Google App Engine 数据存储 Jinja2 查询未显示答案

【问题标题】：Google App Engine Datastore Jinja2 Query Not showing upGoogle App Engine 数据存储 Jinja2 查询未显示
【发布时间】：2026-02-18 23:35:02
【问题描述】：

有什么问题？文章被存储在 articleArchive 实体中，但我无法让它显示在我的 HTML 中。 html 中的 where id=article 是我希望查询显示的位置。谢谢！

Python 代码：

import os
import jinja2
import webapp2
import time

from google.appengine.ext import db

template_dir = os.path.join(os.path.dirname(__file__), 'templates')
jinja_env = jinja2.Environment(loader = jinja2.FileSystemLoader(template_dir),
                                                autoescape = True)

#CREATE DATABASE ENTITIY/CHART CLASS to store all articles, titles,
# subheadings, dates posted, author names, article ID, tags, etc. 
class articleArchive(db.Model): 
    title = db.StringProperty(required = True)
    article = db.TextProperty(required = True)
    author = db.StringProperty(required = True)
    datetime = db.DateTimeProperty(auto_now_add = True)


class Handler(webapp2.RequestHandler):
    def write(self, *a, **kw):
        self.response.out.write(*a, **kw)

    def render_str(self, template, **params):
        t = jinja_env.get_template(template)
        return t.render(params)

    def render(self, template, **kw):
        self.write(self.render_str(template, **kw))

class homePage(Handler):
    def get(self):
        self.render("homePage.html")

class submitPage(Handler): 
    def render_post(self, error="", title="", article="", author=""): 
        articles = db.GqlQuery("SELECT * FROM articleArchive ORDER BY datetime DESC")
        self.render("submit.html",  error=error, title=title, article=article, author=author)

    def get(self): 
        self.render_post()

    def post(self): 
        title = self.request.get("title")
        article = self.request.get("article")
        author = self.request.get("author")

        if title and article and author: 
            a = articleArchive(title = title, author = author, article = article)
            a.put()
            self.redirect("/submit")

        else: 
            error = "The title, author, and article fields must be filled out. "
            self.render_post(error, title, article, author)

class singlePost(Handler): 
    def post(self): 
        self.render(submit.html)

app = webapp2.WSGIApplication([('/', homePage), 
                            ('/submit', submitPage),
                            ('/id', singlePost)
                            ],
                                debug=True)

HTML：

{% extends "base.html" %}
<!DOCTYPE html>

<html>
    <head>
        {% block head %}
        <title>Submit a Post!</title>
        <link type="text/css" rel="stylesheet" href="/stylesheets/submit.css">
        {% endblock %}
    </head>

    <body>
        {% block content %}

            <h1>Article Submission</h1>

            <form method="post" id="lol">
                <label>
                    <div>Title</div>
                    <input type="text" name="title" value={{title}}>
                </label>

                <br>
                <br>

                <label>
                    <div>Author</div>
                    <input type="text" name="author" value={{author}}>
                </label>

                <br>
                <br>

                <label>
                    <div>Article</div>
                    <textarea type="text" name="article" form="lol" value={{article}}></textarea>
                </label>

                <div class="error">{{error}}</div>

                <input type="submit">
            </form>

            <div id = "article">
                {% for article in articles %}
                    <h1> {{article.title}} </h1>
                    <h2> {{article.author}} </h2>
                    <h3> {{article.datetime}} </h3>
                    <br>
                    <pre> {{article.article}} </pre>
                    <hr>
                {% endfor %}
            </div>

        {% endblock %}
    </body>
</html>

【问题讨论】：

您正在渲染“文章”，并且正在循环浏览“文章”，请注意缺少“s”。
哪里缺少“s”？我不明白错误是什么。不过，我很感谢您的回复！
如果你刚刚开始，你应该从 db 切换到 ndb 。它是访问数据存储的更好 API。

标签： python html google-app-engine jinja2

【解决方案1】：

您的 render_post 函数正在查询并分配给 articles，但您正在将函数 kwarg article 传递给您的 render 函数。这意味着在您的 jinja2 模板中，articles 始终未定义并被忽略。

class submitPage(Handler): 
    def render_post(self, error="", title="", article="", author=""): 
        articles = db.GqlQuery("SELECT * FROM articleArchive ORDER BY datetime DESC")
        self.render("submit.html",  error=error, title=title, article=article, author=author)

【讨论】：