• ORM,XSS攻击


    1. ORM

     1.1 对表的基本查

       # 单表的查
    
        # 1、查询所有
        res = Class.objects.all() # QuerySet对象,(列表套对象)
        print(res) # <QuerySet [<Class: Class object>, <Class: Class object>, <Class: Class object>, <Class: Class object>]>
        for row in res:
            print(row.id, row.cname)
    
        # 2. 指定字段查询 values, value_list
        res = Class.objects.values('cname').all() # QuerySet对象,(列表套字典)
        print(res) # <QuerySet [{'cname': 'pyton8期'}, {'cname': 'pyton9期'}, {'cname': 'pyton10期'}, {'cname': 'pyton11期'}]>
    
        res = Class.objects.values_list('cname').all()   # QuerySet对象,(列表套元组)
        # print(res)   # <QuerySet [('pyton8期',), ('pyton9期',), ('pyton10期',), ('pyton11期',)]>
    
        # 3、filter 筛选
        res = Class.objects.filter(id=1).all()
        print(res)  # <QuerySet [<Class: Class object>]>
        for row in res:
            print(row.id, row.cname)   # 1 pyton8期
    
        # 4、大于,大于等于,小于,小于等于 __gt, __gte, __lt, __lte
        res = Class.objects.filter(id__lt=3)
        print(res)   # <QuerySet [<Class: Class object>, <Class: Class object>]>
        for row in res:
            print(row.id, row.cname)   # 1 pyton8期    2 pyton9期
    
      # 一对多
        # 1、查询所有
        res = Students.objects.all()  # 列表套对象
        print(res)  # <QuerySet [<Students: Students object>, <Students: Students object>, <Students: Students object>, <Students: Students object>, <Students: Students object>, <Students: Students object>, <Students: Students object>, <Students: Students object>]>
    
        # 2、查询一个
        res = Students.objects.first()
        print(res)   # Students object
        print(res.id, res.sname, res.stu_cla_id)  # 1 富强 1
        #
        # 3、正向查询
        res = Students.objects.all()
        for row in res:
            print(row.id, row.sname, row.stu_cla.cname)
            # 1 富强 pyton8期
            # 2 民主 pyton10期
            # 3 文明 pyton9期
            # ...    ...   ...
    
        # 4、 反向查询 外键关联的表名小写_set.filter()
        # 需求:查询所有课程下的所有学生姓名
        res = Class.objects.all()
        for row in res:
            print(row.cname, row.students_set.all())
    
            for k in row.students_set.all():
                print(row.cname, k.sname)
                # pyton8期 富强
                # pyton8期 公正
                # pyton8期 法治
                # pyton9期 文明
                # pyton9期 平等
                # pyton10期 民主
                # pyton11期 和谐
                # pyton11期 自由
    
        # 5、神奇的双下划线(跨表查询) (列表套字典)
        res = Students.objects.values('sname', 'stu_cla__cname')
        print(res) # <QuerySet [{'sname': '富强', 'stu_cla__cname': 'pyton8期'}, {'sname': '民主', 'stu_cla__cname': 'pyton10期'}, {'sname': '文明', 'stu_cla__cname': 'pyton9期'}, {'sname': '和谐', 'stu_cla__cname': 'pyton11期'}, {'sname': '自由', 'stu_cla__cname': 'pyton11期'}, {'sname': '平等', 'stu_cla__cname': 'pyton9期'}, {'sname': '公正', 'stu_cla__cname': 'pyton8期'}, {'sname': '法治', 'stu_cla__cname': 'pyton8期'}]>
    
    
        # 多对多
        # 查询 老师 zeikai 所教的班级
        # 方式一
        res = Teachers.objects.filter(sname='zekai').first()
        print(res.id, res.sname)   # 1 zekai
        tea_cla_list = res.teacherclass_set.all()
        print('tea_cla_list',tea_cla_list) # <QuerySet [<TeacherClass: TeacherClass object>, <TeacherClass: TeacherClass object>]>
        for obj in tea_cla_list:
            print(obj.cid.cname)
            # pyton8期
            # pyton9期
    
        # 方式二
        res = TeacherClass.objects.filter(tid__sname='zekai').all()
        for obj in res:
            print(obj.cid.cname)
            # pyton8期
            # pyton9期
    
        # 方式三
        res = TeacherClass.objects.filter(tid__sname='zekai').values('cid__cname')
        print(res)   # <QuerySet [{'cid__cname': 'pyton8期'}, {'cid__cname': 'pyton9期'}]>

    1.2 高级查询

    # 高级查询
        # 1、in
        res = Class.objects.filter(id__in = [1,2,3])
        print(res) # <QuerySet [<Class: Class object>, <Class: Class object>, <Class: Class object>]>
        for row in res:
            print(row.id, row.cname)
            # 1 pyton8期
            # 2 pyton9期
            # 3 pyton10期
    
        # 2、 not in
        res = Class.objects.exclude(id__in=[1,2,3])
        print(res)   # <QuerySet [<Class: Class object>]>
        for row in res:
            print(row.id, row.cname)  # 4 pyton11期
    
        # 3、like
        # startswith, istartwith,(不区分大小写)  where name like 'py%' ## 以py开头的所有的数据
        # endswith, iendswith       where  name  like '%py'
        # contains, icontains      包含某一个单词    where name like "%py%"
    
        res = Class.objects.filter(cname__istartswith='py')
        print(res)  # <QuerySet [<Class: Class object>, <Class: Class object>, <Class: Class object>, <Class: Class object>]>
        for row in res:
            print(row.id, row.cname)
            # 1 pyton8期
            # 2 pyton9期
            # 3 pyton10期
            # 4 pyton11期
    
        # 4、between ... and ..
        res = Class.objects.filter(id__range=[1,3])
        print(res)   # <QuerySet [<Class: Class object>, <Class: Class object>, <Class: Class object>]>
    
        # 5、limit 10,20
        res = Class.objects.all()[0:3]   #[ 开始位置: 结束位置]
        print(res)   # <QuerySet [<Class: Class object>, <Class: Class object>, <Class: Class object>]>
    
        # 6、order by age asc, name desc
        res = Class.objects.all().order_by('id', 'cname')   # 默认升序前面加一个 ‘-’ 代表 降序
        print(res.query)    # SELECT "app1_class"."id", "app1_class"."cname" FROM "app1_class" ORDER BY "app1_class"."id" ASC, "app1_class"."cname" ASC
    
        # 7、group by
        from django.db.models import Count, Max, Min, Sum
        res = Class.objects.values('cname').annotate(xxx=Count('id'))
        print(res.query)   # SELECT "app1_class"."cname", COUNT("app1_class"."id") AS "xxx" FROM "app1_class" GROUP BY "app1_class"."cname"
    
        # 8、only: 只取某一列值
        res = Class.objects.only('id', 'cname').all()
        print(res.query) # SELECT "app1_class"."id", "app1_class"."cname" FROM "app1_class"
    
        # 9、defer: 除了这几列之外的所有值 (但是不管怎样, 都会查 id)
        res = Students.objects.defer('id','sname').all()
        print(res.query) # SELECT "app1_students"."id", "app1_students"."stu_cla_id" FROM "app1_students"
    
        # 10、 using: 想要使用哪个数据库, 就将这个数据库的配置名称写到using中
        Class.objects.all().using('xxxx')
    
        # 11、count 表中总共有多少条数据
        res = Class.objects.count()   # count不需要参数
        print(res)
    
        # 12、第一条数据,最后一条数据
        res = Class.objects.first()
        ret = Class.objects.last()
        print(res, ret)  # Class object Class object
        # 
        # 13、 gt 大于 gte: 大于等于   lt 小于   lte 小于等于
        res = Class.objects.filter(id__gt=2)
        print(res)    # <QuerySet [<Class: Class object>, <Class: Class object>]>
    
        # 14、and操作
        res = Class.objects.filter(id=1,cname='pyton8期')
        print(res)   # <QuerySet [<Class: Class object>]>
        print(res.query)   # SELECT "app1_class"."id", "app1_class"."cname" FROM "app1_class" WHERE ("app1_class"."id" = 1 AND "app1_class"."cname" = pyton8期)
    
        # 15、or操作
        from django.db.models import Q
        res = Class.objects.filter(Q(id=2) | Q(cname='pyton8期'))
        print(res.query)  # SELECT "app1_class"."id", "app1_class"."cname" FROM "app1_class" WHERE ("app1_class"."id" = 2 OR "app1_class"."cname" = pyton8期)
    
        # 16、在原来的基础上更新值
        from django.db.models import  F
        UserInfo.objects.update(age=F('age') + 1)  # 表中存在可以需要更新的值,使用方式如此
    
        # 17、原生sql
        # 方式一
        from django.db import connection
        cursor = connection.cursor()
        cursor.execute("select * from app1_class where id=%s", [1,])
        res = cursor.fetchall()
        print(res)  # [(1, 'pyton8期')]
        res = cursor.fetchone()
        print(res)
    
        # 方式二
        res= Class.objects.raw('select * from main.app1_class')
        print(res)   # <RawQuerySet: select * from main.app1_class>
        for row in res:
            print(row.id, row.cname)
            # 1 pyton8期
            # 2 pyton9期
            # 3 pyton10期
            # 4 pyton11期

    1.3 增

    # # 增加一条数据
        Class.objects.create(cname='pyton8期')
    
        # 增加多条数据
        obj = [
            Class(cname='pyton9期'),
            Class(cname='pyton10期'),
            Class(cname='pyton11期'),
        ]
        Class.objects.bulk_create(obj)
    
        obj = [
            Students(sname='富强', stu_cla_id=1),
            Students(sname='民主', stu_cla_id=3),
            Students(sname='文明', stu_cla_id=2),
            Students(sname='和谐', stu_cla_id=4),
            Students(sname='自由', stu_cla_id=4),
            Students(sname='平等', stu_cla_id=2),
            Students(sname='公正', stu_cla_id=1),
            Students(sname='法治', stu_cla_id=1),
        ]
        Students.objects.bulk_create(obj)
    
    
    多对多创建外键
    1. 自己定制
    2. 通过 ManyToManyField() 来生成第三张表
    models.py:
    class Boy(models.Model):
       name = models.CharField(max_length=32, null=True)
       g = models.ManyToManyField('Girl', null=True)
    class Girl(models.Model):
       nick = models.CharField(max_length=32, null=True)

    1.4 删

    # 删除
        # Students.objects.all().delete()
        # Students.objects.filter(sname='法治').delete()
    
    
    
    【注意】
    stu_cla = models.ForeignKey('Class', null=True, on_delete=models.CASCADE)
    
    CASCADE:   设置级联删除
    SET_NULL : 取消级联删除
            

    1.5 改

    Students.objects.filter(id=7).update(sname='发财')

    2. XSS攻击

        2. Xss攻击
    
            全程:跨站脚本(js)攻击
                
                原因:
                    用户输入的内容不可控
                    
                        <script>1.获取用户的cookie 2. 发送这个cookie到黑客的数据库</script>
            views.py:
                            
                msg = []
                def comment(request):
                    if  request.method == 'GET':
                        return render(request, "comment.html")
                    else:
                        comment = request.POST.get('comment')
                        msg.append(comment)
                        return render(request, "comment.html")
    
                def  show(request):
                    return render(request, 'show.html', {"msg":msg})
            
            comment.html:
                <form action="/comment/" method="post">
                    <input type="text" name="comment">
                    <input type="submit" value="提交">
                </form>
            
            show.html:
                    <ul>
                        {% for item in msg %}
                            <li>{{ item | safe }}</li>
                        {% endfor %}
                    </ul>
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  • 原文地址:https://www.cnblogs.com/gouyang/p/11221377.html
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