英文:
Identify records in a.d that do not have corresponding record in a.p in nested array
问题
I can provide a translation of the requested text without any additional content. Here is the translated text:
请帮助，我需要识别在a.p[]中没有重复的a.d[]数组记录的列表。在下面的示例中，具有a.d.prid："2"的嵌套对象就是这样一条记录：它与a.p[pid]和a.d[pid]具有相同的pid，但prid不同="2"
示例文档：
{
"f": 1,
"a": [
{
"aid": 1,
"p": [
{
"prid": "1",
"pid": {
"c": "A",
"s": "B",
"k": "C"
},
"X": 20
}
],
"d": [
{
"prid": "1",
"pid": {
"c": "A",
"s": "B",
"k": "C"
}
},
{
"prid": "2",
"pid": {
"c": "A",
"s": "B",
"k": "C"
}
}
]
}
]
}
我需要一个包含所有这样的a.d记录的列表，这些记录在a.d[]和a.p[]中具有相同的pid，但具有不同的prid。
期望的输出：
{ "f": 1, "aid": 1, "prid": 2 }
稍后我需要删除这些嵌套对象，因为它们被视为"损坏的"，但首先需要获取列表...
英文:
Please, help , I need to identify the list of array records a.d[] that do not have duplicate in a.p[] . in the example below nested object with a.d.prid:"2" is such an record:
it has same pid with a.p[pid] and a.d[pid] , but has the prid different="2"
Example document:
{
"f": 1,
a: [
{
aid:1,
p: [
{
prid: "1",
pid: {
c: "A",
s: "B",
k: "C"
},
X: 20
}
],
d: [
{
prid: "1",
pid: {
c: "A",
s: "B",
k: "C"
}
},
{
prid: "2",
pid: {
c: "A",
s: "B",
k: "C"
}
}
]
}
]
}
I need a list with all such a.d records that have pid for same document in a.d[] and a.p[] , but have different prid
Expected output:
{ "f":1 , "aid": 1 , "prid": 2 }
Later I need to delete those nested objects as they are considered "corrupted" , but need to get the list first ...
答案1
得分: 1
以下是您要翻译的内容：
一种选择是在$map内使用$mergeObjects和$in来查找d上没有与p匹配的项目：
db.collection.aggregate([
{$set: {
a: {$map: {
input: "$a",
as: "item",
in: {
d: "$$item.d",
aid: "$$item.aid",
p: {$map: {
input: "$$item.p",
in: {$mergeObjects: [{prid: "$$this.prid"}, "$$this.pid"]}
}}
}}}
}},
{$project: {
_id: 0,
res: {$map: {
input: "$a",
as: "item",
in: {$reduce: {
input: "$$item.d",
initialValue: [],
in: {$concatArrays: [
"$$value",
{$cond: [
{$in: [
{$mergeObjects: [
{prid: "$$this.prid"},
"$$this.pid"
]},
"$$item.p"
]},
[],
[{
f: "$f",
aid: "$$item.aid",
prid: "$$this.prid"
}]
]}
]}
}}
}}
}},
{$set: {
res: {$reduce: {
input: "$res",
initialValue: [],
in: {$concatArrays: ["$$value", "$$this"]}
}}
}},
{$match: {"res.0": {$exists: 1}}}
])
更新： 由于某种原因，它在mongodb playground上不一致，但我不明白为什么。经过测试，在Robo 3T和Studio 3T上是一致的...
英文:
One option is to use $mergeObjects and $in inside a $map to find the items on d without a matching item on p:
db.collection.aggregate([
{$set: {
a: {$map: {
input: "$a",
as: "item",
in: {
d: "$$item.d",
aid: "$$item.aid",
p: {$map: {
input: "$$item.p",
in: {$mergeObjects: [{prid: "$$this.prid"}, "$$this.pid"]}
}}
}}}
}},
{$project: {
_id: 0,
res: {$map: {
input: "$a",
as: "item",
in: {$reduce: {
input: "$$item.d",
initialValue: [],
in: {$concatArrays: [
"$$value",
{$cond: [
{$in: [
{$mergeObjects: [
{prid: "$$this.prid"},
"$$this.pid"
]},
"$$item.p"
]},
[],
[{
f: "$f",
aid: "$$item.aid",
prid: "$$this.prid"
}]
]}
]}
}}
}}
}},
{$set: {
res: {$reduce: {
input: "$res",
initialValue: [],
in: {$concatArrays: ["$$value", "$$this"]}
}}
}},
{$match: {"res.0": {$exists: 1}}}
])
Update: For some reason it is not consistent on the mongodb playground, but I don't understand why. It is tested and consistent on Robo 3T and studio 3T...
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