概述

场景

建库、建表

CREATE TABLE `t_user` (
  `user_id` bigint(20) NOT NULL,
  `username` varchar(255) DEFAULT NULL,
  `ustatus` varchar(255) DEFAULT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

Springboot环境搭建

参考：ShardingSphere之水平分表实战（三）

编写代码

创建User实体类、mapper

package com.study.shardingjdbcdemo.entity;

import lombok.Data;

import javax.persistence.Id;
import javax.persistence.Table;

@Data
@Table(name = "t_user")
public class User {
    @Id
    private Long userId;
    private String username;
    private String ustatus;
}

package com.study.shardingjdbcdemo.mapper;

import com.study.shardingjdbcdemo.entity.User;
import org.springframework.stereotype.Repository;
import tk.mybatis.mapper.common.Mapper;

@Repository
public interface UserMapper extends Mapper<User> {
}

application.properties配置

# 配置分片策略
# 配置数据源
spring.shardingsphere.datasource.names=m0,m1,m2
spring.shardingsphere.datasource.m1.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.m1.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.m1.url=jdbc:mysql://localhost:3306/edu_db_1?serverTimezone=GMT%2B8
spring.shardingsphere.datasource.m1.username=root
spring.shardingsphere.datasource.m1.password=123456

spring.shardingsphere.datasource.m2.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.m2.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.m2.url=jdbc:mysql://localhost:3306/edu_db_2?serverTimezone=GMT%2B8
spring.shardingsphere.datasource.m2.username=root
spring.shardingsphere.datasource.m2.password=123456

spring.shardingsphere.datasource.m0.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.m0.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.m0.url=jdbc:mysql://localhost:3306/user_db?serverTimezone=GMT%2B8
spring.shardingsphere.datasource.m0.username=root
spring.shardingsphere.datasource.m0.password=123456

# 指定course表分布情况,配置表在哪个数据库中,表名称都是什么
spring.shardingsphere.sharding.tables.course.actual-data-nodes=m$->{1..2}.course_$->{1..2}
# 指定course主键cid生成策略SNOWFLAKE
spring.shardingsphere.sharding.tables.course.key-generator.column=cid
spring.shardingsphere.sharding.tables.course.key-generator.type=SNOWFLAKE
# 指定表分片策略, cid是偶数添加到course_1表中,cid是奇数添加到course_2
spring.shardingsphere.sharding.tables.course.table-strategy.inline.sharding-column=cid
spring.shardingsphere.sharding.tables.course.table-strategy.inline.algorithm-expression=course_$->{cid % 2 + 1}

# 指定库的中course表的分片策略
spring.shardingsphere.sharding.tables.course.database-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.tables.course.database-strategy.inline.algorithm-expression=m$->{user_id % 2 + 1}


# 指定t_user表分布情况,配置表在哪个数据库中,表名称都是什么
spring.shardingsphere.sharding.tables.t_user.actual-data-nodes=m0.t_user
# 指定t_user主键user_id生成策略SNOWFLAKE
spring.shardingsphere.sharding.tables.t_user.key-generator.column=user_id
spring.shardingsphere.sharding.tables.t_user.key-generator.type=SNOWFLAKE

# 指定表分片策略
spring.shardingsphere.sharding.tables.t_user.table-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.tables.t_user.table-strategy.inline.algorithm-expression=t_user


# 打开sql输出日志
spring.shardingsphere.props.sql.show=true
# 解决一个Course实体类不能对应两张表的问题
spring.main.allow-bean-definition-overriding=true

测试

@Test
    void addUser() {
        for (int i = 0; i < 10; i++) {
            User user = new User();
            user.setUsername("lucy");
            user.setUstatus("good");
            userMapper.insertSelective(user);
        }
    }

    @Test
    public void findUser() {
        Example example = new Example(User.class);
        Example.Criteria criteria = example.createCriteria();
        criteria.andEqualTo("userId", 760195997497294849L);
        User user  = userMapper.selectOneByExample(example);
        System.out.println(user);
    }