Question

队

我是mongodb的Spring数据新手。我正在尝试学习用于聚合查询的Spring数据代码。但是大多数教程只显示了简单的例子。您能请帮我构建给定复杂聚合示例的spring数据代码。

SCHEMA:
{
    "s"  : "CB",
    "c"  : "REQ_RCV",
    "e"  : "cta_sms_click",
    "st" : "i",
    "b"  : "UB",
    "a"  : "account-1",
    "u"  : "b1_h1_d1_m1_user_2",
    "c#" : "b1_h1_d1_m1_cr-2",
    "@"  : ISODate("2016-10-01T06:03:00.000Z"),
    "@h" : "16100106",
    "@d" : "161001",
    "@m" : "1610"
}


QUERY:
db.COLLECTION_NAME.aggregate([                       
        {$match:{"st":"i","@":{$gte : new ISODate("2015-10-01T06:00:00Z"), $lte : new ISODate("2017-10-02T10:00:00Z")}, "c":"REQ_RCV"}}, 
        {$group:{_id:{"b":"$b", "HOURLY":"$@h"}, count:{$sum:1}}}, 
        {$project : {_id:0, "BUCKET":"$_id.b", "TIME":"$_id.HOURLY", count:1}},
        {$sort:{"BUCKET":1, "TIME":1}}                     
    ]);

复杂性：

$ match has muliple criterias
$ project必须访问_id
结果无法映射到类，因为它根据$ project字段更改而有所不同。最终我会喜欢将它映射到java.util.HashMap，以便我可以放任何字段在$ project里面。那可能吗？

Veeram的初步答复供参考：

Aggregation agg = newAggregation(match(where("st").is("i").and("@").gte(start_date).lte(end_date).and("c").is("REQ_RCV")),
                    group(fields("b").and("HOURLY", "$@h")).count().as("count"),
                    project(fields("count").and("BUCKET","$_id.b").and("TIME", "$_id.HOURLY")),
                    sort(ASC, "BUCKET", "TIME"));

Answer 1

所以可能有更多的弹簧数据方式来做这个，但我正在做的是连接MongoTemplate并将其用于Aggreagation查询。我的例子比你想做的更简单，但也许它可以帮助：

    @Service
     public class AClass implements CategoryStructureService {

            @Autowired
            private MongoTemplate mongoTemplate ;

    ......
    private int method(CategoryStructureKey csKey) {

            Aggregation agg = Aggregation.newAggregation(Aggregation.match(Criteria
                    .where("_id").is(csKey)), Aggregation.unwind("fields"),
                    Aggregation.project("fields").andExclude("_id"), Aggregation
                            .sort(Direction.DESC, "fields.index"), Aggregation
                            .limit(1));

AggregationResults<MultiValuedFieldContainer> field = mongoTemplate
                .aggregate(agg, CategoryStructure.class,
                        MultiValuedFieldContainer.class);
        ....

        }

我使用旧的spring-boot项目做了这个，将其作为依赖

<dependency>
            <groupId>org.springframework.data</groupId>
            <artifactId>spring-data-mongodb</artifactId>
            <version>1.4.2.RELEASE</version>
        </dependency>

所以它应该有用。

你可以在这里找到一个更好的MongoTemplate示例 https://www.mkyong.com/mongodb/spring-data-mongodb-aggregation-grouping-example/

以及其他一些Agrregation示例 https://github.com/spring-projects/spring-data-mongodb/blob/master/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/aggregation/AggregationTests.java

希望这有帮助

Answer 2

您可以尝试以下内容。替换为您的日期值和集合名称。

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Spring Data Aggregate Query

2 个答案: