Spring Boot integrates with a number of data technologies, both SQL and NoSQL.

SQL Databases

Spring Data provides an additional level of functionality: creating Repository implementations directly from interfaces and using conventions to generate queries from your method names.

The spring-boot-starter-data-jpa POM provides a quick way to get started. It provides the following key dependencies:

• Hibernate: One of the most popular JPA implementations.

• Spring Data JPA: Helps you to implement JPA-based repositories.

• Spring ORM: Core ORM support from the Spring Framework.

A typical entity class resembles the following example:

import java.io.Serializable;

import jakarta.persistence.Column;
import jakarta.persistence.Entity;
import jakarta.persistence.GeneratedValue;
import jakarta.persistence.Id;

@Entity
public class City implements Serializable {

    @Id
    @GeneratedValue
    private Long id;

    @Column(nullable = false)
    private String name;

    @Column(nullable = false)
    private String state;

    // ... additional members, often include @OneToMany mappings

    protected City() {
        // no-args constructor required by JPA spec
        // this one is protected since it should not be used directly
    }

    public City(String name, String state) {
        this.name = name;
        this.state = state;
    }

    public String getName() {
        return this.name;
    }

    public String getState() {
        return this.state;
    }

    // ... etc

}

Working with NoSQL Technologies

Redis

Redis is a cache, message broker, and richly-featured key-value store. Spring Boot offers basic auto-configuration for the Lettuceand Jedis client libraries and the abstractions on top of them provided by Spring Data Redis.

By default, the instance tries to connect to a Redis server at localhost:6379.

spring.data.redis.host=localhost
spring.data.redis.port=6379
spring.data.redis.database=0
spring.data.redis.username=user
spring.data.redis.password=secret

MongoDB

The auto-configured MongoClient is created using a MongoClientSettings bean.

spring.data.mongodb.host=mongoserver1.example.com
spring.data.mongodb.port=27017
spring.data.mongodb.additional-hosts[0]=mongoserver2.example.com:23456
spring.data.mongodb.database=test
spring.data.mongodb.username=user
spring.data.mongodb.password=secret

Elasticsearch

Spring Boot supports several clients:

• The official low-level REST client

• The official Java API client

• The ReactiveElasticsearchClient provided by Spring Data Elasticsearch

spring.elasticsearch.uris=https://search.example.com:9200
spring.elasticsearch.socket-timeout=10s
spring.elasticsearch.username=user
spring.elasticsearch.password=secret

InfluxDB

InfluxDB is an open-source time series database optimized for fast, high-availability storage and retrieval of time series data in fields such as operations monitoring, application metrics, Internet-of-Things sensor data, and real-time analytics.

spring.influx.url=https://172.0.0.1:8086

参考资料：

https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#data