最近想要学习一下分库分表，可是分库分表之前能够先用数据库的读写拆散来过渡一下，当然这还须要主从服务器来配合。明天就先写数据库的读写拆散，当前再介绍主从服务器。。。

Mysql

1. 新建三个数据库

CREATE DATABASE database0;USE database0;DROP TABLE IF EXISTS `user`;CREATE TABLE `user`(    id bigint(64) not null auto_increment,    city varchar(20) not null,    name varchar(20) not null,    PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;CREATE DATABASE database1;USE database1;DROP TABLE IF EXISTS `user`;CREATE TABLE `user`(    id bigint(64) not null auto_increment,    city varchar(20) not null,    name varchar(20) not null,    PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;INSERT INTO `database1`.`user`(`id`, `city`, `name`) VALUES (001, '青岛', '测试库1');CREATE DATABASE database2;USE database2;DROP TABLE IF EXISTS `user`;CREATE TABLE `user`(    id bigint(64) not null auto_increment,    city varchar(20) not null,    name varchar(20) not null,    PRIMARY KEY (`id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8;INSERT INTO `database2`.`user`(`id`, `city`, `name`) VALUES (002, '胶州', '测试库2');

2. 新建springboot我的项目

2.1 pom.xml
    <!-- web依赖 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-web</artifactId>        </dependency>        <!-- mybatis依赖 -->        <dependency>            <groupId>org.mybatis.spring.boot</groupId>            <artifactId>mybatis-spring-boot-starter</artifactId>            <version>2.1.3</version>        </dependency>        <!-- mysql依赖 -->        <dependency>            <groupId>mysql</groupId>            <artifactId>mysql-connector-java</artifactId>        </dependency>        <!-- druid数据库连接池依赖 -->        <dependency>            <groupId>com.alibaba</groupId>            <artifactId>druid-spring-boot-starter</artifactId>            <version>1.1.23</version>        </dependency>        <!-- ShardingSphere依赖 -->        <dependency>            <groupId>io.shardingsphere</groupId>            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>            <version>3.1.0</version>        </dependency>        <!-- jap依赖 -->        <dependency>            <groupId>org.springframework.boot</groupId>            <artifactId>spring-boot-starter-data-jpa</artifactId>        </dependency>
2.2 application.yml
server: # 端口号  port: 8888sharding:  jdbc:    dataSource:      names: db-test0,db-test1,db-test2      # 配置主库      db-test0:        type: com.alibaba.druid.pool.DruidDataSource        driverClassName: com.mysql.jdbc.Driver        url: jdbc:mysql://ip:3306/database0?useUnicode=true&characterEncoding=utf8&tinyInt1isBit=false&useSSL=false&serverTimezone=GMT        username: 账户        password: 明码        #最大连接数        maxPoolSize: 20      db-test1: # 配置第一个从库        type: com.alibaba.druid.pool.DruidDataSource        driverClassName: com.mysql.jdbc.Driver        url: jdbc:mysql://ip:3306/database1?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT        username: 账户        password: 明码        maxPoolSize: 20      db-test2: # 配置第二个从库        type: com.alibaba.druid.pool.DruidDataSource        driverClassName: com.mysql.jdbc.Driver        url: jdbc:mysql://ip:3306/database2?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT        username: 账户        password: 明码        maxPoolSize: 20    config:      masterslave: # 配置读写拆散        load-balance-algorithm-type: round_robin # 配置从库抉择策略，提供轮询与随机，这里抉择用轮询//random 随机 //round_robin 轮询        name: db1s2        master-data-source-name: db-test0        slave-data-source-names: db-test1,db-test2    props:      sql:        show: true # 开启SQL显示，默认值: false，留神：仅配置读写拆散时不会打印日志！！！spring:  main:    allow-bean-definition-overriding: true # 容许重名的bean能够被笼罩  jpa:    hibernate:      ddl-auto: update # 每次运行程序，没有表格会新建表格，表内有数据不会清空，只会更新      naming: # 驼峰命名法        physical-strategy: org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy    show-sql: true # 打印sql

2.3 新建User实体类

/** * 实体类 * * @author zhouzhaodong */@Entity@Table(name = "user")public class User implements Serializable {    @Id    @GeneratedValue(strategy = GenerationType.IDENTITY)    private Long id;    private String city;    private String name;    public Long getId() {        return id;    }    public void setId(Long id) {        this.id = id;    }    public String getCity() {        return city;    }    public void setCity(String city) {        this.city = city;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }}

2.4 新建 UserRepository

/** * 数据拜访层 * * @author zhouzhaodong */@Repositorypublic interface UserRepository extends JpaRepository<User, Long> {}

2.5 新建服务层UserService

/** * 服务层 * * @author zhouzhaodong */public interface UserService {    /**     * 新增     *     * @param user     * @return     */    User addUser(User user);    /**     * 查问所有     *     * @return     */    List<User> list();}

2.6 新建服务层实现类UserServiceImpl

/** * 服务层实现类 * * @author zhouzhaodong */@Servicepublic class UserServiceImpl implements UserService {    @Resource    UserRepository userRepository;    @Override    public User addUser(User user) {        // 强制路由主库//        HintManager.getInstance().setMasterRouteOnly();        return userRepository.save(user);    }    @Override    public List<User> list() {        return userRepository.findAll();    }}

2.7 新建管制层 UserController

/** * 管制层 * * @author zhouzhaodong */@RestControllerpublic class UserController {    @Resource    private UserService userService;    @GetMapping("/users")    public Object list() {        return userService.list();    }    @PostMapping("/add")    public Object add(String name, String city) {        User user = new User();        user.setCity(city);        user.setName(name);        return userService.addUser(user);    }}

2.8 启动类不须要任何操作

3. 启动我的项目进行测试即可

3.1 第一次拜访 localhost:8888/users

3.2 第二次拜访 localhost:8888/users

发现切换查询数据库了，胜利了！

3.3 存储数据

查看数据库会发现只有主库进行了新增，如果配置主从关系的话，从库也会进行新增的。不过咱们还没有进行配置。。。

好了，明天的教程就完结了！！！

集体博客

http://www.zhouzhaodong.xyz

源码地址：

https://github.com/zhouzhaodo...