千呼万唤始出来~~~当当当,终于系统讲了django的ORM操作啦!!!这里记录的是django操作数据库表一对多.多对多的表创建及操作.对于操作,我们只记录连表相关的内容,介绍增加数据和查找数据,因为能查到就可以用常规方法进行修改,怎么加进来就怎么删掉,都是大同小异,就不再赘述了~~~ 一对多 class UserType(models.Model): caption = models.CharField(max_length=32) class UserInfo(models.Model):
环境准备: 表结构 from django.db import models # Create your models here. class Publisher(models.Model): id = models.AutoField(primary_key=True) name = models.CharField(max_length=) class Book(models.Model): id = models.AutoField(primary_key=True) name = mod
1.查询 完整的查询语句 select [distinct] {* | 字段 | 聚合函数 | 表达式}from 表名 where 筛选数据,过滤数据 group by 分组,为了让聚合函数统计 having 分完组后过滤的条件 order by 字段名,字段名(字段名后面再加字段名) desc | asc
model.py from django.db import models # Create your models here. class Book(models.Model): nid = models.AutoField(primary_key=True) title = models.CharField(max_length=64) publishDate = models.DateField() price = models.DecimalField(max_digits=5, dec