cherry-ai/backend/app/db/models.py
2025-04-30 04:39:36 +08:00

53 lines
2.3 KiB
Python

# File: backend/app/db/models.py (New - Database models)
# Description: SQLAlchemy ORM 模型定义
from sqlalchemy import Column, String, Float, ForeignKey, Text, DateTime, Integer
from sqlalchemy.orm import relationship
from sqlalchemy.sql import func # For default timestamps
from app.db.database import Base
import uuid
from datetime import datetime, timezone
def generate_uuid():
return str(uuid.uuid4())
class AssistantModel(Base):
__tablename__ = "assistants"
id = Column(String, primary_key=True, default=generate_uuid)
name = Column(String(50), nullable=False, index=True)
description = Column(String(200), nullable=True)
avatar = Column(String(5), nullable=True)
system_prompt = Column(Text, nullable=False)
model = Column(String, nullable=False)
temperature = Column(Float, nullable=False, default=0.7)
created_at = Column(DateTime(timezone=True), server_default=func.now())
updated_at = Column(DateTime(timezone=True), onupdate=func.now())
sessions = relationship("SessionModel", back_populates="assistant", cascade="all, delete-orphan")
class SessionModel(Base):
__tablename__ = "sessions"
id = Column(String, primary_key=True, default=generate_uuid)
title = Column(String(100), nullable=False, default="New Chat")
assistant_id = Column(String, ForeignKey("assistants.id"), nullable=False, index=True)
created_at = Column(DateTime(timezone=True), server_default=func.now())
updated_at = Column(DateTime(timezone=True), onupdate=func.now(), index=True) # Index for sorting
assistant = relationship("AssistantModel", back_populates="sessions")
messages = relationship("MessageModel", back_populates="session", cascade="all, delete-orphan", order_by="MessageModel.created_at") # Order messages by time
class MessageModel(Base):
__tablename__ = "messages"
id = Column(String, primary_key=True, default=generate_uuid)
session_id = Column(String, ForeignKey("sessions.id"), nullable=False, index=True)
sender = Column(String(10), nullable=False) # 'user' or 'ai' or 'system'
text = Column(Text, nullable=False)
order = Column(Integer, nullable=False) # Explicit order within session
created_at = Column(DateTime(timezone=True), server_default=func.now())
session = relationship("SessionModel", back_populates="messages")