[tasks_table.c.id],
        onupdate="CASCADE", ondelete="CASCADE"),
    ForeignKeyConstraint(
        columns=["contact_id"], refcolumns=[person_table.c.id],
        onupdate="CASCADE", ondelete="CASCADE"),
    mysql_engine='InnoDB',
    mysql_charset='utf8'
    )



mapper(Task, tasks_table, properties={
    'type': relationship(TaskType),
    'contacts': relationship(Person,
        primaryjoin=tasks_contacts_table.c.task_id == tasks_table.c.id,
        secondary=tasks_contacts_table,
        secondaryjoin=person_table.c.id == tasks_contacts_table.c.contact_id)})