from sqlalchemy import create_engine, MetaData
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from app.settings import DATABASE_URL

# 创建SQLAlchemy引擎
engine = create_engine(DATABASE_URL)

# 创建元数据对象
metadata = MetaData()

# 创建会话工厂
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 创建基类
Base = declarative_base()

# 依赖项：获取数据库会话
def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()