那些年被我坑过的Python——牵一发动全身 第十一章MySQL、ORM

 #!/usr/bin/env python
 # -*- coding:utf-8 -*-
 __Author__ = "Zhang Xuyao"

 from sqlalchemy import create_engine

 # engine = create_engine("mysql+pymysql://root:123123@localhost/attendance?charset=utf8", echo=True)
 engine = create_engine("mysql+pymysql://root:123123@localhost/attendance?charset=utf8")

engine

 #!/usr/bin/env python
 # -*- coding:utf-8 -*-
 __Author__ = "Zhang Xuyao"

 from sqlalchemy.ext.declarative import declarative_base
 from settings import db_settings
 from sqlalchemy import Table, Column, Integer, String, Enum, DATE, ForeignKey, PrimaryKeyConstraint
 from sqlalchemy.orm import relationship

 Base = declarative_base()

 teacherBatch_t = Table('tbt', Base.metadata,
                        Column('batch_name', String(64), ForeignKey('batch.name')),
                        Column('teacher_id', String(64), ForeignKey('teacher.id'))
                        )

 studentBatch_t = Table('sbt', Base.metadata,
                        Column('batch_name', String(64), ForeignKey('batch.name')),
                        Column('student_qq', String(64), ForeignKey('student.qq'))
                        )

 class Teacher(Base):
     __tablename__ = 'teacher'
     id = Column(String(64), primary_key=True)
     name = Column(String(64), nullable=False)
     password = Column(String(64), nullable=False, default='321cba')

     # tstudents = relationship('Student', secondary=task_t, backref='teachers')
     tbatchs = relationship('Batch', secondary=teacherBatch_t, backref='teachers')

     def __repr__(self):
         return self.name

 class Student(Base):
     __tablename__ = 'student'
     qq = Column(String(64), primary_key=True)
     name = Column(String(64), nullable=False)
     password = Column(String(64), nullable=False, default='321cba')

     # steachers = relationship('Teacher', secondary=task_t, backref='students')
     sbatchs = relationship('Batch', secondary=studentBatch_t, backref='students')

     def __repr__(self):
         return self.name

 # 课程批次（班级）name为批次如python14期，courseType为类型如python
 class Batch(Base):
     __tablename__ = 'batch'
     name = Column(String(64), primary_key=True)
     courseType = Column(String(64), nullable=False)

     def __repr__(self):
         return self.name + self.courseType

 class Task(Base):
     __tablename__ = 'task'
     batch_name = Column(String(64), ForeignKey('batch.name'))
     date = Column(DATE, nullable=False)
     student_qq = Column(String(64), ForeignKey('student.qq'))

     status = Column(Enum('at', 'ab', 'va', 'ot'),
                     default='ab', nullable=False)
     score = Column(Integer,
                    default=0, nullable=False)
     teacher_id = Column(String(64), ForeignKey('teacher.id'))

     comment = Column(String(1024))
     task_pk = PrimaryKeyConstraint(batch_name, student_qq, date)

     student = relationship('Student', backref='tasks')
     teacher = relationship('Teacher', backref='tasks')

 # 父类调用所有的子类实现表结构的创建#####

 # Base.metadata.drop_all(db_settings.engine)  # 删除表结构
 Base.metadata.create_all(db_settings.engine)  # 创建表结构

tables relationship

 #!/usr/bin/env python
 # -*- coding:utf-8 -*-
 __Author__ = "Zhang Xuyao"

 from settings import db_tables as dbt
 from settings import db_settings
 from sqlalchemy.orm import sessionmaker
 from sqlalchemy import desc,func
 import datetime

 Session_class = sessionmaker(bind=db_settings.engine)  # 创建与数据库的会话session class ,注意,这里返回给session的是个class,不是实例
 db = Session_class()  # 生成session实例

 def teacherAuth(id, password):
     obj = db.query(dbt.Teacher).filter(dbt.Teacher.id == id).first()
     if not obj:
         return False
     if password == obj.password:
         # print("got it")
         return obj
     else:
         return False

 def studentAuth(qq, password):
     obj = db.query(dbt.Student).filter(dbt.Student.qq == qq).first()
     if not obj:
         return False
     if password == obj.password:
         # print("got it")
         return obj
     else:
         return False

 def addTeacher(id, name, password='abc123'):
     obj = dbt.Teacher(id=id, name=name, password=password)
     db.add(obj)
     db.commit()
     return obj

 def batchBindTeacher(id, name, password):
     pass

 def addStudent(qq, name, password='abc123'):
     obj = dbt.Student(qq=qq, name=name, password=password)
     db.add(obj)
     db.commit()
     return obj

 def batchBindStudent(id, name, password):
     pass

 def addBatch(name, courseType):
     obj = dbt.Batch(name=name, courseType=courseType)
     db.add(obj)
     db.commit()
     return obj

 def addTask(date, score='N/A', status='absent'):
     pass

 if __name__ == '__main__':
     t1 = addTeacher('t001', "Alex", "Alex123")
     t2 = addTeacher('t002', "Jack", "Jack123")
     t3 = addTeacher('t003', "Rain", "Rain123")
     #
     s1 = addStudent('s001', "chenronghua", "abc123")
     s2 = addStudent('s002', "niuhanyang", "abc123")
     s3 = addStudent('s003', "wangsen", "abc123")
     #
     b1 = addBatch("python14", "python")
     b2 = addBatch("pythonS2", "python")
     b3 = addBatch("Ops10", "Linux")

     b1.students = [s1, s2, s3]
     b1.teachers = [t1, t2]

     for i in b1.students:
         obj = dbt.Task(date='2016-10-26', teacher_id=t1.id, student_qq=i.qq, batch_name=b1.name)
         db.add(obj)
         db.commit()
     #
     # obj = db.query(dbt.Teacher).filter(dbt.Teacher.id == "t001").first()
     # for i in obj.tbatchs:
     #     if i.name == 'python14':
     #         for j in i.students:
     #             if j.qq == 's001':
     #                 print(j.name, j.password)

     pass

db handler