如何在我的网站上显示存储在 db 中的评论？

Question

我想为我的页面创建评论部分，但不是为特定帖子显示 cmets，而是为所有帖子显示 cmets。假设是否有任何用户评论了特定帖子，所以我只希望该帖子的 cmets。我得到的是所有帖子的cmets。让我给你看代码

schema.sql

CREATE TABLE user(
id INTEGER PRIMARY KEY AUTOINCREMENT,
 username TEXT UNIQUE NOT NULL,
 email TEXT UNIQUE NOT NULL,
 password TEXT NOT NULL
);

CREATE TABLE post(
 id INTEGER PRIMARY KEY AUTOINCREMENT,
 author_id INTEGER NOT NULL,
 created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
 title TEXT NOT NULL,
 body TEXT NOT NULL,
 FOREIGN KEY (author_id) REFERENCES user (id)
);

CREATE TABLE comment(
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    user_name TEXT UNIQUE NOT NULL,
    comment TEXT NOT NULL,
    FOREIGN KEY (user_name) REFERENCES user (username)
);

blog.py

from flask import(
Blueprint,url_for,render_template,flash,g,redirect,request)
from werkzeug.exceptions import abort

from flaskr.auth import login_required
from flaskr.db import get_db

bp=Blueprint('blog', __name__)

@bp.route('/')
def index():
    db=get_db()
    posts=db.execute(
        'SELECT p.id, title, body, created, author_id, username'
        ' FROM post p JOIN user u ON p.author_id = u.id'
        ' ORDER BY created DESC'
    ).fetchall()
    comments=db.execute(
        'SELECT c.id, comment, created, user_name'
        ' FROM comment c JOIN user u ON c.user_name = u.username'
        ' ORDER BY created ASC'
    ).fetchall()
    return render_template('blog/index.html', posts=posts,comments=comments)

@bp.route('/create', methods=('GET', 'POST'))
@login_required
def create():
    if request.method=='POST':
        title=request.form['title']
        body=request.form['body']
        error=None

        if not title:
            error='Title is required'

        if error is not None:
            flash(error)
        else:
            db=get_db()
            db.execute(
                'INSERT INTO post (title,body,author_id)'
                'VALUES (?,?,?)',
                (title,body,g.user['id']),
            )
            db.commit()
            return redirect(url_for('blog.index'))
    return render_template('blog/create.html')

def get_post(id, check_author=True):
    post=get_db().execute(
        'SELECT p.id, title, body, created, author_id, username'
        ' FROM post p JOIN user u ON p.author_id = u.id'
        ' WHERE p.id = ?',
        (id,),
    ).fetchone()

    if post is None:
        abort(404, f"Post id {id} doesn't exist.")

    if check_author and post['author_id'] != g.user['id']:
        abort(403)

    return post

@bp.route('/<int:id>/update', methods=('GET', 'POST'))
@login_required
def update(id):
    post=get_post(id)
    if request.method=='POST':
        title=request.form['title']
        body=request.form['body']
        error=None

        if not title:
            error='Title is required'

        if error is not None:
            flash(error)
        else:
            db=get_db()
            db.execute(
                'UPDATE post SET title = ?, body = ?'
                ' WHERE id=?',
                (title,body,id),
            )
            db.commit()
            return redirect(url_for('blog.index'))
    return render_template('blog/update.html', post=post)

@bp.route('/<int:id>/delete', methods=('POST',))
@login_required
def delete(id):
    get_post(id)
    db=get_db()
    db.execute('DELETE FROM post WHERE id=?',(id,))
    db.commit()
    return redirect(url_for('blog.index'))

@bp.route('/<int:id>/comment', methods=('GET','POST'))
@login_required
def comment(id):
    post=get_post(id)
    if request.method=='POST':
        comment=request.form['comment']
        error=None

        if not comment:
            error='Please type comment and try again.'

        if error is not None:
            flash(error)
        else:
            db=get_db()
            db.execute(
                'INSERT INTO comment (comment,user_name)'
                'VALUES (?,?)',
                (comment,g.user['username'],),
            )
            db.commit()
            return redirect(url_for('blog.index'))
    return render_template('blog/comment.html')

index.html

{% extends 'base.html' %}

{% block header %}
    <h1>{% block title %}Posts{% endblock %}</h1>
    {% if g.user %}
        <a class="action" href="{{url_for('blog.create')}}">New</a>
    {% endif %}
{% endblock %}

{% block content %}
    {% for post in posts %}
        <article class="post">
            <header>
                <div>
                    <h1>{{ post['title'] }}</h1>
                    <div class="about">by {{ post['username'] }} on {{ post['created'].strftime('%Y-%m-%d') }}</div>
                </div>
                {% if g.user['id']==post['author_id'] %}
                    <a class="action" href="{{url_for('blog.update', id=post['id'])}}">Edit</a>
                {% endif %}
                {% if g.user %}
                    <a class="action" href="{{url_for('blog.comment', id=post['id'])}}">Comment</a>
                {% endif %}
            </header>
            <p class="body">{{ post['body'] }}</p>
            {% for comment in comments %}
                <ul class="comments">
                    <li><span>{{comment['user_name']}}</span> {{comment['comment']}}</li>
                </ul>  
            {% endfor %}
        </article>
        {% if not loop.last %}
            <hr>
        {% endif %}
    {% endfor %}
{% endblock %}

Answer 1

cmets 表结构似乎不正确。

评论表应该有 post_id 作为外键 id，这将表示该特定评论属于列中提到该 id 的特定帖子。

你需要在这里做三件事：

1. 更改 cmets 表并在此处添加 post_id 作为外键。

CREATE TABLE comment(
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    created TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
    user_name TEXT UNIQUE NOT NULL,
    comment TEXT NOT NULL,
    FOREIGN KEY (user_name) REFERENCES user (username)
    FOREIGN KEY (post_id) REFERENCES post (post_id)
);

1. 每当用户 cmets 发送该特定帖子的 post_id 并将 post_id 填充到 cmets 表中。

2. 更改您的检索查询，您可以在其中获取特定于帖子和用户的 cmets。

如果您这样做正确，那么这应该很容易完成。 在这里看不到任何拦截器。