Here's the `posts.py` file for the `blog_app` FastAPI backend, defining a SQLAlchemy model for posts:


from sqlalchemy import Column, ForeignKey, Integer, String, Text
from sqlalchemy.orm import relationship

from app.db import Base

class Post(Base):
    __tablename__ = "posts"

    id = Column(Integer, primary_key=True, index=True)
    title = Column(String, nullable=False)
    content = Column(Text, nullable=False)
    user_id = Column(Integer, ForeignKey("users.id"), nullable=False)

    author = relationship("User", back_populates="posts")

    def __repr__(self):
        return f"Post(id={self.id}, title='{self.title}', content='{self.content[:20]}...')"

This code defines a `Post` model that inherits from the `Base` class provided by SQLAlchemy. The `Post` model has the following fields:

- `user_id`: An integer foreign key referencing the `id` of the `User` model (assuming it exists).