Django项目——定义模型&生成数据表

定义模型：
有一个数据表，就对应一个模型
生成数据表

1.在modles.py文件中定义模型

引入from django.db import models
模型类要集成modles.Model类

这里以班级和学生v表为例

from django.db import models
# Create your models here.

class Grades(models.Model):
    gname = models.CharField(max)
    gdate = models.DateField()
    ggirlnum = models.IntegerField()
    gboynum = models.IntegerField()
    isDelete = models.BooleanField(default=False)

class Students (models.Model):
    sname = models.CharField(max_length=20)
    sgender = models.BooleanField(default=True)
    sage = models.IntegerField()
    scontend = models.CharField(max_length=20)
    isDelete = models.BooleanField(default=False)
    #关联外键
    sgrade = models.ForeignKey("Grades")
    

说明：不需要定义主键，主键是在生成时自动添加。

2.生成数据表

生成迁移文件
执行 python3 manage.py makemigrations
在migrations 目录下生成一个迁移文件
执行迁移
执行python3 manage.py migrate

示例：

D:\untitled\0517\project>python3  manage.py makemigrations
Migrations for 'myApp':
  myApp\migrations\0001_initial.py
    - Create model Grades
    - Create model Students

D:\untitled\0517\project>python3 manage.py migrate
Operations to perform:
  Apply all migrations: admin, auth, contenttypes, myApp, sessions
Running migrations:
  Applying myApp.0001_initial... OK

D:\untitled\0517\project>

数据库中已经存在2张表：

image.png