模拟学生管理系统，创建mysql数据库。
在这里插入图片描述
由于我是在Ubuntu虚拟机打的代码，数据库也在虚拟机上，
mysql,默认只有本机可以访问，远程需要注释掉这一句
etc/mysql/mysql.con.d/mysql.cnf 当前版本是mysql 5.7
#不同版本路径可能不一样，网上有的是“/etc/my.cnf，
注释这一行：bind-address=127.0.0.1 ==> #bind-address=127.0.0.1

重启: service mysqld restart
service mysql restart (5.5.7版本命令)
service 启动：
[root@localhost /]# service mysqld start (5.0版本是mysqld)
[root@szxdb etc]# service mysql start (5.5.7版本是mysql)
/etc/inint.d/mysqld start
停止：service mysqld stop

查询

**
一直在urls.py上写函数是不行的，需要整理好对应的文件夹
创建文件夹及文件mysite – app01 --views.py
urls.py添加

from app01 import views   #加载文件夹，下面调用函数才能找到
urlpatterns = [
    #path('admin/', admin.site.urls),
    path('login/',login),
    path('index/',index),
    #url(r'^class/',views.classes),  这个是以前版本，path是新版本的
    path('classes/',views.classes),
    path('add_class/',views.add_class),
]

views.py

from django.shortcuts import HttpResponse,render,redirect   #导入模块
import pymysql


def classes(request):
    # 创建连接
    conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='root', db='pydata',charset='utf8')
    # 创建游标
    cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
    cursor.execute("select id,title from class")
    class_list = cursor.fetchall()
    # 提交，不然无法保存新建或者修改的数据
    conn.commit()
    # 关闭游标
    cursor.close()
    # 关闭连接
    conn.close()
    #print(class_list)
    return render(request,'classes.html',{'class_list':class_list})

下面如没说明修改，则为添加的函数

创建html文件,mystie – templates – classes.html

<div>
    <a href="/add_class/">添加</a>{{ add_se }}
</div>
<table border="1" >
    <thead>
        <tr>
            <th>班级ID</th>
            <th>班级名称</th>
            <th>操作</th>
        </tr>
    </thead>
    <tbody>
    {% for  msg in class_list  %}
        <tr>
        <td>{{ msg.id }}</td>
        <td>{{ msg.title }}</td><td><a href="">编辑</a> | <a href="/del_class/?nid={{ msg.id }}">删除</a></td>
        </tr>
    {% endfor %}
    </tbody>
</table>
</body>

添加

views.py

def add_class(request):
    if request.method == 'GET':
        return render(request, 'add_class.html')
    else:
        v = request.POST.get('title')   #add_class提交的name="title"的数据
        if len(v)>0:  #如果提交的数据不为空，才能就行操作，否则返回"班级名称不能为空"
            conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='root', db='pydata', charset='utf8')
            cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
            cursor.execute("insert into class(title) values (%s)",[v,])
            conn.commit()
            cursor.close()
            conn.close()
            return redirect('/classes/')
        else:
            return render(request, 'add_class.html',{'msg': '班级名称不能为空'})

删除

def del_class(request):
    nid = request.GET.get('nid')
    conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='root', db='pydata', charset='utf8')
    cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
    cursor.execute("delete from class where id=%s", [nid, ])
    conn.commit()
    cursor.close()
    conn.close()
    return redirect('/classes/')

urls.py的 urlpatterns，增加：path(‘del_class/’,views.del_class),

编辑

新建mysite – templates --edit.html

<body>
<h1>编辑班级</h1>
    <form method="post" action="/edit_class/">
        <p>班级ID：{{ result.id }}</p>
        <input  style="display: none" name="id" value="{{ result.id }}" />
{#        style="display: none" 不显示  显示但不可修改的ID值 #}
        <p>班级名称：<input type="text" name="title" value="{{ result.title }}" /></p>
        <input type="submit" value="提交">
    </form>
</body>

urls.py的 urlpatterns，增加：path(‘edit_class/’,views.edit_class),

views.py增加函数

def edit_class(request):
    if request.method == "GET":
        nid = request.GET.get('nid')
        conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='root', db='pydata', charset='utf8')
        cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
        cursor.execute("select id ,title from class where id = %s", [nid, ])
        result = cursor.fetchone()  #conn.commit()有传值替换这个
        #print(result)
        cursor.close()
        conn.close()
        return render(request, 'edit_class.html', {'result': result})
    else:
        nid = request.POST.get('id')
        title = request.POST.get('title')
        print(nid,title)
        conn = pymysql.connect(host='127.0.0.1', port=3306, user='root', passwd='root', db='pydata', charset='utf8')
        cursor = conn.cursor(cursor=pymysql.cursors.DictCursor)
        cursor.execute("update class set title= %s where id = %s", [title, nid, ])
        conn.commit()
        cursor.close()
        conn.close()
        return redirect('/classes/')