Merge/back_wzy/models/post.py

# models/post.py
from extensions import db
from datetime import datetime

# association table for Post <-> Tag
post_tags = db.Table(
    'post_tags',
    db.Column('post_id', db.Integer, db.ForeignKey('posts.id', ondelete='CASCADE'), primary_key=True),
    db.Column('tag_id', db.Integer, db.ForeignKey('tags.id', ondelete='CASCADE'), primary_key=True)
)

class Post(db.Model):
    __tablename__ = 'posts'

    id = db.Column(db.Integer, primary_key=True)
    user_id = db.Column(db.Integer, db.ForeignKey('users.id', ondelete='CASCADE'), nullable=False)
    topic_id = db.Column(db.Integer, db.ForeignKey('topics.id', ondelete='SET NULL'))
    type = db.Column(db.Enum('text', 'image', 'video', 'document'), default='text', nullable=False)
    title = db.Column(db.String(255), nullable=False)
    content = db.Column(db.Text, nullable=False)
    media_urls = db.Column(db.JSON)
    status = db.Column(db.Enum('draft', 'pending', 'published', 'deleted', 'rejected'),
                       default='draft', nullable=False)
    heat = db.Column(db.Integer, default=0, nullable=False)
    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
    updated_at = db.Column(db.DateTime, default=datetime.utcnow,
                           onupdate=datetime.utcnow, nullable=False)

    # relationships
    tags = db.relationship('Tag', secondary=post_tags, backref=db.backref('posts', lazy='dynamic'))
    behaviors = db.relationship('Behavior', backref='post', lazy='dynamic', cascade='all, delete')
    comments = db.relationship('Comment', backref='post', lazy='dynamic', cascade='all, delete')