我有一个汇总的mongo文档,如下所示。有两个不同的批次(“ -次要”和“ -主要”),每个批次也具有“ batchElements”。
{
"_id" : "123",
"info" : {
"batch" : "Batch1-Minor"
},
"batchElements" : {
"elements" : [
{ }, { }, .... { }
]
}
},
{
"_id" : "123",
"info" : {
"batch" : "Batch2-Minor"
},
"batchElements" : {
"elements" : [
{ }, { }, .... { }
]
}
},
{
"_id" : "123",
"info" : {
"batch" : "Batch3-Major"
},
"batchElements" : {
"elements" : [
{ }, { }, .... { }
]
}
},
{
"_id" : "123",
"info" : {
"batch" : "Batch4-Major"
},
"batchElements" : {
"elements" : [
{ }, { }, .... { }
]
}
}
如何收集“ -次要”和“ -主要”的所有“ batchElements”并创建如下文档;
输出:
{
"_id" : "123",
"minorElements" : [
[{}, {}, {}, ..... {} ], // elements of "Batch1-Minor"
[{}, {}, {}, ..... {} ], // elements of "Batch2-Minor"
... // elements of "BatchN-Minor"
],
"majorElements" : [
[{}, {}, {}, ..... {} ], // elements of "Batch3-Major"
[{}, {}, {}, ..... {} ], // elements of "Batch4-Major"
... // elements of "BatchN-Major"
]
}
答案 0 :(得分:2)
您可以从$split开始,将批次的“类型”作为$group _id
的一部分。然后,您可以运行另一个$group
以使同一文档的minor
和major
组成部分。在最后一步中,您需要$replaceRoot和$arrayToObject一起将两个数组提升为根级别。
db.collection.aggregate([
{
$group: {
_id: {
id: "$_id",
type: { $arrayElemAt: [ { $split: [ { $toLower: "$info.batch" }, "-" ] }, 1 ] }
},
docs: { $push: "$batchElements.elements" }
}
},
{
$group: {
_id: "$_id.id",
data: { $push: { k: { $concat: ["$_id.type","Elements"] }, v: "$docs" } }
}
},
{
$replaceRoot: {
newRoot: {
$mergeObjects: [ { _id: "$_id" }, { $arrayToObject: "$data" } ]
}
}
}
])