mybatis-plus分表实现案例

文章目录

- 文档说明
- 数据库水平分表思路
- - [1. 为什么要水平分表](#1. 为什么要水平分表)
  - [2. 核心设计要点](#2. 核心设计要点)
  - 3.基于数据库水平分表注意事项
- 示例代码
- - 测试表
  - pom依赖
  - properties配置
  - *mybatisplus分表实现类
  - 验证代码
  - 验证截图
  - - [验证mybatisplus内置构建SQL 动态分表](#验证mybatisplus内置构建SQL 动态分表)
    - [验证xml SQL 动态分表](#验证xml SQL 动态分表)
- 业务分库分表实现(mybatis-plus)

文档说明

基于springboot框架下mybatis-plus 3.5.5的分表案例和分表实现思路

数据库水平分表思路

1. 为什么要水平分表

java 复制代码

•单表数据量过大（千万/亿级）：索引膨胀、查询慢、写入压力大
•单机存储瓶颈：一张表的数据撑爆单库存储
•高并发读写：热点表（如订单表、日志表）写入成为瓶颈

2. 核心设计要点

① 确定分片键（Sharding Key）

java 复制代码

•分表路由的依据
•要保证每次数据操作都能带上分片键
•常见分片键：user_id、zone_code、tenant_id、时间字段

② 选择分片规则

java 复制代码

•范围分表
按时间区间（如 order_202501、order_202502）
   ✅ 适合日志、订单等时间序列数据
   ❌ 跨区间查询不方便

•哈希分表
对分片键取模（如 user_id % 8 → 8 张表）
   ✅ 分布均匀，避免热点
   ❌ 不方便做范围查询

•混合分表
先按业务维度（库级别），再在库内取模或按时间分表

3.基于数据库水平分表注意事项

java 复制代码

1.目前基于mybatis-plus分表方案，只能实现单次查询单表操作，如果涉及到单次查询跨表操作就必须引入三方组件来实现（ps：ShardingSphere ）
2.分页或者列表查询基于mybatis-plus组件不支持组件纬度跨片查询，此时只能从业务或者分片规则上做调整，比如以年份作为分片条件，列表查询强制要求用户选择时间再进行查询
3.库表必须预先创建好，预先规划好数据量
4.在触发分表操作前必须能拿到分片条件

示例代码

测试表

java 复制代码

-- ----------------------------
-- Table structure for user_1
-- ----------------------------
DROP TABLE IF EXISTS `user_1`;
CREATE TABLE `user_1`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `age` int(2) NULL DEFAULT NULL,
  `email` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Table structure for user_2
-- ----------------------------
DROP TABLE IF EXISTS `user_2`;
CREATE TABLE `user_2`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `age` int(2) NULL DEFAULT NULL,
  `email` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Table structure for user_3
-- ----------------------------
DROP TABLE IF EXISTS `user_3`;
CREATE TABLE `user_3`  (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `name` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `age` int(2) NULL DEFAULT NULL,
  `email` varchar(50) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

pom依赖

java 复制代码

        <dependency>
            <artifactId>gpmscloud-framework-mybatis-common</artifactId>
            <groupId>com.bosssoft.gpmscloud</groupId>
            <version>${gpmscloud.version}</version>
        </dependency>

properties配置

java 复制代码

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://192.168.xxx.xxx:xxxxx/gpx_basic?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&serverTimezone=GMT%2B8&useSSL=false&autoReconnect=true
spring.datasource.username=xxx
spring.datasource.password=xxx

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.druid.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.druid.url=jdbc:mysql://192.168.xxx.xxx:xxxxx/gpx_basic?useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull&serverTimezone=GMT%2B8&useSSL=false&autoReconnect=true
spring.datasource.druid.username=xxx
spring.datasource.druid.password=xxx

*mybatisplus分表实现类

java 复制代码

@Configuration
public class MybatisPlusBasicPlatformConfig {

    @Bean
    public MybatisPlusInterceptor multipleTablesBasicPlatformPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        DynamicTableNameInnerInterceptor dynamicTableNameInnerInterceptor = new DynamicTableNameInnerInterceptor();
        dynamicTableNameInnerInterceptor.setTableNameHandler((sql, tableName) -> {
            if (ThreadContextHandler.getThreadLocal().containsKey("tableType")) {
                String tableType = (String) ThreadContextHandler.getThreadLocal().get("tableType");
                return tableName + "_" + tableType;
            } else {
                throw new RuntimeException("未设置分表配置");
            }
        });
        interceptor.addInnerInterceptor(dynamicTableNameInnerInterceptor);
        return interceptor;
    }
}

验证代码

java 复制代码

@Data
@Accessors(chain = true)
@TableName(value = "user")
public class User {

    private Long id;
    private String name;
    private Integer age;
    private String email;
}

public interface UserMapper extends BaseMapper<User> {

    User test();

    User test2();
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.bosssoft.gpmscloud.framework.test.mapper.UserMapper">

    <resultMap type="com.bosssoft.gpmscloud.framework.test.model.po.User" id="UserMapper">
        <result property="id" column="id" jdbcType="INTEGER"/>
        <result property="name" column="resource_id" jdbcType="VARCHAR"/>
        <result property="age" column="white_list" jdbcType="INTEGER"/>
        <result property="email" column="black_list" jdbcType="VARCHAR"/>
    </resultMap>

    <select id="test" resultMap="UserMapper" parameterType="java.lang.String">
        select id, name, age, email from user
    </select>

    <select id="test2" resultMap="UserMapper" parameterType="java.lang.String">
        select u1.id, u2.name, u2.age, u2.email from user u1
        left join user u2 on u1.user_id = u2.user_id
    </select>


</mapper>


@RestController
@Slf4j
@RequestMapping("/test/multipleTables")
public class MultipleTablesController {

    @Resource
    private UserMapper userMapper;

    /**
     * 验证自动生成库表
     */
    @ApiOperation("test")
    @GetMapping("/test")
    public Result<Boolean> testQuery() {
        ThreadContextHandler.getThreadLocal().put("tableType", "1");
        userMapper.selectList(null);

        ThreadContextHandler.getThreadLocal().put("tableType", "2");
        User user = new User();
        user.setId(1L);
        user.setName("Name");
        user.setAge(1);
        user.setEmail("EMAIL");
        userMapper.insert(user);

        ThreadContextHandler.getThreadLocal().put("tableType", "2");
        userMapper.deleteById(1L);

        ThreadContextHandler.getThreadLocal().put("tableType", "3");
        userMapper.selectList(null);
        return Result.ok(true);
    }

    /**
     * 验证单表和多表自定义xml操作
     */
    @ApiOperation("testXml")
    @GetMapping("/testXml")
    public Result<Boolean> testXml() {
        ThreadContextHandler.getThreadLocal().put("tableType", "2");
        userMapper.test();
        userMapper.test2();
        return Result.ok(true);
    }
}

验证截图

验证mybatisplus内置构建SQL 动态分表

验证xml SQL 动态分表

业务分库分表实现(mybatis-plus)

java 复制代码

1.基于上下文内tableType数据进行分表读写，这里需要注意Configuration类命名最好带上服务名,MybatisPlusInterceptor类也是，这样主要是为了避免bean名称冲突
2.业务可以通过上下文参数进行分表参数传递

java 复制代码

@Configuration
public class MybatisPlusBasicPlatformConfig {

    @Bean
    public MybatisPlusInterceptor multipleTablesBasicPlatformPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        DynamicTableNameInnerInterceptor dynamicTableNameInnerInterceptor = new DynamicTableNameInnerInterceptor();
        dynamicTableNameInnerInterceptor.setTableNameHandler((sql, tableName) -> {
            if (ThreadContextHandler.getThreadLocal().containsKey("tableType")) {
                String tableType = (String) ThreadContextHandler.getThreadLocal().get("tableType");
                return tableName + "_" + tableType;
            } else {
                throw new RuntimeException("未设置分表配置");
            }
        });
        interceptor.addInnerInterceptor(dynamicTableNameInnerInterceptor);
        return interceptor;
    }
}