mongoose/mongodb query multiple sort

Question

i'm quite new to mongodb. i manage to get a basic idea of a simple sort based only 1 parameter. what if there are more than 2 sort parameters. for instance, in a database made up of woodworking projects that have attributes totalCuttingTime and favorited.

Is the following a correct mongoose/mongodb function to find a list of projects that have the least totalCuttingTime and order in according to highest favoriteCounts to lowest.

var ProjectModel= mongoose.model('Project', schema);

exports.getMinCuttingTime = function(number, callback){      var leastCutTimeResult = ProjectModel.find().sort({totalCuttingTime: 1}).select({_id: 1}).limit(number).exec(             function(err, projects) {                 callback(null, projects)             }         );      var result = leastCutTimeResult.find().sort({favoriteCount: -1}).select({_id: 1}).limit(number).exec(             function(err, projects) {                 callback(null, projects)             }         );       return result; } 

Answer 1

You need to put both sort terms into one object:

exports.getMinCuttingTime = function(number, callback){      ProjectModel.find()         .sort({totalCuttingTime: 1, favoriteCount: -1})         .select({_id: 1})         .limit(number)         .exec(             function(err, projects) {                 callback(null, projects)             }         ); }; 

It's worth noting that the ECMA-262 standard on which Node.js is based doesn't specify that an object's property order is maintained, and it's only a de facto standard to match insertion order. To eliminate any doubt, you can use an array instead:

.sort([['totalCuttingTime', 1], ['favoriteCount', -1]])