from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker,declarative_base

# 导入.env参数
import os
from dotenv import load_dotenv
load_dotenv( )
DB_USER = os.getenv("DB_USER", "root")
DB_PASSWORD = os.getenv("DB_PASSWORD", "")
DB_HOST = os.getenv("DB_HOST", "localhost")
DB_PORT = os.getenv("DB_PORT", "3306")
DB_NAME = os.getenv("DB_NAME", "student_manage_system")

class_management_rul = f"mysql+pymysql://{DB_USER}:{DB_PASSWORD}@{DB_HOST}:{DB_PORT}/{DB_NAME}?charset=utf8mb4"

engine = create_engine(class_management_rul)
SessionLocal = sessionmaker(bind=engine,autocommit=False, autoflush=False)
Base = declarative_base()

# 获取数据库会话依赖

def get_db():
    db = SessionLocal()
    try :
        yield db
    finally:
        db.close()