使用Apache ShardingSphere简答实现水平分表

1 简介

Apache ShardingSphere 是一款分布式的数据库生态系统，可以将任意数据库转换为分布式数据库，并通过数据分片、弹性伸缩、加密等能力对原有数据库进行增强。

官方网站

https://shardingsphere.apache.org/document/current/cn/overview/

2 创建数据库和表

# 创建数据库
CREATE DATABASE mytest DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;

# 创建表
CREATE TABLE article_1 (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
	title VARCHAR(50) NOT NULL,
	summary VARCHAR(300) NOT NULL,
	keywords VARCHAR(100) NOT NULL,
    create_time timestamp not null default CURRENT_TIMESTAMP COMMENT '创建时间',
    update_time timestamp not null default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP COMMENT '更新时间'
) ENGINE=INNODB DEFAULT CHARSET=utf8;

# 创建表
CREATE TABLE article_2 (
    id BIGINT PRIMARY KEY AUTO_INCREMENT,
	title VARCHAR(50) NOT NULL,
	summary VARCHAR(300) NOT NULL,
	keywords VARCHAR(100) NOT NULL,
    create_time timestamp not null default CURRENT_TIMESTAMP COMMENT '创建时间',
    update_time timestamp not null default CURRENT_TIMESTAMP on update CURRENT_TIMESTAMP COMMENT '更新时间'
) ENGINE=INNODB DEFAULT CHARSET=utf8;

3 工程目录

[ 在这里插入图片描述

4 源代码

注意的问题：

（1）不要使用druid-spring-boot-starter自动装配，直接使用“druid”即可；

（2）我用的shardingsphere-jdbc-core-spring-boot-starter版本是5.0.0，测试5.1.0和5.2.0一直报错，不知道什么原因

4.1 pom.xml

<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.mason</groupId>
    <artifactId>subtable</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
    </properties>

    <dependencies>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
            <version>2.3.12.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.20</version>
            <scope>provided</scope>
        </dependency>

        <!-- Operate the mysql -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.21</version>
        </dependency>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.2</version>
        </dependency>

        <!-- 引入druid -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.2.15</version>
        </dependency>

        <!-- druid不要使用下面的自动装配 -->
        <!--
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.4</version>
        </dependency>
        -->

        <!-- shardingsphere -->
        <dependency>
            <groupId>org.apache.shardingsphere</groupId>
            <artifactId>shardingsphere-jdbc-core-spring-boot-starter</artifactId>
            <version>5.0.0</version>
        </dependency>

    </dependencies>


    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

4.2 application.yml

注意：配置数据库和表是重点

# 数据库分表

spring:
  application:
    name: subtable

  shardingsphere:
    # 显示sql
    props:
      sql:
        show: true


    datasource:
      # 连接多个数据库时，可以设置多个names和datasource
      # names: db1,db2

      # 连接单个数据库
      names: mytest

      mytest:
        # 连接数据库
        url: jdbc:mysql://192.168.108.200:3306/mytest?useUnicode=true&&characterEncoding=utf-8&&useSSL=false
        username: root
        password: 123456
        driver-class-name: com.mysql.cj.jdbc.Driver

        # set druid
        type: com.alibaba.druid.pool.DruidDataSource

        druid:
          initial-size: 5
          min-idle: 5
          max-active: 20
          max-wait: 6000
          time-between-eviction-runs-millis: 60000
          min-evictable-idle-time-millis: 30000
          test-on-borrow: false
          test-on-return: false
          pool-prepared-statements: true
          max-pool-prepared-statement-per-connection-size: 20

    # 配置规则
    rules:

      # 配置分片
      sharding:


        # 设置主键生成策略
        key-generators:
          # 自定义主键生成算法名称
          snowflake:
            type: SNOWFLAKE

        # 自定义分片算法
        sharding-algorithms:
          # 自定义分片算法名称
          article-strategy-inline:
            type: INLINE
            props:
              algorithm-expression: article_$->{id % 2 + 1}

        # 配置表
        tables:
          # 自定义的表名
          article:
            # 配置数据库和全部的表
            # 含有article_1, article_2两个表
            actual-data-nodes: mytest.article_$->{1..2}

            # 主键生成策略
            key-generate-strategy:
              # 对应article表中自定义的字段
              column: id
              # 使用上面自定义的主键生成算法
              key-generator-name: snowflake


            # 配置分表策略
            table-strategy:
              standard:
                # 对应article表中自定义的字段
                sharding-column: id
                # 使用上面自定义的分片算法
                sharding-algorithm-name: article-strategy-inline

# print logs
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
    # 关闭数据库下划线自动转驼峰
    map-underscore-to-camel-case: false

4.3 Article

package com.mason.subtable.entity;

import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName("article")
public class Article {
    private Long id;
    private String title;
    private String summary;
    private String keywords;

    @TableField("create_time")
    private String create_time;
    @TableField("update_time")
    private String update_time;
}

4.4 ArticleMapper

package com.mason.subtable.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.mason.subtable.entity.Article;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface ArticleMapper extends BaseMapper<Article> {
}

4.5 DataService

package com.mason.subtable.service;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.mason.subtable.entity.Article;
import com.mason.subtable.mapper.ArticleMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;


import java.util.List;


@Service
public class DataService {

    @Autowired
    private ArticleMapper articleMapper;

    // 添加数据
    public int addMultiData(){
        // 批量添加数据
        Article article = new Article();
        article.setTitle("河南大学");
        article.setKeywords("河南,大学");
        article.setSummary("河南大学在开封");
        this.articleMapper.insert(article);

        article = new Article();
        article.setTitle("软件学院");
        article.setKeywords("河南,大学");
        article.setSummary("河南大学在开封");
        this.articleMapper.insert(article);

        article = new Article();
        article.setTitle("河南大学");
        article.setKeywords("软件,学院");
        article.setSummary("河南大学软件学院");
        this.articleMapper.insert(article);

        return 1;
    }

    // 获取数据
    public List<Article> getMultiData(){
        QueryWrapper<Article> wrapper = new QueryWrapper<>();
        wrapper.eq("title","河南大学");
        return this.articleMapper.selectList(wrapper);
    }

}

4.6 DataController

package com.mason.subtable.controller;


import com.mason.subtable.entity.Article;
import com.mason.subtable.service.DataService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;


@RestController
@RequestMapping("/data")
public class DataController {
    @Autowired
    private DataService dataService;

    @GetMapping("/add")
    public int addData(){
        return this.dataService.addMultiData();
    }

    @GetMapping("/query")
    public List<Article> queryData(){
        return this.dataService.getMultiData();
    }

}

4.7 SubtableApplication

package com.mason.subtable;


import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

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