在mongo中按ID或用户名查找 [英] Find by id or username in mongo

问题描述

我正在尝试通过用户名或_id进行查找

I'm trying to do a find by username or _id like this

exports.getUser = function (req, res){
    User.find({ $or: [ {username:req.params.id}, {_id:req.params.id} ] })
        .exec(function (err, collections) {
    res.send(collections);
    });
};

当我通过_id搜索但无法输入用户名时，它可以工作，因为它无法返回有效的OjectID.我试过像这样两个独立的查询

It works when I search by _id but fails for username because it fails to return a valid OjectID. I tried doing two separate queries like this

exports.getUser = function (req, res){
    User.findOne({username:req.params.id}).exec(function (err, user) {
        if (user)
            res.send(user);
    });

    User.findById({_id:req.params.id}).exec(function (err, user) {
        if (user)
            res.send(user);
    });
};

，但是如果用户不存在，则挂起，因为它从不发送响应.由于节点是异步的，如果添加

but this hangs if the user doesn't exist because it never sends a response. Since node is async I get Error: Can't set headers after they are sent. if I add

else
    res.sendStatus(400);

到findById查询.我想不出任何其他方法来解决这个问题.我在 MongoDB节点检查objectid是否有效

to the findById query. I can't think of any other way to solve this.I tried the regex in MongoDB Node check if objectid is valid

exports.getUser = function (req, res){
    var checkForHexRegExp = new RegExp("^[0-9a-fA-F]{24}$");
    if(checkForHexRegExp.test(req.params.id)){
        User.findById({_id:req.params.id}).exec(function (err, user) {
            if (user)
                res.send(user);
        });
    }
    User.findOne({username:req.params.id}).exec(function (err, user) {
            res.send(user);
    });

};

我也遇到了同样的错误，因为它是异步的.必须有比这更好的方法

And I'm getting the same error because it's async. There has to be a better way than this

推荐答案

您的第一个查询很可能无法正常工作，因为MongoDB期望_id是ObjectId，而不是字符串(req.params.id可能是字符串) :

Most likely your first query won't work because MongoDB is expecting that _id is an ObjectId, and not a string (which req.params.id probably is):

var ObjectId = require('mongoose').Types.ObjectId;

exports.getUser = function (req, res) {
  var id  = req.params.id;
  var $or = [ { username : id } ];

  // Does it look like an ObjectId? If so, convert it to one and
  // add it to the list of OR operands.
  if (ObjectId.isValid(id)) {
    $or.push({ _id : ObjectId(id) });
  }

  User.find({ $or : $or }).exec(function (err, collections) {
    // TODO: check for errors
    res.send(collections);
  });
};

这篇关于在mongo中按ID或用户名查找的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！