MongoDB聚合查询的Spring数据

debugcn 发表于 Dev

燃料油

我正在努力在Spring Data MongoDB中翻译此mongoDB查询：

db.applicates.aggregate(
   [
   {
      "$match": {
        "claimantCategory": 1
      }
    },
      {
        $group : {
           _id : { month: { $month: "$claimDate" }, day: { $dayOfMonth: "$claimDate" }, year: { $year: "$claimDate" } },
       count: { $sum: 1 }
    }
  }
   ]
)

我已经尝试过了：

TypedAggregation<Applicate> aggregation = newAggregation(Applicate.class,
            match(Criteria.where("claimantCategory").is(claimantCategory)),
            project("claimDate")
                    .andExpression("dayOfMonth("+"\""+"claimDate"+"\""+")").as("day")
                    .andExpression("month(claimDate)").as("month")
                    .andExpression("year(claimDate)").as("year"),
            group(fields().and("day").and("month").and("year"))
                    .count().as("count"));
AggregationResults<ClaimsAggregator> groupResults = mongoOperations.aggregate(aggregation, ClaimsAggregator.class);

但是它失败并发生以下异常：无法从BSON类型的String转换为Date

我的Applicate.class：

public class Applicate {

@Id
private String id;

private int claimId;

@DateTimeFormat (iso = DateTimeFormat.ISO.DATE)
private Date claimDate;

private int codeOfForm;
private String claimStatus;
private String fio;
private int claimantCategory;
private int serviceCode;
private String subserviceName;
private String departmentName;
//getter,setters, constructor
}

ClaimsAggregator.class：

public class ClaimsAggregator {
private String claimDate;
private int count;
....
}

燃料油

我找到了答案！如@chridam所建议，您需要替换该行

.andExpression("dayOfMonth("+"\""+"claimDate"+"\""+")").as("day")

有了这个

.andExpression("dayOfMonth(claimDate)").as("day")

现在您需要添加

.first("claimDate").as("claimDate")

到线

group(fields().and("day").and("month").and("year"))

最终代码：

TypedAggregation<Applicate> aggregation = newAggregation(Applicate.class,
            match(Criteria.where("claimantCategory").is(claimantCategory)),
            project("claimDate")
                    .andExpression("dayOfMonth(claimDate)").as("day")
                    .andExpression("month(claimDate)").as("month")
                    .andExpression("year(claimDate)").as("year"),
            group(fields().and("day").and("month").and("year")).first("claimDate").as("claimDate")
                    .count().as("count"));

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