Mongodb学习笔记2

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前言

MongoTemplate 相关操作 CRUD,聚合查询等;

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一、搭建项目

• springboot项目创建
• 引入mongo 依赖
• docker 安装好mongo数据库
• 配置yml 链接mongo

spring:data:mongodb:host: 127.0.0.1port: 27017database: test

pom/gradle MongoTemplate 版本: 2.6.3

spring-boot-starter-data-mongodb

mongo可视化工具 robo3t

二、开始编写java代码

1. 新增

  @AutowiredMongoTemplate mongoTemplate;@Testvoid add() {List<ApplicationEntity> applicationEntityList = init();Collection<ApplicationEntity> applicationEntities = mongoTemplate.insert(applicationEntityList, ApplicationEntity.class);log.info("存储成功: {}", JSONUtil.toJsonStr(mongoTemplate.findAll(ApplicationEntity.class)));}private List<ApplicationEntity> init() {List<ApplicationEntity> applicationEntityList = CollectionUtil.newArrayList();for (int i = 0; i < 2; i++) {String id = IdUtil.fastSimpleUUID();String name = "第" + RandomUtil.randomNumbers(2) + "个应用";ApplicationEntity applicationEntity = ApplicationEntity.builder().id(id).name(name).orgName(name).icon("https://www.baidu.com").status(RandomUtil.randomBoolean() ? "启用" : "禁用").type("application").build();applicationEntityList.add(applicationEntity);}return applicationEntityList;}

实体具体内容

2.查询

 @AutowiredMongoTemplate mongoTemplate;@Testvoid queryField() {Query query1 = new Query();query1.fields().include("orgName", "name");List<ApplicationEntity> applicationEntities = mongoTemplate.find(query1, ApplicationEntity.class);System.out.println(JSONUtil.toJsonStr(applicationEntities));}

1 include 查询指定字段,可以不指定,查询所有字段
2 ApplicationEntity 对应mongo数据库中的一个document

3. 修改

找到要修改的,并修改

  @Testvoid update() {ApplicationDto applicationDto = new ApplicationDto();applicationDto.setId("b8cbf05d102e454784ab85f23704bfb7");applicationDto.setName("测试");applicationDto.setStatus("启用");applicationDto.setIcon("www.tupian");Query query = new Query(Criteria.where("id").is(applicationDto.getId()));Update update = new Update();update.set("fileUrl", applicationDto.getIcon());update.set("name", applicationDto.getName());update.set("status", applicationDto.getStatus());mongoTemplate.updateFirst(query, update, ApplicationEntity.class);List<ApplicationEntity> all = mongoTemplate.findAll(ApplicationEntity.class);System.out.println(JSONUtil.toJsonStr(all));}

4. 删除

找到并删除

    Criteria criteria = Criteria.where("pid").is(applicationDto.getId());mongoTemplate.findAllAndRemove(new Query(criteria), MenuNavigationEntity.class);

5.根据条件查询

相当于
select * from a where id=1 or id =2;

   @Testvoid queryCondition() {Query query1 = new Query(new Criteria().orOperator(Criteria.where("id").is("923406"), Criteria.where("id").is("3518177")));List<MenuNavigationEntity> menuNavigationEntityList = mongoTemplate.find(query1, MenuNavigationEntity.class);System.out.println(JSONUtil.toJsonStr(menuNavigationEntityList));}

6. 关联查询

相当于
select *
from a
left join b on a.id = b.pid;

    @Testvoid queryLink() {LookupOperation lookupOperation = LookupOperation.newLookup().from("menu_navigation")// 副表名称.localField("_id")// 主表关联字段.foreignField("pid")// 副表关联字段.as("menu_navigation");// 副表别名// 聚合条件Aggregation aggregation = Aggregation.newAggregation(lookupOperation,Aggregation.match(Criteria.where("menu_navigation.pid")// 副表关联的主表条件.is("b8cbf05d102e454784ab85f23704bfb7")));AggregationResults<JSONObject> aggregate = mongoTemplate.aggregate(aggregation, ApplicationEntity.class,JSONObject.class);// 条件  主表类型  结果类型List<JSONObject> mappedResults = aggregate.getMappedResults();System.out.println(JSONUtil.toJsonStr(mappedResults));}

7. 索引相关

    @Testvoid index() {MongoCollection<Document> collection = mongoTemplate.getCollection("application");collection.createIndex(new Document("id", "hashed"), new IndexOptions().name("index_id"));// 唯一索引collection.createIndex(new Document("id", "hashed"), new IndexOptions().unique(true).name("index_id"));// 删除指定索引collection.dropIndex("index_id");// 删除所有索引collection.dropIndexes();}

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总结

主要是展示了 MongoTemplate 中的CRUD的常规操作和 关联查询,之后会继续学习~~
还有个问题,就是我无法从已经标记为 文档的实体中获取 集合名称嘛? 现在我的代码中的集合名称都是字符串
还有就是字段名称也都是字符串,可以从这个 document 中获取嘛?