dataSource.discoverModelDefinitions返回一个空数组

Question

我正在尝试从MySQL数据库获取表列表，并且代码在下面

./ server / datasources.json

{
  "db": {
    "host": "localhost",
    "port": 3306,
    "database": "xman",
    "password": "toor",    
    "user": "root",
    "connector": "mysql",
    "supportBigNumbers":"true"
  }
}

./ discover-table.js

'use strict';

const loopback = require('loopback');

const DATASOURCE_NAME = 'db';
const dataSourceConfig = require('./server/datasources.json');
const db = loopback.DataSource('mysql', dataSourceConfig[DATASOURCE_NAME]);

db.discoverModelDefinitions(function(err, models) {
  console.log("Data " + models);
  db.disconnect();
});

执行上述文件时，输出为

Data

，并且models变量包含一个空数组。如何获取数据库表列表？

注意：我正在使用环回3.x