Django learning day 3 (02)
content
- Class Student Table Association Concept
- url routing
- Defining Student Expansion Table Classes
- Define the add student method
- Add student front-end rendering page
- Write a method to get the students corresponding to the expansion table
- Through student information, get his/her family information
Class Student Table Association Concept
1. One-to-one - 1-1 - OneToOneField
The primary key and foreign key are in a one-to-one relationship. In the association table, only the id of one main table can be associated.
Expand the table to find the
main Extended table information: main table object. model_name of the associated table
2. One-to-many - 1-n - see next introduction
3. Many-to-many - m-n - see next introduction
4.on_delete on_delete=models.PROTECT The main table is deleted, and the slave table cannot be deleted. The
default cascade, on_delete=models.CASCADE is deleted from the main table, and the slave table is also deleted
. set_null The main table is deleted, and the associated field of the slave table is set to empty
protect protected , cannot be deleted
url routing
from django.conf.urls import url
from stu import views
urlpatterns = [
# 创建学生信息
url(r'^add_students/', views.add_students),
]Defining Student Expansion Table Classes
class StudentInfo(models.Model):
s_addr = models.CharField(max_length=100)
# 与学生关联的，一对一
stu = models.OneToOneField(Student)
class Meta:
db_table = 'stu_info'Define the add student method
def add_students(request):
if request.method == 'GET':
return render(request, 'add_students.html')
if request.method == 'POST':
# 创建学生信息
s_name = request.POST.get('name')
s_gender = 1 if request.POST.get('gender') else 0
s_birth = request.POST.get('birth')
s_tel = request.POST.get('tel')
s_Chinese = request.POST.get('Chinese')
s_math = request.POST.get('math')
Student.objects.create(
s_name = s_name,
s_gender = s_gender,
s_birth = s_birth,
s_tel = s_tel,
s_Chinese = s_Chinese,
s_math = s_math
)
return render(request, 'add_students.html')Add student front-end rendering page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>添加学生信息</title>
</head>
<body>
<form action="/stu/add_students/" method="post">
<table>
<tr>
<td>姓名</td>
<td>性别</td>
<td>生日</td>
<td>电话</td>
<td>语文</td>
<td>数学</td>
</tr>
<tr>
<td><input type="text" name="name"></td>
<td><input type="text" name="gender"></td>
<td><input type="date" name="birth"></td>
<td><input type="text" name="tel"></td>
<td><input type="text" name="Chinese"></td>
<td><input type="text" name="math"></td>
</tr>
</table>
<input type="submit" value="提交">
</form>
</body>
</html>Write a method to get the students corresponding to the expansion table
Find student information by expanding the student's address
url(r'^search_stu/', views.search_stu),1. Writing method one, but generally not written in this way, you need to search the database twice, and you will be beaten by the boss
def search_stu(request):
# 通过拓展表学生的地址，来查找学生信息
# 查找addr=北京的学生信息
# 写法一， 但一般不这么写，需要查找2次数据库，会被老板打
# stus = StudentInfo.objects.filter(s_addr='北京')
# stu = stus[0]
# search_stu = Student.objects.filter(id=stu.id)
# return render(request, 'search_stu.html', {'search_stu': search_stu})<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
{% for i in search_stu %}
姓名：{{ i.s_name }}
{% endfor %}
</body>
</html>2. Writing method 2
stus = StudentInfo.objects.filter(s_addr__contains='北京')
stu = stus[0]
search_stu = stu.stu
return render(request, 'search_stu.html', {'search_stu': search_stu})This query does not require iteration, all remove the for loop in the html page
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
姓名：{{ search_stu.s_name }}
</body>
</html>Through student information, get his/her family information
stu = Student.objects.filter(s_name='白百合').first()
search_stu = StudentInfo.objects.filter(id=stu.id)
# search_stu = StudentInfo.objects.filter(stu_id=stu.id)
return render(request, 'search_stu.html', {'search_stu': search_stu})<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
</head>
<body>
{% for i in search_stu %}
地址：{{ i.s_addr }}
{% endfor %}
</body>
</html>