使用猫鼬模型添加查询条件

Question

using Node.js, Mongoose Schema and MongoDB,

the user model Schema is

    var mongoose = require('mongoose');
    var Schema   = mongoose.Schema;

    var userSchema = new Schema({
        name:             { type: String, trim: true }
      , address:          { type: String }
      , birth:            { type: Date }
      , tlf:              { type: String }
      , email:            { type: String, lowercase: true }
  });

module.exports = mongoose.model('User', userSchema);

and the function to query users with conditions (var cond), select (var sel), options (var opts) is

 findAllUsers = function (req, res, next) {
    var cond = {
      name : req.query.nm

    };
    var sel = 'name address';
    var opts = { 
        skip: req.query.sk, limit: req.query.lim, sort: req.query.srt
    };

    User.find(cond, sel, opts).lean().exec(function (err, users) {
        if (err) next(err);
        var body = {};
        body.skip = req.query.sk;
        body.limit = req.query.lim;
        body.users= users;

        User.count(cond).exec(function (err, total) {
            if (err) next(err);
             body.total = total;
            res.json(body);
          });
      });
  }

and then, what is the best way to create a conditions with regexp, like, or... ?

Answer 1

The equivalent to "like" in MongoDB is the regex operator and would be implemented like this:

db.collection.find({ "address": { "$regex": "via" } });

Keep in mind though, that just the same as the equivalent like "%via%" statement, this does need to scan every document in the collection (or at best index) in order to match the string that is not "anchored" to the start of the string.