from sqlalchemy import *
from datetime import datetime
from sqlalchemy.orm import declarative_base,sessionmaker
db_url='mysql+pymysql://root:123456@127.0.0.1:3306/ai0824?charset=utf8'
engine=create_engine(db_url , pool_size=50,echo=True)
Base=declarative_base()
class Scores(Base):
    __tablename__ = 's_scores'
    id=Column(  Integer
               , primary_key=True
               ,autoincrement=True
               ,comment='成绩编号'
              )
    stu_id=Column(Integer
                  ,comment='学生编号'
                 , nullable=False
                 )
    exam_seq=Column(Integer

                    , nullable=True
                   ,comment='考试序次'
                    )
    score=Column(Float
                 ,comment='分数'
                )
    create_date=Column(DATETIME
                       , default=datetime.now
                       ,comment='创建时间'
                      )
    update_date=Column(DATETIME
                       , default=datetime.now
                       ,onupdate=datetime.now
                       ,comment='更新时间'
                       )
    deleted=Column(Integer
                  ,default=1
                   , comment='软删除'
                  )
Base.metadata.create_all(engine)
Session = sessionmaker( bind=engine
                        ,autoflush=False
                        ,autocommit = False
                        )