绑定参数1时出错：不支持类型'tuple'

Question

我在更新博客文章时遇到问题：

@app.route('/edit_post/<post_id>', methods=['GET', 'POST'])
def edit_post(post_id):
    post = db.get_or_404(BlogPost, post_id)
    edit_form = BlogPostForm(
        title=post.title,
        subtitle=post.subtitle,
        img_url=post.img_url,
        author_name=post.author,
        blog_content=post.body
    )
    if edit_form.validate_on_submit():
        post.subtitle = edit_form.subtitle.data,
        post.img_url = edit_form.img_url.data,
        post.author = edit_form.author_name.data,
        post.body = edit_form.blog_content.data,
        db.session.commit()
        return redirect(url_for("show_post", post_id=post_id))
    return render_template("make-post.html", is_edit=True, form=edit_form)

错误：

sqlalchemy.exc.ProgrammingError: (sqlite3.ProgrammingError) Error binding parameter 1: type 'tuple' is not supported
[SQL: UPDATE blog_post SET subtitle=?, body=?, author=?, img_url=? WHERE blog_post.id = ?]
[parameters: (('Lego is awsome',),....
(Background on this error at: https://sqlalche.me/e/20/f405)

为什么？

Answer 1

在您的更新文件中，删除逗号，例如

post.img_url = edit_form.img_url.data;

以下代码

... post.subtitle = edit_form.subtitle.data

post.img_url = edit_form.img_url.data

post.author = edit_form.author_name.data

post.body = edit_form.blog_content.data 和 db.session.commit()

...