const cloud = require'wx-server-sdk')
cloud.init({
env: cloud.DYNAMIC_CURRENT_ENV
})
const db = cloud.database()
const _ = db.command
const $ = db.command.aggregate
// 云函数入口函数
exports.main = async (event, context) => {
省略....
const res = await db.collection('orders')
.aggregate()
.addFields(fields)
.match(conditions)
.lookup({
from: 'users',
let: {
_openid: '$_openid'
},
pipeline: $.pipeline()
.match(_.expr($.eq(['$_openid', '$$_openid'])))
.project({
_id: 0,
staffNickName: 1,
nickName: 1
})
.done(),
as: 'userList'
})
.sort({
addTime: -1
})
.skip(skip)
.limit(100)
.addFields({
addTimeS: $.dateToString({
date: '$addTime',
format: '%Y-%m-%d %H:%M:%S',
timezone: 'Asia/Shanghai'
})
})
.end()
详细错误日志如下：
START RequestId: a03972e1-311-11ea-a6f9-525400235f2a
Event RequestId: a03972e1-311-11ea-a6f9-525400235f2a
TypeError: $.pipeline is not a function
at EventHandler.exports.main [as realHandler] (/var/user/index.js:11719)
at EventHandler.handle (/var/runtime/node8/bootstrap.js:40528)
at invoke (/var/runtime/node8/bootstrap.js:20822)
at Timeout.setTimeout [as _onTimeout] (/var/runtime/node8/bootstrap.js:137)
at ontimeout (timers.js:47511)
at tryOnTimeout (timers.js:310)
at Timer.listOnTimeout (timers.js:270)
END RequestId: a03972e1-311-11ea-a6f9-525400235f2a
Report RequestId: a03972e1-311-11ea-a6f9-525400235f2a Duration:ms Memory:256MB MaxMemoryUsed:34.148438MB
如标题提示错误，大家遇到过吗？我目的是让子查询输出字段少一些。如果绕开pipeline，还可以用什么办法？
先试试简单的lookup有没有报错
await db.collection('orders').aggregate() .lookup({ from: 'users', let: { _openid: '$_openid' }, pipeline: $.pipeline() .match(_.expr($.eq(['$_openid', '$$_openid']))) .project({ _id: , staffNickName: , nickName: }) .done(), as: 'userList' }) .end()const $ = db.command.aggregate另外我发现一个小问题：
let: { _openid: '$_openid' }这里的参数里面不能带下划线_，会报错，去掉_可以。