CODEWITHSUNDEEP
javascriptnode.jsmongodbmongoosemongodb-query
Peter
Peter

Reputation: 1710

Query Callback Not Called When Mongoose Connection Created In Another Function

When I query right after creating and opening mongoose connection as shown below, the query callback is hit and docs are loaded.

var db,
    mongoose = require('mongoose');

...

MyClass.prototype.query = function(model, criteria, callback) {
  var options = {
    server: {
      auto_reconnect: true,
      socketOptions : {
        keepAlive: 1
      }
    }
  };

  mongoose.connect('mongodb://localhost/mydatabase', options);

  db = mongoose.connection;

  db.on('error', console.error.bind(console, 'Error:'));

  db.once('open', function () {
    model.find(criteria).exec(function(err, docs) {
      callback(err, {}, docs);
    });
  });
};

However, when I create the connection in an initDB function and make the query later on as shown below, the callback is not called. initDB is being called before express server is started.

var db,
    mongoose = require('mongoose');

...

function initDB() {
  var options = {
    server: {
      auto_reconnect: true,
      socketOptions : {
        keepAlive: 1
      }
    }
  };

  mongoose.connect('mongodb://localhost/mydatabase', options);

  db = mongoose.connection;

  db.on('error', console.error.bind(console, 'Error:'));
}

...

MyClass.prototype.query = function(model, criteria, callback) {
  db.once('open', function () {
    model.find(criteria).exec(function(err, docs) {
      callback(err, {}, docs);
    });
  });
};

What am I missing here? Any help would be greatly appreciated!

Upvotes: 3

Views: 1678

Answers (1)

Cengiz
Cengiz

Reputation: 1060

This is most probably because the callback passed to db.once('open', ... is being called only once when a connection to your database has been established. Try moving the call to db.once() into your initDB() function as follows:

var db,
    mongoose = require('mongoose');

...

function initDB() {
  var options = {
    server: {
      auto_reconnect: true,
      socketOptions : {
        keepAlive: 1
      }
    }
  };

  mongoose.connect('mongodb://localhost/mydatabase', options);

  db = mongoose.connection;

  db.once('open', function () {
    console.log('Connected to database!');
  });

  db.on('error', console.error.bind(console, 'Error:'));
}

...

MyClass.prototype.query = function(model, criteria, callback) {
  model.find(criteria).exec(function(err, docs) {
    callback(err, {}, docs);
  });
};

Upvotes: 1

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