如何通过点表示法访问数据

Question

目标:从video_id中提取assessment_obj，赋值给变量

DB类型: SQLAlchemy

模型：Assessment将video_id放在一个多对一的关系中(多个评估可以使用视频)

1.)我试图使用dot.notation从评估2中提取video_id。)这样我就可以使用retrieve方法来提取视频信息(比如url)。

目的:视频url将用于通过JINJA2模板/HTML代码进入视频播放器src。(如果我使用的术语不正确，因为我是新手，并且试图更好地理解这些概念，我很抱歉。)

我试图跟踪一个OOP dot.notation 教程，但不确定如何从表中提取数据并分配给变量，而不会意外地重新分配变量。

views.py

窗体视图配置。

@view_config(route_name='save_assessment_result', renderer='templates/completedpage.jinja2')
def save_assessment_result(request):
    with transaction.manager:
        assessment_id = int(request.params['assessment_id'])
        assessment_obj = api.retrieve_assessment(assessment_id) # the assessment

        assessment_obj.video_id = video # this right? 
        thevid = api.retrieve_video(video) #retrieves the video via ID
        template_video = int(request.params['video'])
        # how do I get the retrieved video 'thevid' into the template? 

        # more code 

       transaction.commit()
       return HTTPCreated()

模板： templates/assessment_form.jinja2

  <div class="embed-responsive embed-responsive-16by9">
    <iframe width="640" height="360" class="embed-responsive-item" allowfullscreen name='video' src="{{ url }}"></iframe>
  </div>

新增:返回assessment_obj。新View_Config.

注：'videoname': video.videoname, 'length': video.length, 'url': video.url

@view_config(route_name='assessment', request_method='GET', renderer='templates/assessment_form.jinja2')
def assessment_form_view(request):
    with transaction.manager:
        assessment_id = int(request.matchdict['id'])
        assessment = api.retrieve_assessment(assessment_id)
        if not assessment:
            raise HTTPNotFound()
        video_id = int(request.matchdict['id']) # <--- this gives the assessmnet_id and not the video
        video = api.retrieve_video(video_id)
        return {'assessment_id': assessment_id, 'assessment_name': assessment.name, 'assessment_text': assessment.text, 'user_id': assessment.user_id, 'video_id':assessment.video_id, 'categories': ','.join([str(i) for i in assessment.categories]), 'video_id':video_id, 'videoname': video.videoname, 'length': video.length, 'url': video.url}

Answer 1

在行assessment_obj.video_id = video中，video变量来自何处？

看到您正在尝试“从表中提取数据并将其赋值给一个变量”，我想知道您是否真的尝试将assessment_obj.video_id赋值给一个名为video的变量。在这种情况下，情况应该是另一种情况：

video = assessment_obj.video_id

然后你的代码几乎开始有意义了。要将数据传递给模板，只需从视图函数返回一个字典：

@view_config(route_name='save_assessment_result', renderer='templates/assessment_form.jinja2')
def save_assessment_result(request):
    with transaction.manager:
        assessment_id = int(request.params['assessment_id'])
        assessment_obj = api.retrieve_assessment(assessment_id) # the assessment

        video_id = assessment_obj.video_id
        thevid = api.retrieve_video(video_id)
        template_video = int(request.params['video'])
        return {
           'thevid': thevid,
           'template_video': template_video
        }

然后，在模板中可以引用这些变量及其成员：

<iframe ... src="{{ thevid.url }}"></iframe>

Answer 2

根据Sergey的惊人指导，我创建了一个新的视图配置，加载了评估和视频。然后，我返回所需的值。

工作代码：

@view_config(route_name='assessment', request_method='GET', renderer='templates/assessment_form.jinja2')
def assessment_form_view(request):
    with transaction.manager:
        assessment_id = int(request.matchdict['id'])
        assessment = api.retrieve_assessment(assessment_id)
        if not assessment:
            raise HTTPNotFound()

        video = assessment.video_id
        print 'test_video_id', video
        video_obj = api.retrieve_video(video)
        print 'test_video_obj', video_obj

        return {'assessment_id': assessment_id, 'assessment_name': assessment.name, 'assessment_text': assessment.text, 'user_id': assessment.user_id, 'categories': ','.join([str(i) for i in assessment.categories]), 'url': video_obj.url, 'video_id':video_obj.video_id, 'videoname': video_obj.videoname, 'length': video_obj.length}