CREATE TABLE `tb_user_0`  (
  `id` bigint(20) UNSIGNED NOT NULL AUTO_INCREMENT COMMENT '主鍵',
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '姓名',
  `sex` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '性別',
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

  <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.1</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>

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

@TableName(value = "tb_user")
public class User implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 主鍵，注意此處IdType必須是AUTO，不然框架就會自動生成id，分表時生成id的策略就不生效了
     */
    @TableId(value = "id", type = IdType.AUTO)
    private Long id;

    /**
     * 姓名
     */
    @TableField(value = "name")
    private String name;

    /**
     * 性別
     */
    @TableField(value = "sex")
    private String sex;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    @Override
    public String toString() {
        return "User{" +
            "id=" + id +
            ", name=" + name +
            ", sex=" + sex +
        "}";
    }
}

public interface UserMapper extends BaseMapper<User> {

}

spring:
  shardingsphere:
    datasource:
      # 數據源名稱，有幾個數據源就寫幾個，如果是分表，就會寫多個
      names: db0
      # 為每個數據源單獨配置，注意這里要跟上面寫的名稱一致
      db0:
        # 數據庫連接池實現(xiàn)類型，這里使用的是Hikari
        type: com.zaxxer.hikari.HikariDataSource
        # 數據庫驅動類，連接地址，用戶名，密碼等
        driver-class-name: com.mysql.cj.jdbc.Driver
        jdbc-url: jdbc:mysql://localhost:3306/sharding?useUnicode=true&characterEncoding=utf8&useSSL=false
        username: root
        password: 123456
    rules:
      sharding:
        tables:
          # 分表的表名，程序中對這張表的操作，都會采用下面的路由方案
          tb_user:
            # 這里是實際的數據節(jié)點信息，要把庫名和表名都寫全，這里也支持使用表達式，比如下面這張$->{0..9}
            actual-data-nodes: db0.tb_user_$->{0..9}
            # 配置分表策略
            table-strategy:
              # 這里選擇的標準策略，也可以配置復雜策略，或者也可以用代碼來實現(xiàn)
              standard:
                # 分片字段，這里是用用戶id作為分片字段
                sharding-column: id
                # 這里是我們自定義的分片算法名稱，后面會有實現(xiàn)方案
                sharding-algorithm-name: user-inline
            # 主鍵生成策略
            key-generate-strategy:
              # 生成主鍵算法的名稱
              key-generator-name: snowflake
              # 主鍵字段
              column: id
        # 自定義的主鍵算法
        key-generators:
          snowflake:
            # 使用雪花算法生成主鍵
            type: SNOWFLAKE
        # 自定義的分表算法
        sharding-algorithms:
          user-inline:
            #使用inline類型實現(xiàn)
            type: inline
            props:
              #分片表達式，用id對10取模，然后分散到10個表中
              algorithm-expression: tb_user_$->{id % 10}
    props:
      # 打印日志，方便我們觀察執(zhí)行的sql語句
      sql-show: true

@Autowired
    private UserMapper userMapper;

    @Test
    public void insertTest() {
        for (int i=0; i<100; i++) {
            User user = new User();
            user.setName("test" + i);
            user.setSex("男");
            userMapper.insert(user);
        }
    }

@Test
    public void selectByIdTest() {
        userMapper.selectById(1668501944537858050L);
    }

    @Test
    public void selectByNameTest() {
        QueryWrapper<User> qy = new QueryWrapper<>();
        qy.eq("name","test1");
        userMapper.selectList(qy);
    }

//分片字段數據類型是什么，這里泛型就寫什么
public class UserShardingAlgorithm implements StandardShardingAlgorithm<Long> {

    //精確分片算法實現(xiàn)，collection是實際表，也就是配置文件里的actual-data-nodes內容
    //preciseShardingValue對象包括邏輯表名，分表算法的字段和字段值
    @Override
    public String doSharding(Collection<String> collection, PreciseShardingValue<Long> preciseShardingValue) {
        //對分片字段也就是用戶id取模
        String suffix = String.valueOf(preciseShardingValue.getValue() % 10);
        //遍歷表名，找到符合要求的表，返回即可
        for (String tableName : collection) {
            if (tableName.endsWith(suffix)) {
                return tableName;
            }
        }
        throw new UnsupportedOperationException();
    }

    //范圍分片，我們暫不支持
    @Override
    public Collection<String> doSharding(Collection<String> collection, RangeShardingValue<Long> rangeShardingValue) {
        throw new UnsupportedOperationException();
    }
    
    //初始化信息接口
    @Override
    public void init() {

    }

    //分片算法類型
    @Override
    public String getType() {
        return "USER_SHARDING";
    }
}

        sharding-algorithms:
          user-inline:
            type: inline
            props:
              algorithm-expression: tb_user_$->{id % 10}

        sharding-algorithms:
          user-inline:
            type: class_based # 自定義類分片算法類型
            props:
              strategy: standard
              # 自定義算法類的路徑
              algorithmClassName: com.github.learn.sharding.algorithm.UserShardingAlgorithm

        key-generators:
          user-id-generator:
            type: SNOWFLAKE
            props:
              max-vibration-offset: 9
              worker-id: ${workerId}

@Configuration
public class WorkerIdConfig {

    private static final Logger LOGGER = LoggerFactory.getLogger(WorkerIdConfig.class);

    static {
        try {
            InetAddress address = InetAddress.getLocalHost();
            // IP地址byte[]數組形式，這個byte數組的長度是4，數組0~3下標對應的值分別是192，168，1，108
            byte[] ipAddressByteArray = address.getAddress();
            // workerId取ip地址后十位
            long workerId = ((ipAddressByteArray[ipAddressByteArray.length - 2] & 0x03) << 8) + (ipAddressByteArray[ipAddressByteArray.length - 1] & 0xFF);
            LOGGER.info("當前機器 workerId: {}", workerId);
            System.setProperty("workerId", String.valueOf(workerId));
        } catch (Exception e) {
            LOGGER.error("worker id failed:{}", e.getMessage(), e);
        }
    }
}