在云函数里随机获取数据库的一个记录的某一个字段，但是报错了 代码如下： let word = await db.collection('word') .aggregate() .sample({ size: 1 }) .end() // .then(res => {console.log("随机数结果",res.data[0].eng,res.data[0].chs); }) .then(res => { console.log("随机数结果", res); }) .catch(err => {console.log("随机数错误",err); }) console.log("中文",word.data[0].chs) 返回结果： {"errorCode":1,"errorMessage":"user code exception caught","stackTrace":"Cannot read property 'data' of undefined"} 日志： START RequestId: f2f88334-f188-11e9-aabf-525400697544 Event RequestId: f2f88334-f188-11e9-aabf-525400697544 2019-10-18T09:23:30.696Z f2f88334-f188-11e9-aabf-525400697544 随机数结果 { list: [ { _id: 'XakbZfdsX1oQevCz', chs: '钢笔', eng: 'pen' } ],   errMsg: 'collection.aggregate:ok' } TypeError: Cannot read property 'data' of undefined     at EventHandler.exports.main [as realHandler] (/var/user/index.js:28:27)     at <anonymous>     at process._tickCallback (internal/process/next_tick.js:188:7) END RequestId: f2f88334-f188-11e9-aabf-525400697544 Report RequestId: f2f88334-f188-11e9-aabf-525400697544 Duration:38ms Memory:256MB MaxMemoryUsed:30.636719MB