app/models.py

from sqlalchemy import Column, ForeignKey, Integer, String, DateTime
from sqlalchemy.orm import relationship
from datetime import datetime

from database import Base

class User(Base):
    __tablename__ = "users"

    id = Column(Integer, primary_key=True, index=True)
    username = Column(String, unique=True, index=True)
    messages = relationship("Message", back_populates="user")

class Message(Base):
    __tablename__ = "messages"

    id = Column(Integer, primary_key=True, index=True)
    user_id = Column(Integer, ForeignKey("users.id"))
    message = Column(String)
    type = Column(String)
    timestamp = Column(DateTime, default=datetime.now)

    user = relationship("User", back_populates="messages")