避免重复文档和查找相同的"as"键

Question

我正试图让一个聚合与猫鼬一起工作，但我遇到了几个问题，

来自用户模型的文档

{
"_id": {
"$oid": "630273bbe0f3f82d85b149bd"
},
"password": "$2b$12$2f04ijl0fDVHUgBF3rZi.eKfNYkzHZShHNPKfiDEu2NXEXhb.2O",
"name": "name1",
"tel": "[phone]"
}

潜在客户模型文档

{
"_id": {
"$oid": "6319e54c8cc8b7a5521ad266"
},
"name": "name2",
"tel": "[phone]"
}

我有另一个模型Bookings，其中ref是Users或Leads模型，我想与之进行聚合，

有一个预订文件的例子：

{
"_id": {
"$oid": "6310a86c6303d0987fe6fac4"
},
"date": {
"$date": "2022-09-01T14:36:12Z"
},
"user": {
"$oid": "630273bbe0f3f82d85b149bd"
},
"ref": "User"
}

这是我的聚合：

const leads = await this.bookingModel.aggregate([
{
$group: {
_id: {
user: '$user'
}
}
},
{
$lookup: {
from: 'users',
localField: '_id.user',
foreignField: '_id',
as: 'leadUser',
pipeline: [
{
$project: {
name: 1,
tel: 1
}
}
]
}
},
{ $unwind: { path: '$leadUser', preserveNullAndEmptyArrays: true } },
{
$lookup: {
from: 'leads',
localField: '_id.user',
foreignField: '_id',
as: 'lead',
pipeline: [
{
$project: {
name: 1,
tel: 1
}
}
]
}
},
{ $unwind: { path: '$lead', preserveNullAndEmptyArrays: true } }
])

，有几个问题我想解决

首先，我不能在查找as时设置相同的密钥，如何避免放置lead和leadUser并放置相同的密钥

此外，如何通过tel来$group以避免重复文档，tel在两个模型中，现在我只与用户分组，但我不希望用户和Lead有相同的电话。

编辑：有操场https://mongoplayground.net/p/TyYvasdyz_O

我想要铅和铅用户的相同密钥，并按电话分组以删除重复的

非常感谢！

Answer 1

如果我理解正确，你想要这样的东西：

1. 在$lookups之后，不要执行`$unvent，而是连接数组并只保留第一项
2. 按$tel分组以保持其唯一性

db.bookings.aggregate([
{$group: {_id: {user: "$user"}}},
{$lookup: {
from: "users",
localField: "_id.user",
foreignField: "_id",
as: "leadUser",
pipeline: [{$project: {name: 1, tel: 1}}]
}
},
{$lookup: {
from: "leads",
localField: "_id.user",
foreignField: "_id",
as: "lead",
pipeline: [{$project: {name: 1, tel: 1}}]
}
},
{$project: {lead: {$first: {$concatArrays: ["$lead", "$leadUser"]}}}},
{$group: {_id: "$lead.tel", lead: {$first: "$lead"}, user: {$first: "$_id.user"}}},
{$project: {_id: {user: "$user"}, lead: 1}}
])

看看它是如何在操场上工作的例子