javascript - Mongoose .js : force always populate

Question

有没有办法指示模型总是填充某个字段？

类似于在任何查找查询中填充“字段”:

{field: Schema.ObjectId, ref: 'Ref', populate: true}

?

Answer 1

在 Mongoose 4.0 中，您可以使用查询 Hook 来自动填充您想要的任何内容。

以下示例来自 introduction document瓦莱里·卡尔波夫(Valeri Karpov)。

模式定义:

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');
var Band = mongoose.model('band', bandSchema, 'bands');

var axl = new Person({ name: 'Axl Rose' });
var gnr = new Band({ name: "Guns N' Roses", lead: axl._id });

查询 Hook 以自动填充:

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

bandSchema.
  pre('findOne', autoPopulateLead).
  pre('find', autoPopulateLead);

var Band = mongoose.model('band', bandSchema, 'bands');