python/Django（增、删、改、查）操作

我们要通过pycharm中的Django模块连接MySQL数据库进行对数据的操作。

一、创建Django项目（每创建一个项目都要进行以下设置）

1、如图所示，创建一个Project

 

2、红色区域是创建的项目名称，蓝色区域是创建目录

 

 3、如上图，把设置中这个注释掉

 

4、在设置文件中设置HTML文件夹路径

5、设置完文件夹路径，创建一个文件夹

二、连接数据库进行操作

建议：创建一个文件夹存放python代码，最后导入到urls.py文件中，如图：

在urls.py文件中设置url和相应的函数：

1 urlpatterns = [2     # url(r'^admin/', admin.site.urls),3     url(r'^classes/', stter.classes),4     url(r'^add_class/', stter.add_class),5     url(r'^del_class/', stter.del_class),6     url(r'^update_class/', stter.update_class),7 ]

查看数据库class表的内容：

from django.shortcuts import render,redirect##导入django模块下的返回方式和跳转模块import pymysql##导入pymysql模块def classes(request):     ##定义查看数据库函数    conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='', database='lian', charset='utf8')    cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)    cursor.execute('select * from class')    class_list = cursor.fetchall()    cursor.close()    conn.close()    return render(request,'classes.html',{
   'class_list':class_list})   　　返回给用户（经过classes.html和用户浏览器渲染内容）{class_list}是传值到html中使用------------------------------------------------------------------------"D:\pycharm\PyCharm 2017.1\bin\runnerw.exe" D:\python3.6\python.exe E:/s4day65/manage.py runserver 8001Performing system checks...System check identified no issues (0 silenced).You have 13 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.Run 'python manage.py migrate' to apply them.June 15, 2017 - 17:08:15Django version 1.11.2, using settings 's4day65.settings'Starting development server at http://127.0.0.1:8001/Quit the server with CTRL-BREAK.===============运行正常================

查看HTML代码：

1  2  3  4     
      5      6  7  8 
班级列表
 9 
     
      10     
      添加11 
     
12 
     
      13     
       14     
        15         
16         
17         
18     
19     
20 21 {% for row in class_list%}     for 循环22     
        23         
24         
25         
30     
31 {% endfor %}      结束for循环  （开始结束一定要共存）32 
      
       
        
ID
        
班级名称
        
操作
       
      
      
       
        
{
   { row.cid }}
        
{
   { row.cname }}
        
26             编辑27             |28             删除29         
       
      
     
33 34 

运行效果：

添加：

1 def add_class(request):   ##定义添加数据库函数 2     if request.method == 'GET': 3         return render(request,'add_class.html') 4     else: 5         print(request.POST) 6         v=request.POST.get('cname') 7         conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='', database='lian', charset='utf8') 8         cursor = conn.cursor() 9         cursor.execute("insert into class(cname) VALUES(%s)",[v,])10         conn.commit()11         cursor.close()12         conn.close()13         return redirect('/classes/')14 ---------------------------------------------------------------15 Performing system checks...16 17 System check identified no issues (0 silenced).18 19 You have 13 unapplied migration(s). Your project may not work properly until you apply the migrations for app(s): admin, auth, contenttypes, sessions.20 Run 'python manage.py migrate' to apply them.21 June 15, 2017 - 17:08:1522 Django version 1.11.2, using settings 's4day65.settings'23 Starting development server at http://127.0.0.1:8001/24 Quit the server with CTRL-BREAK.25 [15/Jun/2017 17:10:00] "GET /classes/ HTTP/1.1" 200 139626 ===============================

添加的HTML代码：

1  2  3  4     
      5      6  7  8 
添加班级
 9 
     
      10     
      
班级名称：
11     
      12 
     
13 14 

运行结果：

 

删除：

1 def del_class(request):         ##定义删除数据库函数2     nid=request.GET.get('nid')3     conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='', database='lian', charset='utf8')4     cursor = conn.cursor()5     cursor.execute("delete from class WHERE cid=%s",[nid,])6     conn.commit()7     cursor.close()8     conn.close()9     return redirect('/classes/')

运行结果：

 修改：

1 def update_class(request): 2     if request.method =='GET': 3         nid = request.GET.get('nid') 4         # name=request.POST.get('cname') 5         conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='', database='lian', charset='utf8') 6         cursor = conn.cursor() 7         cursor.execute("select class.cid,class.cname from class where cid=%s", [nid,]) 8         ste = cursor.fetchone() 9         return render(request, 'update_class.html', {
   'ste': ste})10     else:11         id=request.GET.get('nid')12         name=request.POST.get('cname')13         conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', password='', database='lian', charset='utf8')14         cursor = conn.cursor()15         cursor.execute("update class set cname=%s where cid = %s",[name,id,])16         conn.commit()17         cursor.close()18         conn.close()19         return redirect('/classes/')

修改HTML代码：

    
             
班级修改
    
     
        
      
班级名称：
        
              {
    #    
     
#}        {
   #    {% for row in ste %}#}        {
   #    {
    { row }}#}        {
   #    {% endfor %}#}    

运行效果：