ShardingJdbc分库分表+连表查询(超简单)

下载依赖

这边建议所有的依赖版本都和我同步，因为我被版本冲突折磨了好久...

    
        org.springframework.boot
        spring-boot-starter-parent
        2.2.1.RELEASE
         
    



    

        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.springframework.boot
            spring-boot-starter
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
            
                
                    org.junit.vintage
                    junit-vintage-engine
                
            
        

        
        
            com.alibaba
            druid
            1.1.20
        

        
        
            mysql
            mysql-connector-java
            8.0.23 
        

        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.0.5
        

        
        
            org.apache.shardingsphere
            sharding-jdbc-spring-boot-starter
            4.0.0-RC1
        

        
        
            org.projectlombok
            lombok
            1.18.22 
        




        
            javax.xml.bind
            jaxb-api
            2.3.1
        
        
            com.sun.xml.bind
            jaxb-core
            2.3.0
        
        
            com.sun.xml.bind
            jaxb-impl
            2.3.2
        
        

    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
            
            
                org.apache.maven.plugins
                maven-compiler-plugin
                
                    1.8
                    1.8
                
            
        
    

创建数据库

CREATE TABLE `demo_order_0`  (
  `user_id` int(0) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `activity_id` int(0) NULL DEFAULT NULL
)

CREATE TABLE `demo_activity_0`  (
  `id` int(0) NOT NULL,
  `type` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL COMMENT '类型',
  `acticity_id` int(0) NULL DEFAULT NULL COMMENT '关联id',
  PRIMARY KEY (`id`) USING BTREE
) 

我只给了两张表，其他的表名用这个sql改一下表名即可，测试数据自行插入，两张表的activity_id字段是关联字段(后面做连表查询)

添加配置文件

application.properties

# 配置Sharding-JDBC的分片策略
# 配置数据源，给数据源起名g1,g2...此处可配置多数据源
spring.shardingsphere.datasource.names=g1,g2

# 配置允许一个实体类映射多张表
spring.main.allow-bean-definition-overriding=true

# 配置数据源具体内容————————包含  连接池，  驱动，             地址，   用户名，    密码
#                                 g1配置g1.type,g1.driver-class-name,g1.url,g1.username,g1.password
spring.shardingsphere.datasource.g1.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.g1.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.g1.url=jdbc:mysql://127.0.0.1:3306/ams_sharding_order_0?characterEncoding=utf-8&useUnicode=true&useSSL=false&serverTimezone=UTC
spring.shardingsphere.datasource.g1.username=root
spring.shardingsphere.datasource.g1.password=root

# 配置数据源具体内容————————包含  连接池，  驱动，             地址，   用户名，    密码
#                                 g2配置g2.type,g2.driver-class-name,g2.url,g2.username,g2.password
spring.shardingsphere.datasource.g2.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.g2.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.g2.url=jdbc:mysql://127.0.0.1:3306/ams_sharding_order_1?characterEncoding=utf-8&useUnicode=true&useSSL=false&serverTimezone=UTC
spring.shardingsphere.datasource.g2.username=root
spring.shardingsphere.datasource.g2.password=root

# 配置数据库的分布，表的分布
# m1:goods_1 goods_2; m2:goods_1,goods_2;
spring.shardingsphere.sharding.tables.demo_order.actual-data-nodes=g$->{1..2}.demo_order_$->{0..1}

# 指定goods表 主键gid 生成策略为 SNOWFLAKE
#spring.shardingsphere.sharding.tables.goods.key-generator.column=gid
#spring.shardingsphere.sharding.tables.goods.key-generator.type=SNOWFLAKE

# 指定数据库分片策略 约定user_id值是偶数添加到goods_db_1中，奇数添加到goods_db_2中
spring.shardingsphere.sharding.tables.demo_order.database-strategy.inline.sharding-column=user_id
spring.shardingsphere.sharding.tables.demo_order.database-strategy.inline.algorithm-expression=g$->{user_id % 2 +1}

# 指定表分片策略 约定gid值是偶数添加到goods_1表，如果gid是奇数添加到goods_2表
spring.shardingsphere.sharding.tables.demo_order.table-strategy.inline.sharding-column=activity_id
spring.shardingsphere.sharding.tables.demo_order.table-strategy.inline.algorithm-expression=demo_order_$->{activity_id % 2 }

# 配置新的表 demo_activity 的分片规则
spring.shardingsphere.sharding.tables.demo_activity.actual-data-nodes=g$->{1..2}.demo_activity_$->{0..1}

# 指定数据库分片策略 约定activity_id值是偶数添加到g1中，奇数添加到g2中
spring.shardingsphere.sharding.tables.demo_activity.database-strategy.inline.sharding-column=activity_id
spring.shardingsphere.sharding.tables.demo_activity.database-strategy.inline.algorithm-expression=g$->{activity_id % 2 +1}

# 指定表分片策略 约定activity_id值是偶数添加到demo_activity_0表，如果是奇数添加到demo_activity_1表
spring.shardingsphere.sharding.tables.demo_activity.table-strategy.inline.sharding-column=activity_id
spring.shardingsphere.sharding.tables.demo_activity.table-strategy.inline.algorithm-expression=demo_activity_$->{activity_id % 2 }
#加入连接表配置
spring.shardingsphere.sharding.binding-tables=demo_order,demo_activity
# 打开sql输出日志
spring.shardingsphere.props.sql.show=true

注意：数据库的表名一定要和我一致，不然就要修改配置中的分库分表策略，不然会启动失败

创建实体类

@TableName("demo_order")
@Data
public class DemoOrder {

    @TableField(value = "user_id")
    private Long userId;

    @TableField(value = "name")
    private String name;

    @TableField(value = "activity_id")
    private Long activityId;
}




@Data
public class OrderActivity {


 private Long userId;

 private String name;

 private Long activityId;

 private Long id;

 private String type;
}

创建Controller

@RequestMapping("/order")
@RestController
public class OrderController {

 @Resource
 private OrderMapper orderMapper;

 @PostMapping("/save")
 public void save(@RequestBody DemoOrder demoOrder){

  orderMapper.insert(demoOrder);

 }

 @PostMapping("/list")
 public List list(){

  return orderMapper.selectList(null);
 }

 @PostMapping("/orderList")
 public List orderList(){


  return orderMapper.orderList();
 }

创建mapper

@Mapper
public interface OrderMapper extends BaseMapper {

    @Select(
            "SELECT * " +
                    " FROM demo_order o " +
                    " LEFT JOIN demo_activity a " +
                    " ON o.activity_id = a.activity_id "
    )
    List orderList();
}

测试

新增数据(分库分表)

可以通过日志发现数据插入到了 g1 数据源的demo_order_0表中

可以看到数据已经插入

列表

通过列表的日志可以发现他是查询了所有表的数据汇总，如果要做分页按之前的样式写就可以了

列表(关联查询)

可以看到关联的类型已经查出