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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: 8888
sharding:
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
*/
@Repository
public 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
*/
@Service
public 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
*/
@RestController
public 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…
正文完