1 django.shortcuts import render,HttpResponse
2 from app01.models import *
3 # Create your views here.
4
5 def index(request):
6 return render(request,"index.html")
7
8 def addbook(request):
9 # 一对多的添加
10
11
12
13 # 第一种方式
14 # Book.objects.create(name="Linux运维",price=1133,pub_date="2017-11-22",publish_id=2)
15
16
17
18 # 第二种添加方式 publish_id,没办法添加publish_obj
19 # publish_obj=Publish.objects.filter(name="人民出版社")[0]
20 # print("+++!!!****",publish_obj)
21 # +++!!!**** Publish object (1)
22 # print(type(publish_obj))
23 # <class 'app01.models.Publish'>
24
25 # Book.objects.create(name="GO语言", price=43, pub_date="2017-07-17", publish_id=2)
26 # INSERT INTO `app01_book` (`name`, `price`, `pub_date`, `publis
27 # h_id`) VALUES ('GO语言', 43, '2017-07-17', 2); args=['GO语言', 43, '20
28 # 17-07-17', 2]
29
30
31
32 # 拿到数据库里面的表的值,有两步,先拿到值,再赋给对象
33 # 再从里面取值
34 # 先拿到book表,取到name=python的值,再赋给对象
35 # 如果是两个值,会报错,get只能得到一个值
36 # book_obj=Book.objects.get(name='python')
37 #
38 # print("----",book_obj)
39
40
41
42 # 一对多:book_obj.publish------一定是一个对象
43 # 如果是要取外键的表的值,取publish会取到一个publish对象
44 # print(type(book_obj.publish))
45 # print(book_obj.publish.name)
46 # print(book_obj.publish.city)
47
48
49
50 # 从子表去找主表
51 # 要拿到表中外键的表的值,步骤有
52 # 先拿到publish表是name的值等于机械出版社的一整行对象pub_obj(表中有id,name,city)
53 # SELECT `app01_publish`.`id`, `app01_publish`.`name`, `app01_pu
54 # blish`.`city` FROM `app01_publish` WHERE `app01_publish`.`name` = '机
55 # 械出版社'; args=('机械出版社',)
56 # 把pub_obj结果赋值给publish,由id作为查找依据,再从book表中找到要查询的name跟price
57 # SELECT `app01_book`.`name`, `app01_book`.`price` FROM `app01_b
58 # ook` WHERE `app01_book`.`publish_id` = 4 LIMIT 21; args=(4,)
59
60 # get查找方式:表.objects.get()--只能有一个对象
61 # pub_obj=Publish.objects.get(name='机械出版社')
62
63 # filter查找方式:表.objects.filter()[0]--是对象的集
64 # pub_obj2=Publish.objects.filter(name="山西出版社")[0]
65 # print(pub_obj)
66 # Publish object (4)
67
68 # print(pub_obj.city)
69 # 上海
70 # print(pub_obj.id)
71 # 4
72
73 # 关键点:把publish表的对象放进filter里面筛选,再从里面values取值
74 # ret=Book.objects.filter(publish=pub_obj).values("name","price")
75 # ret2=Book.objects.filter(publish=pub_obj2).values("name","pub_date")
76
77 # print(ret)
78 # print(ret2)
79 # 机械出版社出版的书籍跟价格---query对象
80 # <QuerySet [{'name': 'Java', 'price': 65}, {'name': 'Linux开发', 'price
81 # ': 1133}, {'name': 'Linux系统', 'price': 133}, {'name': 'Linux服务器',
82 # 'price': 133}]>
83
84
85
86 # 从主表再去找子表
87 # ,第一步相同,从publish表找到name等于南方出版社,赋值给pub_obj
88 pub_obj = Publish.objects.filter(name='山西出版社')[0]
89 # 再从pub_obj里面找到book_set.all()(book子表的所有内容) 是一个对象集合
90
91 # publish表拿到了book表的对象,表名+单引号,得到了表名里面的queryset对象.all()的所有值,
92 # book_set.all(),再从里面values取值
93 print(pub_obj.book_set.all())
94 # <QuerySet [<Book: Django>, <Book: Linux运维>, <Book: sqlyog>, <Book: Linux代码>, <Book: GO语言>, <Book: GO语言>, <Book: GO语言>, <Book: moring>]>
95
96 print(pub_obj.book_set.all().values("name",'price'))
97 # <QuerySet [{'name': 'Django', 'price': 45}, {'name': 'Linux运维', 'pri
98 # ce': 1133}, {'name': 'sqlyog', 'price': 1133}, {'name': 'Linux代码', '
99 # price': 133}, {'name': 'GO语言', 'price': 43}, {'name': 'GO语言', 'pri
100 # ce': 43}, {'name': 'GO语言', 'price': 43}, {'name': 'moring', 'price':
101 # 23}]>
102
103 # 更简便的第3种方式:
104 ret=Book.objects.filter()
