花了2天时间研究了一下Sharding-JDBC的使用，这里简单记录一下。
代码弄的比较乱，就没放到git上，需要源码的可以留下邮箱或者其他联系方式，我看到了发你。

遗留问题：Druid无法监控2个数据源的sql。
应该需要通过编写DataSourceConfig.java的方式解决。

目录
1.POM文件的内容
2.分库分表+分库不分表
3.读写分离
4.ComplexKeysShardingAlgorithm实现

1.POM文件的内容

pom文件在引用Sharding-jdbc时有2张方式：

sharding-jdbc-spring-boot-starter（后面的描述用的是这种方式）
这种方式可以不用自己写DataSourceConfig文件

sharding-jdbc-core
这种方式的例子，基本都是要自己写DataSourceConfig文件的
参考：//www.greatytc.com/p/3b2ab87b0de7
https://blog.csdn.net/a992795427/article/details/85102918
https://www.cnblogs.com/mr-yang-localhost/p/8280500.html

#sharding-jdbc-spring-boot-starter方式的参考pom文件
<dependencies>
  <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
  </dependency>
  <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.1.0</version>
  </dependency>
  <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.21</version>
  </dependency>

  <dependency>
      <groupId>io.shardingsphere</groupId>
      <artifactId>sharding-jdbc-spring-boot-starter</artifactId>
      <version>3.1.0.M1</version>
  </dependency>

  <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid-spring-boot-starter</artifactId>
      <version>1.1.23</version>
  </dependency>
</dependencies>

2.分库分表+分库不分表

用的的数据库

image.png

# 相关表结构
CREATE TABLE `order0` (
  `id` bigint(11) NOT NULL COMMENT '主键ID',
  `user_id` bigint(11) DEFAULT NULL COMMENT '用户ID',
  `order_id` bigint(11) DEFAULT NULL COMMENT '订单ID',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

 CREATE TABLE `user_info` (
  `user_id` bigint(19) NOT NULL,
  `user_name` varchar(45) DEFAULT NULL,
  `account` varchar(45) NOT NULL,
  `password` varchar(45) DEFAULT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

application.properties文件参考

spring.application.name=sharding-jdbc

#mybatis
mybatis.configuration.map-underscore-to-camel-case=true
mybatis.type-aliases-package=com.lbc.demo.model
mybatis.mapper-locations=classpath:mapper/*Mapper.xml

#当注册遇到相同名字是否允许被注册，在配置中心无效
spring.main.allow-bean-definition-overriding=true

#所有主从库
sharding.jdbc.datasource.names=user0,user1

#dsmaster0
sharding.jdbc.datasource.user0.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.user0.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.user0.url=jdbc:mysql://localhost:3306/user0?useSSL=false
sharding.jdbc.datasource.user0.username=root
sharding.jdbc.datasource.user0.password=password

#slave for ds_master_0
sharding.jdbc.datasource.user1.type=com.alibaba.druid.pool.DruidDataSource
sharding.jdbc.datasource.user1.driver-class-name=com.mysql.jdbc.Driver
sharding.jdbc.datasource.user1.url=jdbc:mysql://localhost:3306/user1?useSSL=false
sharding.jdbc.datasource.user1.username=root
sharding.jdbc.datasource.user1.password=password

#分库规则
sharding.jdbc.config.sharding.default-database-strategy.inline.sharding-column=user_id
sharding.jdbc.config.sharding.default-database-strategy.inline.algorithm-expression=user$->{user_id % 2}

# 绑定逻辑表
sharding.jdbc.config.sharding.binding-tables=order 
# 设置分表规则
# sharding.jdbc.config.sharding.tables.逻辑表.actual-data-nodes：逻辑表对应的真实表
# sharding.jdbc.config.sharding.tables.逻辑表.table-strategy.inline.sharding-column：分表列
# sharding.jdbc.config.sharding.tables.逻辑表.table-strategy.inline.algorithm-expression：分表算法
# sharding.jdbc.config.sharding.tables.逻辑表.key-generator-column-name：主键列
# 分库，也分表
sharding.jdbc.config.sharding.tables.order.actual-data-nodes=user$->{0..1}.order$->{0..1}
sharding.jdbc.config.sharding.tables.order.table-strategy.inline.sharding-column=order_id
sharding.jdbc.config.sharding.tables.order.table-strategy.inline.algorithm-expression=order$->{order_id % 2}
sharding.jdbc.config.sharding.tables.order.key-generator-column-name=id

# 只分库，不分表
sharding.jdbc.config.sharding.tables.user_info.actual-data-nodes=user$->{0..1}.user_info
sharding.jdbc.config.sharding.tables.user_info.table-strategy.inline.sharding-column=user_id
sharding.jdbc.config.sharding.tables.user_info.table-strategy.inline.algorithm-expression=user_info
sharding.jdbc.config.sharding.tables.user_info.key-generator-column-name = user_id

#逻辑主从库名和实际主从库映射关系
#sharding.jdbc.config.sharding.master-slave-rules.ds0.master-data-source-name=dsmaster0
#用逗号分隔
#sharding.jdbc.config.sharding.master-slave-rules.ds0.slave-data-source-names=dsmaster0
#sharding.jdbc.config.sharding.master-slave-rules.dsmaster1.masterDataSourceName=dsmaster1
#sharding.jdbc.config.sharding.master-slave-rules.dsmaster1.slaveDataSourceNames=dsmaster1slave0

server.port=8080

3.读写分离

用到的数据库和表机构同上
application.yml参考文件

sharding:
  jdbc:
    dataSource:
      names: db-test0,db-test1
      # 配置主库
      db-test0: #org.apache.tomcat.jdbc.pool.DataSource
        type: com.alibaba.druid.pool.DruidDataSource
        driverClassName: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/user0?useUnicode=true&characterEncoding=utf8&tinyInt1isBit=false&useSSL=false&serverTimezone=GMT
        username: root
        password: password
        #最大连接数
        maxPoolSize: 3
      db-test1: # 配置第一个从库
        type: com.alibaba.druid.pool.DruidDataSource
        driverClassName: com.mysql.jdbc.Driver
        url: jdbc:mysql://localhost:3306/user1?useUnicode=true&characterEncoding=UTF-8&allowMultiQueries=true&useSSL=false&serverTimezone=GMT
        username: root
        password: password
        maxPoolSize: 3

    config:
      masterslave: # 配置读写分离
        load-balance-algorithm-type: round_robin # 配置从库选择策略，提供轮询与随机，这里选择用轮询//random 随机 //round_robin 轮询
        name: db1s2
        master-data-source-name: db-test0
        slave-data-source-names: db-test1

    props:
      sql: # 开启SQL显示，默认值: false，注意：仅配置读写分离时不会打印日志！！！
        show: true

mybatis:
  configuration:
    map-underscore-to-camel-case: true
  type-aliases-package: com.lbc.demo.model
  mapper-locations: classpath:mapper/*Mapper.xml

4.ComplexKeysShardingAlgorithm实现
Complex方式的配置文件和2.分库分表+分库不分表的配置文件类似，只改了一个东西

分库，也分表

sharding.jdbc.config.sharding.tables.order.actual-data-nodes=user$->{0..1}.order$->{0..1}
sharding.jdbc.config.sharding.tables.order.table-strategy.complex.sharding-columns=user_id,order_id
sharding.jdbc.config.sharding.tables.order.table-strategy.complex.algorithm-class-name=com.lbc.demo.config.ComplexShardingAlgorithm

然后，需要增加一个路由类ComplexShardingAlgorithm，这里最好debug一下。

public class ComplexShardingAlgorithm implements ComplexKeysShardingAlgorithm {
/**
 * @param collection     在加载配置文件时，会解析表分片规则。将结果存储到 collection中，doSharding（）参数使用
 * @param shardingValues SQL中对应的
 * @return
 */
@Override
public Collection<String> doSharding(Collection<String> collection, Collection<ShardingValue> shardingValues) {
    System.out.println("collection:" + collection + ",shardingValues:" + shardingValues);

    Collection<Long> orderIdValues = getShardingValue(shardingValues, "order_id");
    Collection<Long> userIdValues = getShardingValue(shardingValues, "user_id");

    List<String> shardingSuffix = new ArrayList<>();

    // user_id，order_id分片键进行分表
    for (Long userId : userIdValues) {
        for (Long orderId : orderIdValues) {
            String suffix = userId % 2 + "_" + orderId % 2;
            //写死测试
            suffix="0";
            for (String s : collection) {
                if (s.endsWith(suffix)) {
                    shardingSuffix.add(s);
                }
            }
        }
    }

    return shardingSuffix;
}

private Collection<Long> getShardingValue(Collection<ShardingValue> shardingValues, final String key) {
    Collection<Long> valueSet = new ArrayList<>();
    Iterator<ShardingValue> iterator = shardingValues.iterator();
    while (iterator.hasNext()) {
        ShardingValue next = iterator.next();
        if (next instanceof ListShardingValue) {
            ListShardingValue value = (ListShardingValue) next;
            // user_id，order_id分片键进行分表
            if (value.getColumnName().equals(key)) {
                return value.getValues();
            }
        }
    }
    return valueSet;
}
}

参考了太多了，记不清了：
//www.greatytc.com/p/3b2ab87b0de7
//www.greatytc.com/p/9eebfae039c9
https://segmentfault.com/a/1190000019906637
https://www.cnblogs.com/yixinjishu/p/10876071.html
https://www.cnblogs.com/mr-yang-localhost/p/8280500.html
[https://blog.csdn.net/hy245120020/article/details/85335446]
//www.greatytc.com/p/e4f291052c83
(https://blog.csdn.net/hy245120020/article/details/85335446)
https://blog.csdn.net/forezp/article/details/94343671
https://blog.csdn.net/a992795427/article/details/85102918
https://www.cnblogs.com/mr-yang-localhost/p/8280500.html

SpringBoot 2.3 整合最新版 ShardingJdbc + Druid + MyBatis 实现分库分表

SpringBoot+Mybatis+Sharding-JDBC