mongoose实现id自增

IncrementId

var mongoose = require('mongoose');

var Sequence = require('./sequence');

var pieceSchema = mongoose.Schema({

    id: { type : Number, index: { unique: true } },
    content: String,
    link: String,
    pics:[String] ,
    author: mongoose.Schema.ObjectId ,
    work: Boolean,
    updated: { type: Date, default: Date.now },
    created: { type: Date, default: Date.now }
    
})

//在创建文档时，获取自增ID值
pieceSchema.pre('save', function(next) {
    var self = this;
    if( self.isNew ) {
        Sequence.increment('Piece',function (err, result) {
            if (err)
              throw err;
            self.id = result.next;
            next();
        });
    } else {
        next();
  }
})

var Piece = mongoose.model('Piece', pieceSchema);

module.exports = Piece

sequence

var mongoose = require('mongoose');

var Schema = mongoose.Schema;
var models = {};
/**
  * 存储ID的序列值
  */
SequenceSchema = new Schema({
    _id: String,
    next: Number 
});

SequenceSchema.statics.findAndModify = function (query, sort, doc, options, callback) {
    return this.collection.findAndModify(query, sort, doc, options, callback);
};

SequenceSchema.statics.increment = function (schemaName, callback) {
    return this.collection.findAndModify({ _id: schemaName }, [], 
            { $inc: { next: 1 } }, {"new":true, upsert:true}, callback);
};

var Sequence = mongoose.model('Sequence', SequenceSchema);

module.exports = Sequence

Hi, This code is incorrect，probably is “self.id = result.value.next;”

self.id = result.value.next

it work fine