当前位置：网站首页>Example of single table query in ORM student management system

Example of single table query in ORM student management system

2022-07-24 18:08:00 【Full stack programmer webmaster】

Hello everyone , I meet you again , I'm your friend, Quan Jun .

Preparatory work

First, create a project

One ： You have to use MySQL Create a library

because ORM Only tables and data can be processed , So the library must be created by itself

create  database  mysite;

Two : Make the relevant configuration

 In the project mysite Of settings.py In file

One ：

Two ：

3、 ... and ：

Four ：

5、 ... and ：

3、 ... and Create table

We must pay attention to two points ：

 stay app/models.py Create a class in the file , Corresponding to the library in the database , The class name is the library name

 The created class must inherit models.Model

Four ： Linked database

 In the project __init__.py Import in file pymysql

5、 ... and ： Execute relevant orders

 stay PyCharm Click on the bottom Terminal Execute the following two commands ：

1：python manage.py makemigrations    Record 

2：python manage.py migrate   translate

Formally write the program

Table structure

class Class(models.Model):
    id = models.AutoField(primary_key=True)  #  Primary key 
    cname = models.CharField(max_length=32)  #  Class name 
    first_day = models.DateField()  #  Opening time

Query class

URL part ：

url(r'^class_list/$', views.class_list, name="class_list"),

View part ：

def class_list(request):
    class_list = models.Class.objects.all()
    return render(request, "class_list.html", {"class_list": class_list})

HTML part ：

<table border="1">
  {% for class in class_list %}
    <tr>
    <td>{{ forloop.counter }}</td>
    <td>{{ class.id }}</td>
    <td>{{ class.cname }}</td>
    <td>{{ class.first_day|date:'Y-m-d' }}</td>
    </tr>
  {% endfor %}
</table>

New classes

URL part ：

url(r'^add_class/$', views.add_class, name="add_class"),

View part ：

def add_class(request):
    #  front end POST Fill in the new class information 
    if request.method == "POST":
        cname = request.POST.get("cname")
        first_day = request.POST.get("first_day")
        #  You can also get the submitted data in this way , But it is not recommended to write so 
        # data = request.POST.dict()
        # del data["csrfmiddlewaretoken"]
        #  There are two ways to create new data 
        # new_class = models.Class(cname=cname, first_day=first_day)
        # new_class.save()
        models.Class.objects.create(cname=cname, first_day=first_day)
        #  Jump to class_list
        return redirect(reverse('class_list'))
    #  Return to the page of adding classes 
    return render(request, "add_class.html")

HTML part ：

Add a... On the class list page a label ：

<a href="{% url 'add_class' %}"> New page add </a>

Add new page ：

Be careful {% csrf_token %} and date Type of input label .

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="x-ua-compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title> Add class </title>
</head>
<body>
<form action="{% url 'add_class' %}" method="post">
  {% csrf_token %}
  <p> Class name ：<input type="text" name="cname"></p>
  <p> Start date ：<input type="date" name="first_day"></p>
  <p> Submit <input type="submit"></p>
</form>
</body>
</html>

Delete class

URL part ：

url(r'^delete_class/$', views.delete_class, name="delete_class"),

View part ：

def delete_class(request):
    class_id = request.GET.get("class_id")
    models.Class.objects.filter(id=class_id).delete()
    return redirect(reverse("class_list"))

HTML part ：

Add or delete in the table on the class list page .

<a href="{% url 'delete_class' %}?class_id={{ class.id }}"> Delete </a>

Edit class

URL part ：

url(r'^edit_class/$', views.edit_class, name="edit_class"),

View part ：

def edit_class(request):
    if request.method == "POST":
        class_id = request.POST.get("id")
        cname = request.POST.get("cname")
        first_day = request.POST.get("first_day")
        models.Class.objects.create(id=class_id, cname=cname, first_day=first_day)
        return redirect(reverse("class_list"))
    class_id = request.GET.get("class_id")
    class_obj = models.Class.objects.filter(id=class_id)
    if class_obj:
        class_obj = class_obj[0]
        return render(request, "edit_class.html", {"class": class_obj})
    #  The record cannot be found 
    else:
        return redirect(reverse("class_list"))

HTML part ：

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="x-ua-compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title> Edit class </title>
</head>
<body>
<form action="{% url 'edit_class' %}" method="post">
  {% csrf_token %}
  <input type="text" value="{{ class.id }}" style="display: none">
  <p> Class name ：<input type="text" name="cname" value="{{ class.cname }}"></p>
  <p> Start date ：<input type="date" name="first_day" value="{{ class.first_day|date:'Y-m-d' }}"></p>
  <p> Submit <input type="submit"></p>
</form>
</body>
</html>

Publisher ： Full stack programmer stack length , Reprint please indicate the source ：https://javaforall.cn/124474.html Link to the original text ：https://javaforall.cn

原网站

版权声明
本文为[Full stack programmer webmaster]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/203/202207211150282593.html