Dot*_*arp 5 mongodb mongodb-query aggregation-framework
我认为这可能与这个问题有点类似：如何在嵌入式数组文档中使用图形查找聚合，但始终没有答案，我也没有发表评论以查看作者是否找到解决方案的声誉。
尽管该集合将包含成千上万的文档，但是在查询时我只会被其中的1个约束。当前的目的是使用一个初始$match阶段，该阶段将产生一个文档。
样本文件
{
attrA: 'foo',
attrB: 'bar',
versions: [
{
status: "live",
things: [
{
key: "thing_1",
parent: null
slug: "thing-1-slug"
},
{
key: "thing_2",
parent: "thing-1-slug",
slug: "thing-2-slug"
},
{
key: "thing_3",
parent: "thing-2-slug",
slug: "thing-3-slug"
},
{
key: "thing_4",
parent: null,
slug: "thing-4-slug"
},
{
key: "thing_5",
parent: "thing-2-slug",
slug: "thing-5-slug"
},
{
key: "thing_6",
parent: "thing-4-slug",
slug: "thing-6-slug"
},
{
key: "thing_7",
parent: null,
slug: "thing-7-slug"
}
]
},
{
status: "draft"
things: [] // same structure and content of things above
}
]
}
注意事项：
我已经尝试过各种聚合查询，但运气还不足。很乐意张贴其中的一些内容（如果有帮助的话），但没有一个接近预期的结果。
我只在查询时关心集合中的单个文档（目的是$match作为第一阶段）
目前，我无法控制原始属性或文档结构。
我真的想这样做，而不不必使用之类的东西$project，因为我不知道所有的原始文档的属性提前（attrA和attrB示例）。我的想法是，可以通过类似的运营商来做到这一点，$addField但我不确定所有阶段的模样如何。
我只关心versions具有的数组元素status === "live"。如果有一种覆盖方法，versions在查询结果中仅包含“实时”元素，那就更好了。
key特定“事物”元素的属性将是一个已知值（基于HTTP请求有效负载），并且应该/可以用作关系/层次结构事物的“起点”。
parent每个事物元素的属性要么指向另一个事物数组元素的slug属性，要么为null
多个things元素可能具有相同的parent
潜在深度没有限制
预期成果：
知道我想“开始”在thing与，例如key === "thing_3"，我怎么可以创建一个查询，将重新映射/过滤器things是“事元素”是一个数组：
things数组中代表项目的层次结构/关系的所有元素，其中key === "thing_3" versions数组限制为具有status === "live"并已things根据＃1重写其数组的单个元素所需查询结果的示例：
请注意，没有things元素带有keything_4，thing_6和thing_7，因为它们与things从以下位置开始的元素没有父级/关联性key === "thing_3"
如果它简化了操作，则具有key === "thing_5"（也具有parent === "thing-2-slug"）的元素可以包含在结果中，但理想情况下不包括在内。
{
attrA: 'foo',
attrB: 'bar',
versions: [
{
things: [
{
key: "thing_1",
parent: null
slug: "thing-1-slug"
},
{
key: "thing_2",
parent: "thing-1-slug",
slug: "thing-2-slug"
},
{
key: "thing_3",
parent: "thing-2-slug",
slug: "thing-3-slug"
}
]
}
]
}
添加这么多阶段后，我发现了结果，尽管它的格式不合适，因此您可以自定义或也可以优化：
db.collection.aggregate([
{
$unwind: "$versions"
},
{
$project: {
_id:1,
attrA:1,
attrB:1,
versions: {
$filter: {
input: "$versions.things",
as: "th",
cond: {
$or: [
{ $ne: [ "$$th.parent", null ] },
{
$and: [
{ $eq: [ "$$th.parent", null ] },
{ $eq: [ "$$th.key", "thing_1" ] }
]
}
]
}
}
}
}
},
{
$unwind: "$versions"
},
{
$graphLookup: {
from: "slug",
startWith: "$versions.slug",
connectFromField: "versions.slug",
connectToField: "versions.things.parent",
as: "reportingHierarchy"
}
},
{
$match: {
$expr: { $ne: [ {$size: "$reportingHierarchy" },0 ] }
}
},
{
$group: {
_id: null,
parents: { $addToSet: "$versions.slug" },
data: { $push: "$$ROOT"}
}
},
{
$unwind: "$data"
},
{
$addFields: {
newVersions:
{
$map:
{
input: "$data.reportingHierarchy",
as: "hierarchy",
in: {
"columns": {
$map:
{
input: "$$hierarchy.versions",
as: "version",
in: {
"$filter": {
"input": "$$version.things",
"as": "th",
"cond": {
$or: [
{ $setIsSubset: [ ["$$th.parent"], "$parents" ] },
{ $eq: [ "$$th.key", 'thing_1']}
]
}
}
}
}
}
}
}
}
}
},
{
$project: {
newVersions:1
}
}
])
该查询的结果响应如下：
/* 1 */
{
"_id" : null,
"newVersions" : [
{
"columns" : [
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
],
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
]
]
}
]
},
/* 2 */
{
"_id" : null,
"newVersions" : [
{
"columns" : [
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
],
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
]
]
}
]
},
/* 3 */
{
"_id" : null,
"newVersions" : [
{
"columns" : [
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
],
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
]
]
}
]
},
/* 4 */
{
"_id" : null,
"newVersions" : [
{
"columns" : [
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
],
[
{
"key" : "thing_1",
"parent" : null,
"slug" : "thing-1-slug"
},
{
"key" : "thing_2",
"parent" : "thing-1-slug",
"slug" : "thing-2-slug"
},
{
"key" : "thing_3",
"parent" : "thing-2-slug",
"slug" : "thing-3-slug"
},
{
"key" : "thing_5",
"parent" : "thing-2-slug",
"slug" : "thing-5-slug"
}
]
]
}
]
}
结果是逆风，因此有多个条目，但您可以自定义它。
注意：根据“thing_1”的值，您将根据您的要求获得层次结构数据。
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