zoukankan      html  css  js  c++  java
  • Django的ORM查询(学生成绩查询)

    db_column 和 to_field共用

    from django.db import models
    
    # Create your models here.
    
    class Student(models.Model):
        class Mate:
            db_table = 'students'
    
        student_id = models.AutoField(primary_key=True)
        name = models.CharField(unique=True, max_length=30, verbose_name='姓名')
        age = models.PositiveSmallIntegerField(verbose_name='年龄')
    
        def __repr__(self):
            return '{} {}'.format(self.name, self.age)
    
        __str__ = __repr__
    
    class Score(models.Model):
        class Mate:
            db_table = 'scroes'
    
        score_id = models.AutoField(primary_key=True)
        subject = models.CharField(max_length=40, verbose_name='科目')
        score = models.PositiveSmallIntegerField(verbose_name='分数')
        name = models.ForeignKey(Student, db_column='name', to_field='name', on_delete=models.CASCADE)
    
        def __repr__(self):
            return '{} {} {}'.format(self.subject, self.score, self.name)
    
        __str__ = __repr__

    插入数据

    stu1 = Student(1, '王一涵', 10)
    sco1 = Score(1, '语文', 90, '王一涵')
    stu1.save()
    sco1.save()
  • 相关阅读:
    mysql随手记
    Exception 和 RuntimeException区别
    数据结构与算法
    Idea快捷键
    eclipse快捷键
    了解Lua语言中的_index,newindex,rawget和rawset
    Cocos2d-x CCNotificationCenter 通知中心
    LUA-赋值语句
    CCOrbitCamera:create
    类型和值
  • 原文地址:https://www.cnblogs.com/soymilk2019/p/15134003.html
Copyright © 2011-2022 走看看