DjanGo数据库方法

单表的增删改查

增

models.Department.objects.create(title="保安部")

查询所有

 查询所有（查询一个：.first()）
res = models.Department.objects.all()
 <QuerySet [<Department: Department object>, <Department: Department object>]>
for row in res:
 print(row.id, row.title)

查询指定字段(values)

 #select title from department ;
res = models.Department.objects.values("title").all()
### <QuerySet [{'title': '保安部'}, {'title': '开发部'}, {'title': '开发部'}]>
for row in res:
    print(row['title'])

查询指定字段(values_list元组)

# res = models.Department.objects.values_list("title").all()
    # ### <QuerySet [('保安部',), ('开发部',), (' 吧开发部',)]>                                                                                                              
    # print(res)

条件查询filter

 res = models.Department.objects.filter(id__lt = 3)   ### little then（小于3）
 res = models.Department.objects.filter(id__gt = 3)  ###  greater then（大于3）
 取第一条数据
 res = models.Department.objects.all().first()
 print(res)

删

models.Department.objects.filter(id=3).delete()

更新

models.Department.objects.filter(id=2).update(title='xxxx')

一对多表

增

 models.UserInfo.objects.create(uname = "zekai3", age=15, email="dddd@qq.com", ud_id=2)
models.UserInfo.objects.create(uname = "zekai4", age=16, email="gggg@qq.com", ud_id=2)
 models.UserInfo.objects.create(uname = "zekai5", age=18, email="hhhh@qq.com", ud_id=1)

 info = {"uname":'zekai2', 'age':13, "email":'123@qq.com', "ud_id":2}
 models.UserInfo.objects.create(**info)

查

正向查询

res = models.UserInfo.objects.all()
for row in res:
  print(row.id, row.uname, row.age, row.ud.title)

反向查询

### 写法: 小写的表名_set.all()
res = models.Department.objects.all()
for row in  res:
 print(row.title, row.userinfo_set.all())

神奇的双下画线

用用于查询某一个人员的全部信息，包括这个人员在另一个表的外键的属性

res = models.UserInfo.objects.values('id', 'uname', "ud__title").all()
    print(res)

res = models.UserInfo.objects.values_list('id', 'uname', "ud__title").all()
    print(res)