小编ras*_*862的帖子

考虑以下帖子集合：

{
    _id: 1,
    title: "Title1",
    category: "Category1",
    comments: [
                {
                    title: "CommentTitle1",
                    likes: 3
                },
                {
                    title: "CommentTitle2",
                    likes: 4
                }

            ]
}
{
    _id: 2,
    title: "Title2",
    category: "Category2",
    comments: [
                {
                    title: "CommentTitle3",
                    likes: 1
                },
                {
                    title: "CommentTitle4",
                    likes: 4
                }

            ]

}
{
    _id: 3,
    title: "Title3",
    category: "Category2",
    comments: [
                {
                    title: "CommentTitle5",
                    likes: 1
                },
                {
                    title: "CommentTitle6",
                    likes: 3
                }
        ]
    }

我想检索所有帖子，如果一篇帖子有 4 个赞的评论，我只想在“comments”数组下检索此评论。如果我这样做：

db.posts.find({}, {comments: { $elemMatch: {likes: 4}}})

...我明白了（这正是我想要的）： …

我正在通过POST方法验证表单.我想在已注册电子邮件地址时将错误输入express-validator,因此当我执行req.validationErrors()时,它会被包括在内.像这样的东西:

req.checkBody('inputFirstName', 'First name empty').notEmpty();
req.checkBody('inputLastName', 'Last name empty').notEmpty();
db.User.find({email: req.body.inputEmail}, function (err, user){
        if(user){
            var error = {param: "inputEmail", msg: "Email address already registered", value: ''};
            expressValidator._errors.push(error);
        }
    });

谢谢.