原始数据：[{
{
"_id": "8d65afde5e4d2a79010af3ae173f3c31",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "A",
"nameB": "A3",
"nameC": "E3333"
},
{
"_id": "8d65afde5e4d2a79010af3b03f094576",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "A",
"nameB": "A3",
"nameC": "E3333"
},
{
"_id": "fb16f7905e4d2c00010c97000eab34a6",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A5",
"nameC": "E3333"
},
{
"_id": "4278fc3a5e4d2c080109a9095277efc3",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A5",
"nameC": "E222222"
},
{
"_id": "fb16f7905e4d2c0f010c9de51a769a17",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A5",
"nameC": "E11111"
},
{
"_id": "e30d61715e4d2c15010a550712a94455",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A4",
"nameC": "E11111"
},
{
"_id": "7d79e8035e4d2c1b010b25d421d9aabc",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A4",
"nameC": "E222222"
},
{
"_id": "7d79e8035e4d2c23010b29a05652d1ad",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A4",
"nameC": "E3333"
},
{
"_id": "8d65afde5e4d2c2b010bd06b467f35c3",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A3",
"nameC": "E3333"
},
{
"_id": "e30d61715e4d2c30010a62d60a9231b1",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png",
"nameA": "B",
"nameB": "A3",
"nameC": "E2222"
}
]
{
全成后希望变成相同的nameB的image子项并成一个数组，请指教！！！
[
{
"_id": "C",
"child": [
{
"nameB": "A3",
"image": [{
"nameC": "E1111",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png"
}，
{
"nameC": "E22222",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png"
}，
{
"nameC": "E33333",
"imageC": "http://tmp/wx9696d4e5754a92b0.o6zAJs_sYdqkP5OplRpgfPIz-Vis.9cIQCAVc8Pe4a3f590515973ba69b44c5f86b56dff81.png"
}
]
勉强实现 const cloud = require('wx-server-sdk') cloud.init() const db = cloud.database(); const $ = db.command.aggregate exports.main = async(event, context) => { return await db.collection('test').aggregate() .lookup({ from: 'test', localField: 'nameA', foreignField: 'nameA', as: 'bookList', }) .project({ nameA: 1, nameB: 1, bookList: 1 }) .replaceRoot({ newRoot: { nameA: "$nameA", nameB: "$nameB", image: "$bookList" } }) .group({ _id: '$nameA', child: $.addToSet({ nameB: "$nameB", image: $.filter({ input: '$image', as: 'item', cond: $.eq(['$$item.nameB', '$nameB']) }) }) }) .end() }// 云函数入口文件
const cloud = require('wx-server-sdk')
cloud.init()
const db=cloud.database()
const _ = db.command
const $ = db.command.aggregate
// 云函数入口函数
exports.main = async(event, context) => {
const wxContext = cloud.getWXContext()
return new Promise((resolve,reject)=>{
db.collection('category').aggregate()
.lookup({
from: 'category',
localField: 'nameA',
foreignField: 'nameA',
as: 'bookList',
})
.project({
nameA: 1,
nameB: 1,
bookList: 1
})
.replaceRoot({
newRoot: {
nameA: '$nameA',
nameB: '$nameB',
images: '$bookList'
}
})
.group({
_id: '$nameA',
child: $.addToSet({
nameB: '$nameB',
images: $.filter({
input: '$images',
as: 'item',
cond: $.eq(['$$item.nameB', '$nameB'])
})
})
})
.end()
.then((res)=>{resolve(res)})
.catch((err)=>{console.log(err)})
})
}