具有$ or条件的猫鼬的find方法无法正常工作

我通过谷歌搜索解决了这个问题：

var ObjectId = require('mongoose').Types.ObjectId;var objId = new ObjectId( (param.length < 12) ? "123456789012" : param );// You should make string 'param' as ObjectId type. To avoid exception, // the 'param' must consist of more than 12 characters.User.find( { $or:[ {'_id':objId}, {'name':param}, {'nickname':param} ]},   function(err,docs){    if(!err) res.send(docs);});