Basic operations on MongoDB in SpringBoot

Creation of Database Library

Firstly, the database is created in the MongoDB operation client Robo 3T:

Add User:

Create Collections collections (similar to tables in mysql):

Most of the rest of us are based on the Collection "collection emo" operation created.

Dependency package

  <dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-data-mongodb</artifactId>
			<version> 2.1.7.RELEASE</version>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
			<version> 2.1.7.RELEASE</version>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<version> 2.1.7.RELEASE</version>
		</dependency>
	</dependencies>

application.properties file configuration in SpringBoot

spring.data.mongodb.host=localhost
spring.data.mongodb.port=27017
spring.data.mongodb.database=mongodemo
spring.data.mongodb.username=login
spring.data.mongodb.password=login

Addition, deletion and alteration checking operations in MongoDB

Define MongoTemplate

	 @Autowired
	private MongoTemplate mongoTemplate;

	private static String COLLECTION_DEMO = "collectiondemo";

mongoTemplate-based operation

Add data

   @PostMapping("/insertDocument")
	public void insertDocument(String document) {
		//Get set
		MongoCollection<Document> collection = mongoTemplate.getCollection(COLLECTION_DEMO);
		Document parse = Document.parse(document);
		//Insert document
		collection.insertOne(parse);
	}

Posman test parameters:

In Robo, you can find:

Successful addition of data, where ObjectId is a 12-byte BSON type string, by

Form

insert data

	@PutMapping("/updateDocument")
	public Long updateDocument(String queryDocument, String ducument) {
		MongoCollection<Document> collection = mongoTemplate.getCollection(COLLECTION_DEMO);
		BasicDBObject queryParse = BasicDBObject.parse(queryDocument);
		BasicDBObject parse = BasicDBObject.parse(ducument);
		UpdateResult result = collection.updateOne(queryParse, new BasicDBObject("$set",parse));
		return result.getModifiedCount();
	}

Input parameters:

As you can see:

But there is a problem, when the key in the parameter does not exist in mongodb, it creates itself:

mongodb did not have an age field before, and now you can see that:

For some business scenarios, a strict key requirement can't be met. In this case, mongodb can be solved with $exists:

	@PutMapping("/updateDocumentOnlyHave")
	public Long updateDocumentOnlyHave(String id, String ducument) {
		MongoCollection<Document> collection = mongoTemplate.getCollection(COLLECTION_DEMO);
		BasicDBObject parse = BasicDBObject.parse(ducument);
		Set<String> keySet = parse.keySet();
		BasicDBObject dbObject = new BasicDBObject();
		dbObject.put("id",id);
		for (String key : keySet) {
			dbObject.put(key, new BasicDBObject("$exists",true));
		}
		UpdateResult result = collection.updateOne(dbObject, new BasicDBObject("$set",parse));
		return result.getModifiedCount();
	}

Query data

	@GetMapping("/listDocuments")
	public List<Document> findDocuments() {
		MongoCollection<Document> collection = mongoTemplate.getCollection(COLLECTION_DEMO);
		FindIterable<Document> documents = collection.find();
		List<Document> listDocuments = new ArrayList<>();
		for (Document document : documents) {
			listDocuments.add(document);
		}
		return listDocuments;
	}

Delete data

  @DeleteMapping("/deleteDocument")
	public DeleteResult deleteDocument(String name) {
		MongoCollection<Document> collection = mongoTemplate.getCollection(COLLECTION_DEMO);
		DeleteResult result = collection.deleteOne(new BasicDBObject("name", name));
		return result;
	}