Mongoose: How to get indexes from model instance

Created on 23 Jun 2015 · 4Comments · Source: Automattic/mongoose

Given a model instance I need to find the indexes defined on it's schema. A model instance has a schema property, which in turn has an _indexes property which contains the information I'm looking for. But I guess the leading underscore marks this property as "private" in the sense of "don't use this property, it's not meant to be accessed directly and can change at any time". Am I right? And if so, what is the correct way to get the indexes from a model instance?

help

Source

skleeschulte

Most helpful comment

Ok this works for me...

router.get('/', function (req, res, next) {

  let models = mongoose.modelNames();

  async.mapLimit(models, 6, function (name, cb) {

    const m = mongoose.model(name);

    m.collection.indexes(function (err, indexes) {

      if (err && err.message === 'no collection') {
        return cb(null, {
          [name]: 'no collection'
        })
      }
      cb(err, {
        [name]: indexes
      })
    });

  }, function (err, results) {

    if (err) {
      return next(err);
    }

    res.json({
      success: results
    })
  })

});

ORESoftware on 18 May 2017

👍2

All 4 comments

Do you need to get the indexes defined on the mongoose schema or the actual indexes defined on the mongodb server? For the latter, Model.collection.indexes(function(error, indexes) {}); should access the underlying driver's method for getting all indexes defined on the collection. If you're looking for the indexes defined on a schema, which in theory is a subset of the indexes defined on the mongodb server as long as mongoose's index build succeeded, var indexes = Model.schema.indexes(); should work

vkarpov15 on 24 Jun 2015

👍2

@vkarpov15 yeah I don't follow.. what is Model.collection? I would be looking to get a representation of the indexes in the database

something like this

https://docs.mongodb.com/v3.0/tutorial/list-indexes/

When I use

let models = mongoose.models;

models.forEach(function(m){
  m.collection...
});

I get this "no collection" error

{
"message": "no collection",
"shortStackTrace": "MongoError: no collection\n    at _combinedTickCallback (internal/process/next_tick.js:73:7)\n    at process._tickCallback (internal/process/next_tick.js:104:9)",
"fullStackTrace": "MongoError: no collection\n    at Function.MongoError.create (/Users/alexamil/WebstormProjects/cisco/cdt-now/node_modules/mongoose/node_modules/mongodb-core/lib/error.js:31:11)\n    at queryCallback (/Users/alexamil/WebstormProjects/cisco/cdt-now/node_modules/mongoose/node_modules/mongodb-core/lib/cursor.js:212:36)\n    at /Users/alexamil/WebstormProjects/cisco/cdt-now/node_modules/mongoose/node_modules/mongodb-core/lib/connection/pool.js:455:18\n    at _combinedTickCallback (internal/process/next_tick.js:73:7)\n    at process._tickCallback (internal/process/next_tick.js:104:9)"
}

pretty weird

ORESoftware on 18 May 2017

Ok this works for me...

router.get('/', function (req, res, next) {

  let models = mongoose.modelNames();

  async.mapLimit(models, 6, function (name, cb) {

    const m = mongoose.model(name);

    m.collection.indexes(function (err, indexes) {

      if (err && err.message === 'no collection') {
        return cb(null, {
          [name]: 'no collection'
        })
      }
      cb(err, {
        [name]: indexes
      })
    });

  }, function (err, results) {

    if (err) {
      return next(err);
    }

    res.json({
      success: results
    })
  })

});

ORESoftware on 18 May 2017

👍2

db.getCollectionNames().forEach(function(collection) {
indexes = db[collection].getIndexes();
print("Indexes for " + collection + ":");
printjson(indexes);
});