"""数据库连接"""
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker

from .config import settings

engine = create_engine(
    settings.DATABASE_URL,
    pool_pre_ping=True,
    echo=settings.DEBUG
)

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

Base = declarative_base()

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