配置广播表

之前说过，所谓广播表其实就是一种配置表或字典表，这种表数据量不大，但很多地方都需要。

先创建一张配置表。

-- 依次在`itechthink_order_0`、`itechthink_order_1`和`itechthink_order_2`中执行以下建表语句
> DROP TABLE IF EXISTS t_config;
> CREATE TABLE t_config (
      id BIGINT(20) NOT NULL COMMENT '配置编码',
      ckey VARCHAR(512) DEFAULT NULL COMMENT '配置key',
      cvalue VARCHAR(512) DEFAULT NULL COMMENT '配置value',
      type VARCHAR(128) DEFAULT NULL COMMENT '配置类型',
      PRIMARY KEY (id)
  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT '配置表';

然后增加对应的实体类Config。

package com.itechthink.model;

import com.baomidou.mybatisplus.annotation.TableName;
import java.util.Date;
import java.util.Objects;

// 指定逻辑表名
@TableName("t_config")
public class Config {
    private Long id;

    private String ckey;

    private String cvalue;

    private String type;

    public Long getId() {
        return id;
    }

    public void setId(Long id) {
        this.id = id;
    }

    public String getCkey() {
        return ckey;
    }

    public void setCkey(String ckey) {
        this.ckey = ckey;
    }

    public String getCvalue() {
        return cvalue;
    }

    public void setCvalue(String cvalue) {
        this.cvalue = cvalue;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) return true;
        if (o == null || getClass() != o.getClass()) return false;
        Config config = (Config) o;
        return Objects.equals(id, config.id) && Objects.equals(ckey, config.ckey) && Objects.equals(cvalue, config.cvalue) && Objects.equals(type, config.type);
    }

    @Override
    public int hashCode() {
        return Objects.hash(id, ckey, cvalue, type);
    }

    @Override
    public String toString() {
        return "Config{" +
                "id=" + id +
                ", ckey='" + ckey + '\'' +
                ", cvalue='" + cvalue + '\'' +
                ", type='" + type + '\'' +
                '}';
    }
}

和之前的Order一样，也需要给Config实体类配上相应的mapper。

package com.itechthink.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.itechthink.model.Config;

public interface ConfigMapper extends BaseMapper<Config> {
}

接着修改配置文件application.properties，加入如下内容（其他地方不用修改）。

......

# 配置广播表，如果有多个表用,分隔
spring.shardingsphere.sharding.broadcast-tables=t_config
spring.shardingsphere.sharding.tables.t_config.key-generator.column=id
spring.shardingsphere.sharding.tables.t_config.key-generator.type=SNOWFLAKE

......

最后修改ShardingJDBCTest测试类。

package com.itechthink;

import com.itechthink.mapper.ConfigMapper;
import com.itechthink.mapper.OrderMapper;
import com.itechthink.model.Config;
import com.itechthink.model.Order;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import java.util.Date;
import java.util.UUID;

@RunWith(SpringRunner.class)
@SpringBootTest(classes = ShardingJDBCApplication.class)
public class ShardingJDBCTest {
    @Autowired
    private OrderMapper orderMapper;

    @Autowired
    private ConfigMapper configMapper;

    @Test
    public void testSaveOrder() {
        for (int i = 0; i < 10; i++) {
            Order order = new Order();
            // 分片键
            order.setUserid(Long.valueOf(i));
            order.setTradeno(UUID.randomUUID().toString().substring(0, 32).replaceAll("-", ""));
            order.setState(1);
            order.setMoney(168.00);
            order.setCreatetime(new Date());
            orderMapper.insert(order);
        }
    }

    @Test
    public void testSaveConfig(){
        Config config = new Config();
        config.setCkey("url");
        config.setCvalue("itechthink.com");
        config.setType("网站");
        configMapper.insert(config);
    }
}

执行后发现，itechthink_order_0、itechthink_order_1和itechthink_order_2这三个数据库的t_config表中都多了一条同样的数据。

> SELECT * FROM t_config;
+---------------------+------+----------------+--------+
| id                  | ckey | cvalue         | type   |
+---------------------+------+----------------+--------+
| 1822937004065742850 | url  | itechthink.com | 网站   |
+---------------------+------+----------------+--------+
1 row in set (0.00 sec)

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感谢支持

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