Mybatis-Plus 配置多数据源

原创已于 2024-03-04 11:13:10 修改 · 2.1k 阅读

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于 2019-03-15 17:26:41 首次发布

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本文介绍如何使用 MyBatis Plus 和 dynamic-datasource-spring-boot-starter 实现多数据源配置，包括不同数据库不同表及相同表的场景，详细展示了配置过程、依赖引入、服务实现及测试方法。

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一、背景

适用于以下场景：纯粹多库、读写分离、一主多从、混合模式等。

二、不同数据库不同的表

2.1 创建库表

CREATE DATABASE `mybatis_plus` /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
use `mybatis_plus`;
CREATE TABLE `user` (
	`uid` bigint(20) NOT NULL COMMENT '主键ID',
	`user_name` varchar(30) DEFAULT NULL COMMENT '姓名',
	`age` int(11) DEFAULT NULL COMMENT '年龄',
	`email` varchar(50) DEFAULT NULL COMMENT '邮箱',
	`sex` varchar(30) DEFAULT NULL COMMENT '性别',
	`is_deleted` int(11) DEFAULT NULL COMMENT '是否删除',
	PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
INSERT INTO user (uid, user_name, age, email,sex,is_deleted) VALUES
	(1, 'Jone', 18, 'test1@baomidou.com','男','0'),
	(2, 'Jack', 20, 'test2@baomidou.com','女','0'),
	(3, 'Tom', 28, 'test3@baomidou.com','男','0'),
	(4, 'Sandy', 21, 'test4@baomidou.com','女','0'),
	(5, 'Billie', 24, 'test5@baomidou.com','男','0');
	
	
CREATE DATABASE `mybatis_plus_1` /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
use `mybatis_plus_1`;
CREATE TABLE product
(
	id BIGINT(20) NOT NULL COMMENT '主键ID',
	name VARCHAR(30) NULL DEFAULT NULL COMMENT '商品名称',
	price INT(11) DEFAULT 0 COMMENT '价格',
	version INT(11) DEFAULT 0 COMMENT '乐观锁版本号',
	PRIMARY KEY (id)
);

INSERT INTO product (id, NAME, price) VALUES (1, '外星人笔记本', 100);

2.2 引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.6.3</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.datasource</groupId>
	<artifactId>mybatis_plus_datasource</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>mybatis_plus_datasource</name>
	<description>mybatis_plus_datasource</description>
	<properties>
		<java.version>8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<!-- 引入 mybatis plus 依赖-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.5.1</version>
		</dependency>
		<!-- 引入 lombok 依赖-->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-generator</artifactId>
			<version>3.5.1</version>
		</dependency>
		<dependency>
			<groupId>org.freemarker</groupId>
			<artifactId>freemarker</artifactId>
			<version>2.3.31</version>
		</dependency>
		<!-- 配置多数据源的依赖-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
			<version>3.5.0</version>
		</dependency>
	</dependencies>
</project>

2.3 编写配置文件

spring:
  # 配置数据源信息
  datasource:
    dynamic:
      # 设置默认的数据源或者数据源组,默认值即为 master
      primary: master
      # 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
      strict: false
      datasource:
        master:
          url: jdbc:mysql://localhost:3306/mybatis_plus?characterEncoding=utf-8&useSSL=false
          driver-class-name: com.mysql.cj.jdbc.Driver
          username: root
          password: 123456
        slave_1:
          url: jdbc:mysql://localhost:3306/mybatis_plus_1?characterEncoding=utf-8&useSSL=false
          driver-class-name: com.mysql.cj.jdbc.Driver
          username: root
          password: 123456

2.4 创建 mapper 文件

package com.datasource.mapper;


import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.datasource.entity.Product;
import org.springframework.stereotype.Repository;

@Repository
public interface ProductMapper extends BaseMapper<Product> {

}

package com.datasource.mapper;


import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.datasource.entity.User;
import org.springframework.stereotype.Repository;

@Repository
public interface UserMapper extends BaseMapper<User> {

}

2.5 创建 service 文件

package com.datasource.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.datasource.entity.User;

public interface UserService extends IService<User> {

}

package com.datasource.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.datasource.entity.Product;

public interface ProductService extends IService<Product> {
}

package com.datasource.service.impl;

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

@DS("master") //指定所操作的数据源
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

}

package com.datasource.service.impl;

import com.baomidou.dynamic.datasource.annotation.DS;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.datasource.entity.Product;
import com.datasource.mapper.ProductMapper;
import com.datasource.service.ProductService;
import org.springframework.stereotype.Service;

@DS("slave_1")
@Service
public class ProductServiceImpl extends ServiceImpl<ProductMapper, Product> implements ProductService {

}

2.6 测试

package com.datasource.mybatis_plus_datasource;

import com.datasource.service.ProductService;
import com.datasource.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class MybatisPlusDatasourceApplicationTests {

	@Test
	void contextLoads() {
	}
	@Autowired
	private UserService userService;
	@Autowired
	private ProductService productService;

	@Test
	public void testDynamicDataSource(){
		System.out.println(userService.getById(1L));
		System.out.println(productService.getById(1L));
	}
}

结果如下：

三、不同数据库相同的表

3.1 创建库表

CREATE DATABASE `mybatis_plus` /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
use `mybatis_plus`;
CREATE TABLE `user` (
	`uid` bigint(20) NOT NULL COMMENT '主键ID',
	`user_name` varchar(30) DEFAULT NULL COMMENT '姓名',
	`age` int(11) DEFAULT NULL COMMENT '年龄',
	`email` varchar(50) DEFAULT NULL COMMENT '邮箱',
	`sex` varchar(30) DEFAULT NULL COMMENT '性别',
	`is_deleted` int(11) DEFAULT NULL COMMENT '是否删除',
	PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
 
INSERT INTO user (uid, user_name, age, email,sex,is_deleted) VALUES
	(1, 'Jone', 18, 'test1@baomidou.com','男','0'),
	(2, 'Jack', 20, 'test2@baomidou.com','女','0');
	
	
CREATE DATABASE `mybatis_plus_1` /*!40100 DEFAULT CHARACTER SET utf8mb4 */;
use `mybatis_plus_1`;
CREATE TABLE `user` (
	`uid` bigint(20) NOT NULL COMMENT '主键ID',
	`user_name` varchar(30) DEFAULT NULL COMMENT '姓名',
	`age` int(11) DEFAULT NULL COMMENT '年龄',
	`email` varchar(50) DEFAULT NULL COMMENT '邮箱',
	`sex` varchar(30) DEFAULT NULL COMMENT '性别',
	`is_deleted` int(11) DEFAULT NULL COMMENT '是否删除',
	PRIMARY KEY (`uid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

INSERT INTO user (uid, user_name, age, email,sex,is_deleted) VALUES	
	(3, 'Tom', 28, 'test3@baomidou.com','男','0'),
	(4, 'Sandy', 21, 'test4@baomidou.com','女','0');

3.2 引入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.6.3</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.datasource</groupId>
	<artifactId>mybatis_plus_datasource</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>mybatis_plus_datasource</name>
	<description>mybatis_plus_datasource</description>
	<properties>
		<java.version>8</java.version>
	</properties>
	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
		<!-- 引入 mybatis plus 依赖-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-boot-starter</artifactId>
			<version>3.5.1</version>
		</dependency>
		<!-- 引入 lombok 依赖-->
		<dependency>
			<groupId>org.projectlombok</groupId>
			<artifactId>lombok</artifactId>
			<optional>true</optional>
		</dependency>
		<dependency>
			<groupId>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>mybatis-plus-generator</artifactId>
			<version>3.5.1</version>
		</dependency>
		<dependency>
			<groupId>org.freemarker</groupId>
			<artifactId>freemarker</artifactId>
			<version>2.3.31</version>
		</dependency>
		<!-- 配置多数据源的依赖-->
		<dependency>
			<groupId>com.baomidou</groupId>
			<artifactId>dynamic-datasource-spring-boot-starter</artifactId>
			<version>3.5.0</version>
		</dependency>
	</dependencies>
</project>

3.3 编写配置文件

spring:
  # 配置数据源信息
  datasource:
    dynamic:
      # 设置默认的数据源或者数据源组,默认值即为 master
      primary: master
      # 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
      strict: false
      datasource:
        master:
          url: jdbc:mysql://localhost:3306/mybatis_plus?characterEncoding=utf-8&useSSL=false
          driver-class-name: com.mysql.cj.jdbc.Driver
          username: root
          password: 123456
        slave_1:
          url: jdbc:mysql://localhost:3306/mybatis_plus_1?characterEncoding=utf-8&useSSL=false
          driver-class-name: com.mysql.cj.jdbc.Driver
          username: root
          password: 123456

2.4 创建 mapper 文件

package com.datasource.mapper;


import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.datasource.entity.User;
import org.springframework.stereotype.Repository;

@Repository
public interface UserMapper extends BaseMapper<User> {

}

2.5 创建 service 文件

package com.datasource.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.datasource.entity.User;

public interface UserService extends IService<User> {

    User getById(Long id);

    User getByIdTwo(Long id);
}

package com.datasource.service.impl;

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

@DS("master") //指定所操作的数据源
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {


    @Override
    public User getById(Long id) {
        return super.getById(id);
    }

    // @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
    @Override
    @DS("slave")
    public User getByIdTwo(Long id) {
        return super.getById(id);
    }
}

2.6 测试

package com.datasource.mybatis_plus_datasource;

import com.datasource.service.UserService;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class MybatisPlusDatasourceApplicationTests {

	@Test
	void contextLoads() {
	}
	@Autowired
	private UserService userService;

	@Test
	public void testDynamicDataSource(){
		System.out.println(userService.getById(1L));
		System.out.println(userService.getByIdTwo(3L));
	}
}

输出结果如下：