Mongo 查询不适用于嵌入式文档 [英] Mongo query is not working for embedded documents

问题描述

我正在使用 Spring Data Mongo 和简单的 mongo 查询来获取活动状态部门的列表.

I'm using Spring Data Mongo and simple mongo query to get the list of Active Status departments.

当我使用下面的查询时，它仍然拉取 InActive 记录.

When I used below query, it still pulling the InActive records too.

db.getCollection('employee').find({"departments.status" : "A"})

样本数据 -

{
    "firstName" : "Sichita",
    "lastName" : "Vinchurkar",
    "email" : "[e-mail]",
    "departments" : [ 
        {
            "deptName" : "IT Support",
            .......
            .......
            "status" : "A"
        }, 
        {
            "deptName" : "Mobile Development",
            .......
            .......
            "status" : "I"
        }, 
        {
            "deptName" : "Advisory Dept",
            .......
            .......
            "status" : "A"
        },
        .........
        ..........
        .........
}

推荐答案

解决方案是使用聚合与 MongoDB Spring Data (v2.2.6) MongoTemplate API.您无法使用 find 查询(因此使用聚合的 $filter 数组运算符)基于条件检索特定数组元素.

The solution is using an aggregation with MongoDB Spring Data (v2.2.6) MongoTemplate API. You cannot retrieve specific array elements based a condition using a find query (so using the aggregation's $filter array operator).

MongoOperations mongoOps = new MongoTemplate(MongoClients.create(), "test");
Aggregation agg = newAggregation(
    match(Criteria.where("departments.status").is("A")),
    project()
        .and(filter("departments")
                .as("dept")
                .by(Eq.valueOf("dept.status").equalToValue("A")))
    .as("departments")
);

AggregationResults<Document> results = mongoOps.aggregate(agg, "collection", Document.class);
results.forEach(doc -> System.out.println(doc.toJson()));

包括代码中使用的类和接口的import语句:

Including the import statements for the classes and interfaces used in the code:

import org.springframework.data.mongodb.core.MongoOperations;
import org.springframework.data.mongodb.core.MongoTemplate;
import org.springframework.data.mongodb.core.aggregation.Aggregation;
import org.springframework.data.mongodb.core.aggregation.AggregationResults;

import static org.springframework.data.mongodb.core.aggregation.Aggregation.newAggregation;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.match;
import static org.springframework.data.mongodb.core.aggregation.Aggregation.project;
import static org.springframework.data.mongodb.core.aggregation.ArrayOperators.Filter.filter;
import static org.springframework.data.mongodb.core.aggregation.ComparisonOperators.Eq;

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