danared

var updates = { $unset: { steak: true }, $set: { eggs: 0 } };
Breakfast.update({}, updates, callback);

danared

var updates = { $unset: { steak: true }, $set: { eggs: 0 } };
// Note the `runValidators` option
Breakfast.update({}, updates, { runValidators: true }, function(err) {
  console.log(err.errors['steak'].message);
  console.log(err.errors['eggs'].message);
  /*
   * The above error messages output:
   * "Path `steak` is required."
   * "Path `eggs` (0) is less than minimum allowed value (2)."
   */

danared

var updates = { $inc: { eggs: -1 } };
Breakfast.update({}, updates, callback);

danared

var breakfastSchema = new mongoose.Schema({
  steak: {
    type: String,
    required: true,
    enum: ['flank', 'ribeye'],
    validate: function(v) {
      // Woops! `this` is equal to the global object!
      if (this.eggs >= 4) {
        return v === 'flank';
      }

danared

var breakfastSchema = new mongoose.Schema({
  steak: {
    type: String,
    required: true,
    enum: ['flank', 'ribeye'],
  },
  eggs: {
    type: Number,
    required: true,
    min: 2

danared

/*
 * Any schema with this plugin will run validators on
 * `findOneAndUpdate()` by default.
 */
var runValidatorsPlugin = function(schema, options) {
  schema.pre('findOneAndUpdate', function(next) {
    this.options.runValidators = true;
    next();
  });
};

danared

var personSchema = new mongoose.Schema({
  name: String
});

var bandSchema = new mongoose.Schema({
  name: String,
  lead: { type: mongoose.Schema.Types.ObjectId, ref: 'person' }
});

var Person = mongoose.model('person', personSchema, 'people');

danared

Band.
  findOne({ name: "Guns N' Roses" }).
  populate('lead').
  exec(function(err, band) {
    console.log(band.lead.name); // "Axl Rose"
  });

danared

var bandSchema = new mongoose.Schema({
  name: String,
  lead: { type: mongoose.Schema.Types.ObjectId, ref: 'person' }
});

var autoPopulateLead = function(next) {
  this.populate('lead');
  next();
};

danared

Band.
  findOne({ name: "Guns N' Roses" }).
  exec(function(err, band) {
    console.log(band.lead.name); // "Axl Rose"
  });