如何在Mongodb中拉出嵌套对象? [英] How to Pull Out nested Objects in Mongodb?
本文介绍了如何在Mongodb中拉出嵌套对象?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我正在尝试通过合并另一个集合进行查询，但是运行查询时会遇到障碍，生成的数据不是我想像的
I'm trying to make a query by merging from another collection, but there are obstacles when the query is run, the data generated is not what I imagined
我有这样的数据
{
"_id": "5ce8981a46039c14a4ec32d1",
"name": "Monkey D Luffy",
"email": "aaa@aaa.com",
"status": "not verified",
"password": "$2a$10$ayluBIsOOelBTIk.69GjHubgQemr6dJfgBUELNusCOaUGLpS/qKs6",
"metas": {
"role": "admin",
"smartphone": "ios",
"address": "konoha",
"hobby": "eat ramen"
}
},
我想从嵌套文档中提取元数据:
and i want pull out metas from nested document :
{
"_id": "5ce8981a46039c14a4ec32d1",
"name": "Monkey D Luffy",
"email": "aaa@aaa.com",
"status": "not verified",
"password": "$2a$10$ayluBIsOOelBTIk.69GjHubgQemr6dJfgBUELNusCOaUGLpS/qKs6",
"role": "admin",
"smartphone": "ios",
"address": "konoha",
"hobby": "eat ramen"
},
如果我的问题中有任何重复之处提示我，因为我没有找到相同的问题，主要是使用数组.
if any duplicate from my question pls suggest me, because I didn't find the same question, mostly using arrays.
这是我的查询:
db.accounts.aggregate([
{
$lookup: {
from: "account_meta",
localField: "_id",
foreignField: "account_id",
as: "metas"
}
},
{ "$unwind": "$metas" },
{
$group: {
_id: "$_id",
name: {$first:"$name"},
status: {$first: "$status"},
email: {$first: "$email"},
password: {$first: "$password"},
data: {
"$push": {
"k" : "$metas.key",
"v": "$metas.value"
}
}
}
},
{
$project: {
"_id": "$_id",
"name": "$name",
"email": "$email",
"status": "$status",
"password": "$password",
"metas" :{
$arrayToObject: "$data"
}
}
},
{
"$replaceRoot": {
"newRoot":
{
"$mergeObjects": [ {$arrayToObject: "$data"}, "$$ROOT"]
},
}
},
])
推荐答案
我只是从$ mergeObject编辑一些代码:
i just edit some code from my $mergeObject:
{
"$replaceRoot": {
"newRoot":
{
"$mergeObjects": [ "$metas", "$$ROOT"]
},
}
},
{$project: { metas: 0} }
这篇关于如何在Mongodb中拉出嵌套对象?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
