模型操作

① 在models.py中建立數據庫模型

class StudentInfo(models.Model):
  address = models.CharField(max_length=50, null=True)
  phone = models.CharField(max_length=11, null=True)
  
  class Meta:
    db_table = 'stu_info'

class Grade(models.Model):
    g_name = models.CharField(max_length=100, null=True)

   class Meta:
     db_table = 'grade'

class Student(models.Model):
  s_name = models.CharField(max_length=10, unique=True, null=False)
  age = models.IntegerField(default=18)
   # 第一次創建數據時，自動默認為當前創建的時間
  create_time = models.DateTimeField(auto_now_add=True)
   # 修改時自動更新為修改的時間
  operate_time = models.DateTimeField(auto_now=True)
  is_delete = models.BooleanField(default=0)
  chinese = models.DecimalField(max_digits=3, decimal_places=1,null=True)
  math = models.DecimalField(max_digits=3, decimal_places=1,null=True)
  # 一對一字段，一個學生對應一條學生信息
  stuinfo = models.OneToOneField(StudentInfo, related_name='stu', on_delete=models.CASCADE, null=True)  
  # 多對多字段，
  grade = models.ForeignKey(Grade,related_name='stu',on_delete=models.CASCADE, null=True)
  class Meta:
    db_table = 'student'

在views.py中通過學生信息表查找學生信息

def sel_stu_by_info(request):
  if request.method == 'GET':
    stuinfo = StudentInfo.objects.filter(phone = '123456').first()
# 通過django自帶的OneToOneField即可通過related_name自動創建外鍵關系
    stu = stuinfo.stu
  return HttpResponse('查詢成功')

def add_grade(request):
    if request.method == 'GET':
        names = ['python班級', 'Java班級', 'Php班級', 'C++班級']
        for name in names:
            if not Grade.objects.filter(g_name=name).exists():
                Grade.objects.create(g_name=name)
        # 分配班級
        stus = Student.objects.filter(pk__in=[1, 2, 3, 4, 5]).all()
        g = Grade.objects.filter(g_name='python班級').first()
        for stu in stus:
            stu.grade = g
            #stu.grade_id = g.id
            stu.save()
        return HttpResponse('添加班級和學生信息')