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#! /usr/bin/env python
# -*- coding: utf-8 -*-
from sqlalchemy import Column, ForeignKey, Integer, String
from sqlalchemy.orm import relationship
from bootstrap import db
class Tag(db.Model):
id = db.Column(db.Integer(), primary_key=True)
text = Column(String, unique=False)
obj = db.Column(db.String, default='article')
user_id = db.Column(db.Integer(), db.ForeignKey('user.id'), nullable=False)
__mapper_args__ = {
'polymorphic_on': obj
}
def __init__(self, text):
self.text = text
class ArticleTag(Tag):
__mapper_args__ = {
'polymorphic_identity': 'article'
}
id = db.Column(db.Integer, db.ForeignKey('tag.id', ondelete='CASCADE'),
primary_key=True)
# relationships
article_id = Column(Integer, ForeignKey('article.id', ondelete='CASCADE'),
nullable=False)
article = relationship('Article', back_populates='tag_objs',
foreign_keys=[article_id])
class BookmarkTag(Tag):
__mapper_args__ = {
'polymorphic_identity': 'bookmark'
}
id = db.Column(db.Integer, db.ForeignKey('tag.id', ondelete='CASCADE'),
primary_key=True)
# relationships
bookmark_id = Column(Integer, ForeignKey('bookmark.id', ondelete='CASCADE'),
nullable=False)
bookmark = relationship('Bookmark', back_populates='tag_objs',
foreign_keys=[bookmark_id])
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