在Spring Data mongoDb中使用嵌套字段的组操作进行聚合查询

Question

我想创建一个使用spring数据mongodb的聚合查询

我的集合数据结构是:

{
date: ISODate("2022-12-11T01:13:00.000Z"),
metadata: {
homeId: '51b87ea3d846f450141ae58z',
nodeId: '51b87ea3d846f450141ae58z'
},
value: 42,
_id: ObjectId("63b583e30c1e523313b64ed5")
}

MongoDb查询，我想翻译到java是:

db.consumptions.aggregate(
[
{ $match : {"metadata.nodeId": "51b87ea3d846f450141ae58z"}
},
{ $project: { 
date: { 
$dateToParts: { date: "$date"}
}, 
value: 1
}
},
{ $group: { 
_id: { 
date: { 
year: "$date.year", month: "$date.month", day: "$date.day"
}
}, 
cumulValue: { $sum: "$value"}
}
},
{ $sort : { "_id.date": -1}
}
]
)

MongoDb的查询结果如下所示:

[
{
_id: { 
date: { year: 2022, month: 12, day: 11 } 
},
cumulValue: 42 
}
]

如你所见，结果结构是_id嵌套对象date包含年、月和日字段。

我想有相同的结果_id结构使用groupOperation与春季数据mongo。

我试过这个实现

MatchOperation matchOperation = Aggregation.match(
new Criteria().andOperator(Criteria.where("metadata.nodeId").is(nodeId);

// projection Operation
ProjectionOperation projectionOperation = project("value")
.and(DateOperators.dateOf("date").toParts()).as("date");
// group Operation
GroupOperation groupOperation = Aggregation.group(
"date.year", "date.month", "date.day")
.sum("value").as("cumulativeValue");

// Sort Operation
SortOperation sortOperation = sort(pageRequest.getSort());
Aggregation aggregation = Aggregation.newAggregation(
matchOperation, projectionOperation, groupOperation,sortOperation);

但是我不能有预期的结果结构(嵌套对象日期)

{
_id: {
year: 2022,
month: 11,
day: 11
},
cumulValue: 284
}

Answer 1

您可以通过解析整个管道字符串来尝试。

String groupStage = "{rn" + 
"    $group: {rn" + 
"      _id: {rn" + 
"        date: {rn" + 
"          year: "$date.year",rn" + 
"          month: "$date.month",rn" + 
"          day: "$date.day"rn" + 
"        }rn" + 
"      },rn" + 
"      cumulValue: {rn" + 
"        $sum: "$value"rn" + 
"      }rn" + 
"    }rn" + 
"  }"
GroupOperation groupOperation = context -> context.getMappedObject(Document.parse(groupStage));