ShardingSphere-JDBC入门

Posted 2021-08-07 G_whang

ShardingSphere-JDBC

简介：
ShardingSphere-JDBC 是 Apache ShardingSphere 的第一个产品，也是 Apache ShardingSphere 的前身。 定位为轻量级 Java 框架，在 Java 的 JDBC 层提供的额外服务。 它使用客户端直连数据库，以 jar 包形式提供服务，无需额外部署和依赖，可理解为增强版的 JDBC 驱动，完全兼容 JDBC 和各种 ORM 框架。

• 适用于任何基于 JDBC 的 ORM 框架，如：JPA, Hibernate, Mybatis, Spring JDBC Template 或直接使用 JDBC。
• 支持任何第三方的数据库连接池，如：DBCP, C3P0, BoneCP, Druid, HikariCP 等。
• 支持任意实现 JDBC 规范的数据库，目前支持 mysql，Oracle，SQLServer，PostgreSQL 以及任何遵循 SQL92 标准的数据库。

springBoot使用ShardingSphere-JDBC 进行数据库分表
新建数据库表：
t_user0，t_user1 除了表的名字不一致，其他均为一致的

CREATE TABLE `t_user0` (
  `id` bigint NOT NULL,
  `name` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '名称',
  `city_id` int DEFAULT NULL COMMENT '城市',
  `sex` tinyint(1) DEFAULT NULL COMMENT '性别',
  `phone` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '电话',
  `email` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '邮箱',
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '创建时间',
  `password` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '密码',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 ROW_FORMAT=DYNAMIC;


CREATE TABLE `t_user1` (
  `id` bigint NOT NULL,
  `name` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '名称',
  `city_id` int DEFAULT NULL COMMENT '城市',
  `sex` tinyint(1) DEFAULT NULL COMMENT '性别',
  `phone` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '电话',
  `email` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '邮箱',
  `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '创建时间',
  `password` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '密码',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 ROW_FORMAT=DYNAMIC;

代码如下：
pom

<?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>2.1.4.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>shatding-springboot-mybatis-generator01</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>shatding-springboot-mybatis-generator01</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>1.8</java.version>
        <sharding.jdbc.version>3.0.0</sharding.jdbc.version>
        <mybatis.version>1.3.0</mybatis.version>
        <druid.version>1.1.10</druid.version>
        <mysql.version>8.0.19</mysql.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>${mybatis.version}</version>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>${druid.version}</version>
        </dependency>
        <dependency>
            <groupId>io.shardingsphere</groupId>
            <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
            <version>${sharding.jdbc.version}</version>
        </dependency>

        <!-- 引入Lombok -->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>

    </dependencies>

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

</project>

实体类

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

import java.util.Date;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {

    private Long id;
    private String name;
    private String phone;
    private String email;
    private String password;
    private Integer cityId;
    private Date createTime;
    private Integer sex;

}

controller

import com.example.shatdingspringbootmybatisgenerator01.entity.User;
import com.example.shatdingspringbootmybatisgenerator01.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.Date;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/save")
    public String save(){
        for (int i = 0; i <10 ; i++) {
            User user=new User();
            user.setName("test"+i);
            user.setCityId(1%2==0?1:2);
            user.setCreateTime(new Date());
            // 1 男 2 女
            user.setSex(i%2==0?1:2);
            user.setPhone("11111111"+i);
            user.setEmail("xxxxx");
            user.setCreateTime(new Date());
            user.setPassword("eeeeeeeeeeee");
            userService.save(user);
        }
        return "success";
    }

    @RequestMapping("/get")
    public User get(Long id){
        User user = this.userService.get(id);
        return user;
    }

}

service

import com.example.shatdingspringbootmybatisgenerator01.entity.User;
import com.example.shatdingspringbootmybatisgenerator01.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public void save(User user){
        this.userMapper.save(user);
    }

    public User get(Long id){
        User user = this.userMapper.get(id);
        return user;
    }


}

mapper

import com.example.shatdingspringbootmybatisgenerator01.entity.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper {

    /**
     * 保存
     */
    void save(User user);

    /**
     * 查询
     * @param id
     * @return
     */
    User get(Long id);

}

mapper.xml

<?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.example.shatdingspringbootmybatisgenerator01.mapper.UserMapper">
    <insert id="save" parameterType="com.example.shatdingspringbootmybatisgenerator01.entity.User">
        INSERT INTO t_user(name,phone,email,city_id,sex,password)
        VALUES
        (
            #{name},#{phone},#{email},#{cityId},#{sex},#{password}
        )
    </insert>

    <select id="get" parameterType="long" resultType="com.example.shatdingspringbootmybatisgenerator01.entity.User">
        select * from t_user where id = #{id}
    </select>
</mapper>

配置文件

server:
  port: 8080
spring:
  application:
    name: shatding-springboot-mybatis
mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.example.shatdingspringbootmybatisgenerator.entity

# 官网 https://shardingsphere.apache.org/document/current/cn/user-manual/shardingsphere-jdbc/usage/sharding/yaml/
sharding:
  jdbc:
    datasource:
      names: ds0
      # 数据源ds0
      ds0:
        type: com.alibaba.druid.pool.DruidDataSource
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://127.0.0.1:3306/test_01?useSSL=false&serverTimezone=UTC
        username: root
        password: root
    config:
      sharding:
        props:
          sql.show: true
        tables:
          t_user:  #t_user表
            key-generator-column-name: id  #主键
            actual-data-nodes: ds0.t_user${0..1}    #数据节点,均匀分布
            table-strategy:  #分表策略
              inline: #行表达式
                sharding-column: sex
                algorithm-expression: t_user${sex % 2}  #按模运算分配

运行项目
访问http://localhost:8080/user/save
查看数据库
分表规则示按照性别来分表的 test0表插入的都是性别为女（2）的

test1

数据已经分表成功
然后访问：http://localhost:8080/user/get?id=620969081545162752

访问男用户数据：

查看后台打印SQL

如果对一张表进行分表，然后查询的时候，他实际上查询的是2张表，然后把查到的结果返回