请求检查所有数组元素

Question

我有一个MongoDB语法问题。
我有两个文档:
alley(the "tree")字段是树的ID):

{
"_id": {"$oid": "62572d82cc40164fef7f1a56"},
"name": "good alley",
"tree": [
{"$oid": "626976eb4b93122bc617d701"},
{"$oid": "626976eb4b93122bc617d702"}
]
},

,
树:

{
"_id": {"$oid": "626976eb4b93122bc617d701"},
"dateInstall": {"$date": "2021-02-27T00:00:00.000Z"},
"species": [
{"$oid": "62585a63edfc726a4ff24fb8"}
]
},

.......

我需要写一个查询"去年没有种树的巷子">
我的代码

db.alley.aggregate([
{
$lookup: {
from: "tree",
localField: "tree",
foreignField: "_id",
as: "tree"
}
},
{
$match: {{$not:{$and:[
{"tree.dateInstall": {$gt: new ISODate("2020-12-31")}},
{"tree.dateInstall": {$lt: new ISODate("2022-01-01")}}
]
}}}
}
]);

Answer 1

您应该首先在小巷中$unwind树，以便您可以正确地$lookup树收集中的树。使用pipeline内部查找只查询去年种植的树木。最后，$group树再次进入小巷，用$match过滤掉没有树的小巷。

db.getCollection("alley").aggregate([
{
$unwind: "$tree",
},
{
$lookup: {
from: "tree",
let: { tree: "$tree" },
pipeline: [
{
$match: {
$expr: {
$and: [
{ $eq: [ "$$tree", "$_id" ] },
{ $gt: [ "$dateInstall", new ISODate("2020-12-31") ] },
{ $lt: [ "$dateInstall", new ISODate("2022-01-01") ] },
]
}
}
}
],
localField: "tree",
foreignField: "_id",
as: "tree"
}
},
{
$group: {
_id: { id: "$_id", name: "$name" },
trees: { $addToSet: { $first: "$tree" } }
}
},
{
$match: {
trees: { $size: 0 }
}
}
])