Spring Boot 数据库访问简介

对于数据访问层，无论是 SQL(关系型数据库) 还是 NOSQL(非关系型数据库)，Spring Boot 底层都是采用 Spring Data 的方式进行统一处理。
Spring Boot 添加了大量自动配置，屏蔽了很多设置，引入各种 XxxTemplate，XxxRepository 来简化程序员对数据访问层的操作。
对程序员来说只需要进行简单的配置即可使用

Spring Data

Spring Boot 底层都是采用 Spring Data 的方式进行统一处理各种数据库，Spring Data 也是 Spring 中与 Spring Boot、Spring Cloud 等齐名的知名项目。
Sping Data 官网：https://spring.io/projects/spring-data

Overview

Spring Data’s mission is to provide a familiar and consistent, Spring-based programming model for data access while still retaining the special traits of the underlying data store.

It makes it easy to use data access technologies, relational and non-relational databases, map-reduce frameworks, and cloud-based data services. This is an umbrella project which contains many subprojects that are specific to a given database. The projects are developed by working together with many of the companies and developers that are behind these exciting technologies.

Features

Powerful repository and custom object-mapping abstractions
Dynamic query derivation from repository method names
Implementation domain base classes providing basic properties
Support for transparent auditing (created, last changed)
Possibility to integrate custom repository code
Easy Spring integration via JavaConfig and custom XML namespaces
Advanced integration with Spring MVC controllers
Experimental support for cross-store persistence

Community modules

Spring Data Aerospike - Spring Data module for Aerospike.
Spring Data ArangoDB - Spring Data module for ArangoDB.
Spring Data Couchbase - Spring Data module for Couchbase.
Spring Data Azure DocumentDB - Spring Data module for Microsoft Azure DocumentDB.
Spring Data DynamoDB - Spring Data module for DynamoDB.
Spring Data Elasticsearch - Spring Data module for Elasticsearch.
Spring Data Hazelcast - Provides Spring Data repository support for Hazelcast.
Spring Data Jest - Spring Data for Elasticsearch based on the Jest REST client.
Spring Data Neo4j - Spring based, object-graph support and repositories for Neo4j.
Spring Data Vault - Vault repositories built on top of Spring Data KeyValue.

Spring Data JDBC Extensions - Provides extensions to the JDBC support provided in the Spring Framework.
Spring for Apache Hadoop - Simplifies Apache Hadoop by providing a unified configuration model and easy to use APIs for using HDFS, MapReduce, Pig, and Hive.
Spring Content - Associate content with your Spring Data Entities and store it in a number of different stores including the File-system, S3, Database or Mongo’s GridFS.

Release train

Spring Data is an umbrella project consisting of independent projects with, in principle, different release cadences. To manage the portfolio, a BOM (Bill of Materials - see this example) is published with a curated set of dependencies on the individual project. The release trains have names, not versions, to avoid confusion with the sub-projects.

The names are an alphabetic sequence (so you can sort them chronologically) with names of famous computer scientists and software developers. When point releases of the individual projects accumulate to a critical mass, or if there is a critical bug in one of them that needs to be available to everyone, the release train will push out “service releases” with names ending “-SRX”, where “X” is a number.

Currently the release train contains the following modules:

Spring Data Commons
Spring Data JPA
Spring Data KeyValue
Spring Data LDAP
Spring Data MongoDB
Spring Data Gemfire
Spring Data for Apache Geode
Spring Data REST
Spring Data Redis
Spring Data for Apache Cassandra
Spring Data for Apache Solr
Spring Data Couchbase (community module)
Spring Data Elasticsearch (community module)
Spring Data Neo4j (community module)

Spring Boot 数据库启动器

可以参考官方文档：https://docs.spring.io/spring-boot/docs/2.0.4.RELEASE/reference/htmlsingle/#using-boot-starter