526互联

mybatis-plus多数据源

发布时间 2023-07-11 20:56:27作者: theSummerDay

目录

表结构及数据

-- 表结构
CREATE TABLE IF NOT EXISTS user
(
    `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键ID',
    `username` varchar(30) DEFAULT NULL COMMENT '姓名',
    `password` varchar(50) DEFAULT NULL COMMENT '密码',
    PRIMARY KEY (`id`),
    UNIQUE KEY `user_UN` (`username`)
);

-- h2数据库
INSERT INTO user (id, username, password) VALUES (1, 'adminH2', 'xxx'), (2, 'testH2', 'xxx');

-- MySQL数据库
INSERT INTO user (id, username, password) VALUES (1, 'admin', 'xxx'), (2, 'test', 'xxx');

依赖

        <!-- H2 -->
		<dependency>
			<groupId>com.h2database</groupId>
			<artifactId>h2</artifactId>
			<scope>runtime</scope>
		</dependency>
		
		<!-- MySQL -->
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
		</dependency>
		
		<!-- mybatis-plus -->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.5.3.1</version>
		</dependency>
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
			<version>3.6.1</version>
		</dependency>

配置

application.properties文件

spring.datasource.data=classpath:db/data-h2.sql
spring.datasource.schema=classpath:db/schema-h2.sql

#设置默认的数据源或者数据源组,默认值即为master
spring.datasource.dynamic.primary=h2
#严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
spring.datasource.dynamic.strict=false
#h2数据源,这里的h2可以根据需要自定义命名
spring.datasource.dynamic.datasource.h2.url=jdbc:h2:file:./db/test
spring.datasource.dynamic.datasource.h2.username=root
spring.datasource.dynamic.datasource.h2.password=xxx
spring.datasource.dynamic.datasource.h2.driver-class-name=org.h2.Driver
#mysql数据源,这里的mysql可以根据需要自定义命名
spring.datasource.dynamic.datasource.mysql.url=jdbc:mysql://192.168.111.222:3306/test?serverTimezone=Asia/Shanghai&characterEncoding=utf-8&autoReconnect=true&useSSL=false
spring.datasource.dynamic.datasource.mysql.username=root
spring.datasource.dynamic.datasource.mysql.password=xxx
spring.datasource.dynamic.datasource.mysql.driver-class-name=com.mysql.cj.jdbc.Driver

启动类添加@Mapper注解

在 Spring Boot 启动类中添加 @MapperScan 注解，扫描 Mapper 文件夹：

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.qq.multidatasource")
public class MultiDatasourceApplication {

	public static void main(String[] args) {
		SpringApplication.run(MultiDatasourceApplication.class, args);
	}

}

编码

实体类

import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

@Data
@TableName("user")
public class User {
    @TableId
    private Long id;
    private String username;
    private String password;
}

Mapper类

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.qq.multidatasource.entity.User;

public interface UserMapper extends BaseMapper<User> {

}

Service类

H2数据库操作

import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.qq.multidatasource.entity.User;
import com.qq.multidatasource.mapper.UserMapper;
import org.springframework.stereotype.Service;

//使用 @DS 切换数据源
//配置文件中设置h2是默认数据库,故这里可以不加@DS
//@DS("h2")
@Service
public class H2UserService extends ServiceImpl<UserMapper, User> {

}

MySQL数据库操作

import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.qq.multidatasource.entity.User;
import com.qq.multidatasource.mapper.UserMapper;
import org.springframework.stereotype.Service;

//使用 @DS 切换数据源
@DS("mysql")
@Service
public class MysqlUserService extends ServiceImpl<UserMapper, User> {

}

测试

@Test测试

import com.qq.multidatasource.entity.User;
import com.qq.multidatasource.service.H2UserService;
import com.qq.multidatasource.service.MysqlUserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.util.List;

@SpringBootTest
class MultiDatasourceApplicationTests {

	@Autowired
	private H2UserService h2UserService;

	@Autowired
	private MysqlUserService mysqlUserService;

	@Test
	void testH2() {
		List<User> h2List = h2UserService.list();
		System.out.println("查询H2:");
		h2List.forEach(System.out::println);

		System.out.println("查询MySQL:");
		List<User> mysqlList = mysqlUserService.list();
		mysqlList.forEach(System.out::println);
	}

}

测试结果

查询H2:
User(id=1, username=adminH2, password=xxx)
User(id=2, username=testH2, password=xxx)
查询MySQL:
User(id=1, username=admin, password=xxx)
User(id=2, username=test, password=xxx)

官网

参考:
https://baomidou.com/pages/a61e1b/

多数据源配置

spring:
  datasource:
    dynamic:
      primary: master #设置默认的数据源或者数据源组,默认值即为master
      strict: false #严格匹配数据源,默认false. true未匹配到指定数据源时抛异常,false使用默认数据源
      datasource:
        master:
          url: jdbc:mysql://xx.xx.xx.xx:3306/dynamic
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver # 3.2.0开始支持SPI可省略此配置
        slave_1:
          url: jdbc:mysql://xx.xx.xx.xx:3307/dynamic
          username: root
          password: 123456
          driver-class-name: com.mysql.jdbc.Driver
        slave_2:
          url: ENC(xxxxx) # 内置加密,使用请查看详细文档
          username: ENC(xxxxx)
          password: ENC(xxxxx)
          driver-class-name: com.mysql.jdbc.Driver
       #......省略
       #以上会配置一个默认库master，一个组slave下有两个子库slave_1,slave_2

# 多主多从                      纯粹多库（记得设置primary）                   混合配置
spring:                               spring:                               spring:
  datasource:                           datasource:                           datasource:
    dynamic:                              dynamic:                              dynamic:
      datasource:                           datasource:                           datasource:
        master_1:                             mysql:                                master:
        master_2:                             oracle:                               slave_1:
        slave_1:                              sqlserver:                            slave_2:
        slave_2:                              postgresql:                           oracle_1:
        slave_3:                              h2:                                   oracle_2:

@DS注解

@DS 可以注解在方法上或类上，同时存在就近原则 方法上注解 优先于 类上注解。

注解 结果
没有@DS 默认数据源
@DS("dsName") dsName可以为组名也可以为具体某个库的名称 
@Service
@DS("slave")
public class UserServiceImpl implements UserService {

  @Autowired
  private JdbcTemplate jdbcTemplate;

  public List selectAll() {
    return  jdbcTemplate.queryForList("select * from user");
  }
  
  @Override
  @DS("slave_1")
  public List selectByCondition() {
    return  jdbcTemplate.queryForList("select * from user where age >10");
  }
}