java：使用shardingSphere访问mysql的分库分表数据

# 创建分库与分表

创建两个数据库【order_db_1、order_db_2】。
然后在两个数据库下分别创建三个表【orders_1、orders_2、orders_3】。
建表sql请参考：

CREATE TABLE `orders_1`  (`id` bigint NOT NULL,`order_type` varchar(255) NULL DEFAULT NULL,`customer_id` bigint NULL DEFAULT NULL,`amount` double NULL DEFAULT NULL,PRIMARY KEY (`id`) USING BTREE
) 
ENGINE = InnoDB

# 下面开始写测试代码：

【pom.xml】

<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><version>2.3.12.RELEASE</version>
</dependency>
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-actuator</artifactId><version>2.3.12.RELEASE</version>
</dependency>
<dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.2.0</version>
</dependency>
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>3.4.3.1</version>
</dependency>
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-core</artifactId><version>3.4.3.1</version>
</dependency>
<dependency><groupId>org.apache.shardingsphere</groupId><artifactId>sharding-jdbc-spring-boot-starter</artifactId><version>4.1.1</version>
</dependency>
<dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.22</version>
</dependency>
<dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><version>8.3.0</version>
</dependency>
<dependency><groupId>com.alibaba.fastjson2</groupId><artifactId>fastjson2</artifactId><version>2.0.49</version>
</dependency>

【application.properties】

server.port=8080
spring.application.name=myShardingSpheremanagement.server.port=8080
management.endpoints.web.exposure.include=*########################################management.health.db.enabled=false
management.health.elasticsearch.enabled=falsemybatis-plus.mapper-locations=classpath:mapper/*.xml
mybatis-plus.type-aliases-package=test/persistence/mapper##########################################################spring.shardingsphere.datasource.names=ds-order-db-1, ds-order-db-2######################################################
# 数据源spring.shardingsphere.datasource.ds-order-db-1.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.ds-order-db-1.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds-order-db-1.url=jdbc:mysql://192.168.44.228:3306/order_db_1
spring.shardingsphere.datasource.ds-order-db-1.username=root
spring.shardingsphere.datasource.ds-order-db-1.password=rootspring.shardingsphere.datasource.ds-order-db-2.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.ds-order-db-2.driver-class-name=com.mysql.jdbc.Driver
spring.shardingsphere.datasource.ds-order-db-2.url=jdbc:mysql://192.168.44.228:3306/order_db_2
spring.shardingsphere.datasource.ds-order-db-2.username=root
spring.shardingsphere.datasource.ds-order-db-2.password=root#################################################
# tablespring.shardingsphere.sharding.tables.orders.actual-data-nodes=ds-order-db-${1..2}.orders_${1..3}spring.shardingsphere.sharding.tables.orders.database-strategy.inline.sharding-column=customer_id
spring.shardingsphere.sharding.tables.orders.database-strategy.inline.algorithm-expression=ds-order-db-$->{customer_id % 2 + 1}spring.shardingsphere.sharding.tables.orders.table-strategy.inline.sharding-column=customer_id
spring.shardingsphere.sharding.tables.orders.table-strategy.inline.algorithm-expression=orders_${customer_id % 3 + 1}##################################################spring.shardingsphere.props.sql.show=true################################################

【mapper/OrdersMapper.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.chz.myShardingSphere.persistence.mapper.OrdersMapper"><resultMap id="orders" type="com.chz.myShardingSphere.persistence.po.Orders"><id column="id" property="id" /><result column="orderType" property="order_type" /><result column="customerId" property="customer_id" /><result column="amount" property="amount" /></resultMap><select id="testSelectOrder" parameterType="long" resultMap="orders">SELECT *FROM orders<where><if test="customerId!=null">and customer_id = #{customerId}</if></where>order by idLIMIT 10 OFFSET 0</select></mapper>

【TestController.java】

package com.chz.myShardingSphere.controller;@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {@Value("${spring.application.name}")private String applicationName;@Autowiredprivate TestService testService;@GetMapping("/testAddOrder")public String testAddOrder(@RequestParam(value = "id", defaultValue = "1") Long id) {testService.testAddOrder(id);return "testAddOrder";}@GetMapping("/testSelectOrder")public String testSelectOrder(@RequestParam(value = "customerId", required = false) Long customerId) {List<Orders> orders = testService.testSelectOrder(customerId);return JSON.toJSONString(orders);}@GetMapping("/testDeleteOrder")public String testDeleteOrder() {testService.testDeleteOrder();return "success";}
}

【OrdersMapper.java】

package com.chz.myShardingSphere.persistence.mapper;@Repository
@Mapper
public interface OrdersMapper extends BaseMapper<Orders>
{List<Orders> testSelectOrder(@Param("customerId") Long customerId);
}

【Orders.java】

package com.chz.myShardingSphere.persistence.po;@Getter
@Setter
public class Orders {private Long id;private Long orderType;private Long customerId;private Double amount;@Overridepublic String toString() {return "Orders{" +"id=" + id +", orderType=" + orderType +", customerId=" + customerId +", amount=" + amount +'}';}
}

【TestService.java】

package com.chz.myShardingSphere.server;@Service
public class TestService {@Autowiredprivate OrdersMapper ordersMapper;@Transactionalpublic void testAddOrder(long id){Orders orders = new Orders();orders.setId(id);orders.setCustomerId(id);orders.setOrderType(id);orders.setAmount((double)id);ordersMapper.insert(orders);}@Transactionalpublic List<Orders> testSelectOrder(Long customerId){List<Orders> orders = ordersMapper.testSelectOrder(customerId);return orders;}@Transactionalpublic void testDeleteOrder(){LambdaQueryWrapper<Orders> queryWrapper = new LambdaQueryWrapper<>();ordersMapper.delete(queryWrapper);}
}

【MyShardingSphereTest.java】

package com.chz.myShardingSphere;@SpringBootApplication
public class MyShardingSphereTest {public static void main(String[] args) {SpringApplication.run(MyShardingSphereTest.class, args);}
}

启动【MyShardingSphereTest】

# 下面进行测试：

访问以下url创建6条数据：

http://localhost:8080/test/testAddOrder?id=1
http://localhost:8080/test/testAddOrder?id=2
http://localhost:8080/test/testAddOrder?id=3
http://localhost:8080/test/testAddOrder?id=4
http://localhost:8080/test/testAddOrder?id=5
http://localhost:8080/test/testAddOrder?id=6

然后访问【http://localhost:8080/test/testSelectOrder】看下数据能不能查出来：

可以看到数据都查出来了。

增加个条件试试，访问【http://localhost:8080/test/testSelectOrder?customerId=1】

也运行正常