查询 mongodb 数据库时出现无效文档错误

Question

我在查询我的 mongodb 数据库时遇到此错误：bson.errors.InvalidDocument: 文档必须只有字符串键，键是 函数位置在 0x7f50be59ac80，我的数据库集合看起来像这样（见下图）

这是代码

@app.route('/request books', methods=['GET', 'POST'])
@app.route('/get books', methods=['GET', 'POST'])
def requesting_for_books():
    try:
        mydb = mongo.db.mylogin
        user_col = mydb.find_one({"email" : session['email']})
        final = dict(user_col)
        verify = final['isVerified']
        form = RequestBooks()
        if ('email' in session and verify == True) and ('password' in session and request.method == 'GET'):
            return render_template('get_books.html', title="Get Books", donated_by=session['username'], form=form)
        elif 'email' in session and request.method == 'POST':
            requesting = mongo.db.mylogin   
            request_books = requesting.find({ location: { "$nearSphere": { "$geometry" : {"type" : "Point",  "coordinates": [session['lat'], session['lang']]} } } })

            x = []
            for i in request_books:
            x.append(i)
            real_data = x
            if request_books == None:
                flash("Please enter a search query !")
                return render_template('get_books.html', title='Get Books', form=form)
            else:
                return render_template('get_books.html', title="Get Books", request_books=request_books[0], form=form)
        else:
            flash('Please Login/Sign Up first to Search for books !')
            return redirect(url_for('home'))
    except KeyError:
        flash("Please Sign in first !")
        return render_template('index.html', title="Home")

但是，如果我遍历 request_books 变量，我可以得到 我的文档的 pymongo 光标值。

请帮忙！

Answer 1

查询中的location 应该是一个字符串，用单引号或双引号括起来。 可能你在模块的其他地方（或在其他用form module_name import * 调用的模块中）有一个名为location 的函数。

您可以通过一些编辑使代码更简单/更具可读性：

# since REST APIs have the get and set verb embedded into the HTTP method,
# just use "books" (this is a personal preference, though)
@app.route('/books', methods=['GET', 'POST'])
def requesting_for_books():
    mydb = mongo.db.mylogin
    # it's better to handle exception as soon as they arise,
    # with the added bonus that you don't need to check 
    # if email is in session in the following statements
    try:
        user_col = mydb.find_one({"email" : session['email']})
    except KeyError:
        flash("Please Sign in first !")
        return render_template('index.html', title="Home")
    # user_col is already a dictionary, no need to transform it
    verify = user_col['isVerified']
    form = RequestBooks()
    # if the code runs until here, then email must be in session, no need to check
    # `== True` can be omitted
    if verify and 'password' in session and request.method == 'GET':
        return render_template(
           'get_books.html',
           title="Get Books",
           donated_by=session['username'],
           form=form
        )
    # since you returned in the previous if,
    # there's no need for an else/elif statement, just use if again
    if request.method == 'POST':
        # I suppose this is wrong,
        # it should be point to the books collection and not mylogin collection
        requesting = mongo.db.mylogin
        # if you need only the first element, just use find_one
        request_books = requesting.find_one({
            "location": {
                "$nearSphere": {
                    "$geometry" : {
                        "type" : "Point",
                        "coordinates": [session['lat'], session['lang']]
                    }
                 }
            }
        })
        # you can pass request_books to render_template even if it is None
        # and handle the presence of data directly in the template
        return render_template(
            'get_books.html',
            title="Get Books",
            request_books=request_books,
            form=form
        )
    # no need to use "else", since you returned from the other branches
    flash('Please Login/Sign Up first to Search for books !')
    return redirect(url_for('home'))

如果您想获取所请求书籍的列表，您可以简单地使用查找功能并将光标转换为列表，这样您将获得一个字典列表：

request_books = list(requesting.find({
    "location": {
        "$nearSphere": {
            "$geometry" : {
                "type" : "Point",
                "coordinates": [session['lat'], session['lang']]
            }
        }
    }
}))