1 分表分库
LogicTable
数据分片的逻辑表,对于水平拆分的数据库(表),同一类表的总称。
订单信息表拆分为2张表,分别是t_order_0、t_order_1,他们的逻辑表名为t_order。
ActualTable
在分片的数据库中真实存在的物理表。即上个示例中的t_order_0、t_order_1。
DataNode
数据分片的最小单元。由数据源名称和数据表组成,例:test_msg0.t_order_0。配置时默认各个分片数据库的表结构均相同,直接配置逻辑表和真实表对应关系即可。
ShardingColumn
分片字段。用于将数据库(表)水平拆分的关键字段。SQL中如果无分片字段,将执行全路由,性能较差。Sharding-JDBC支持多分片字段。
ShardingAlgorithm
分片算法。Sharding-JDBC通过分片算法将数据分片,支持通过等号、BETWEEN和IN分片。分片算法目前需要业务方开发者自行实现,可实现的灵活度非常高。未来Sharding-JDBC也将会实现常用分片算法,如range,hash和tag等。
2 自定义分片模式
2.1 数据库表结构
创建ds_0数据库,新建表如下:
CREATE TABLE `t_order_0` (
`order_id` bigint(20) NOT NULL,
`user_id` bigint(20) NOT NULL,
PRIMARY KEY (`order_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
CREATE TABLE `t_order_1` (
`order_id` bigint(20) NOT NULL,
`user_id` bigint(20) NOT NULL,
PRIMARY KEY (`order_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin;
3 新建maven项目
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.3.RELEASE</version>
<relativePath /> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!-- jpa -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.3.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<!-- 引入shardingjdbc依赖信息 -->
<dependency>
<groupId>io.shardingjdbc</groupId>
<artifactId>sharding-jdbc-core</artifactId>
<version>2.0.3</version>
</dependency>
<dependency>
<groupId>com.dangdang</groupId>
<artifactId>sharding-jdbc-self-id-generator</artifactId>
<version>1.4.2</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.0.12</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
4 application配置
###数据库访问连接
spring:
jdbc:
db0:
password: 123456
className: com.mysql.jdbc.Driver
url: jdbc:mysql://192.168.222.157:3306/%s?characterEncoding=utf-8
username: root
jpa:
database: mysql
show-sql: true
hibernate:
## 自己建表
ddl-auto: none
application:
name: sharding-jdbc-first
5 配置分表算法
5.1 配置数据库连接
package com.example.demo.config;
import com.alibaba.druid.pool.DruidDataSource;
import com.dangdang.ddframe.rdb.sharding.api.ShardingDataSourceFactory;
import com.dangdang.ddframe.rdb.sharding.api.rule.DataSourceRule;
import com.dangdang.ddframe.rdb.sharding.api.rule.ShardingRule;
import com.dangdang.ddframe.rdb.sharding.api.rule.TableRule;
import com.dangdang.ddframe.rdb.sharding.api.strategy.table.TableShardingStrategy;
import com.dangdang.ddframe.rdb.sharding.id.generator.IdGenerator;
import com.dangdang.ddframe.rdb.sharding.id.generator.self.CommonSelfIdGenerator;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.sql.DataSource;
import java.util.Arrays;
import java.util.HashMap;
import java.util.Map;
// 数据源相关配置信息
@Configuration
public class DataSourceConfig {
@Value("${spring.jdbc.db0.className}")
private String className;
@Value("${spring.jdbc.db0.url}")
private String url;
@Value("${spring.jdbc.db0.username}")
private String username;
@Value("${spring.jdbc.db0.password}")
private String password;
@Bean
public IdGenerator getIdGenerator() {
return new CommonSelfIdGenerator();
}
@Bean
public DataSource getDataSource() {
return buildDataSource();
}
private DataSource buildDataSource() {
// 1.设置分库映射
Map<String, DataSource> dataSourceMap = new HashMap<>(2);
dataSourceMap.put("ds_0", createDataSource("ds_0"));
// dataSourceMap.put("ds_1", createDataSource("ds_1"));
// 设置默认db为ds_0,也就是为那些没有配置分库分表策略的指定的默认库
// 如果只有一个库,也就是不需要分库的话,map里只放一个映射就行了,只有一个库时不需要指定默认库,
// 但2个及以上时必须指定默认库,否则那些没有配置策略的表将无法操作数据
DataSourceRule rule = new DataSourceRule(dataSourceMap, "ds_0");
// 2.设置分表映射,将t_order_0和t_order_1两个实际的表映射到t_order逻辑表
TableRule orderTableRule = TableRule.builder("t_order").actualTables(Arrays.asList("t_order_0", "t_order_1"))
.dataSourceRule(rule).build();
// 3.具体的分库分表策略
ShardingRule shardingRule = ShardingRule.builder().dataSourceRule(rule)
.tableRules(Arrays.asList(orderTableRule))
// 根据userid分片字段
.tableShardingStrategy(new TableShardingStrategy("user_id", new TableShardingAlgorithm())).build();
// 创建数据源
DataSource dataSource = ShardingDataSourceFactory.createDataSource(shardingRule);
return dataSource;
}
private DataSource createDataSource(String dataSourceName) {
// 使用druid连接数据库
DruidDataSource druidDataSource = new DruidDataSource();
druidDataSource.setDriverClassName(className);
druidDataSource.setUrl(String.format(url, dataSourceName));
druidDataSource.setUsername(username);
druidDataSource.setPassword(password);
return druidDataSource;
}
}
5.2 配置分表策略
分表算法类需要实现SingleKeyTableShardingAlgorithm<T>接口
package com.example.demo.config;
import com.dangdang.ddframe.rdb.sharding.api.ShardingValue;
import com.dangdang.ddframe.rdb.sharding.api.strategy.table.SingleKeyTableShardingAlgorithm;
import java.util.Collection;
// 表分片算法
public class TableShardingAlgorithm implements SingleKeyTableShardingAlgorithm<Long> {
// sql 中关键字 匹配符为 =的时候,表的路由函数
public String doEqualSharding(Collection<String> availableTargetNames, ShardingValue<Long> shardingValue) {
for (String tableName : availableTargetNames) {
if (tableName.endsWith(shardingValue.getValue() % 2 + "")) {
return tableName;
}
}
throw new IllegalArgumentException();
}
@Override
public Collection<String> doInSharding(Collection<String> availableTargetNames, ShardingValue<Long> shardingValue) {
return null;
}
@Override
public Collection<String> doBetweenSharding(Collection<String> availableTargetNames,
ShardingValue<Long> shardingValue) {
return null;
}
}
6 新建实体类
package com.example.demo.entity;
import lombok.Data;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;
@Data
@Entity
@Table(name = "t_order")
public class OrderEntity {
@Id
private Long orderId;
private Long userId;
}
7 OrderRepository
package com.example.demo.repository;
import com.example.demo.entity.OrderEntity;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import java.util.List;
public interface OrderRepository extends CrudRepository<OrderEntity, Long> {
@Query(value = "SELECT order_id ,user_id FROM t_order where order_id in (?1);", nativeQuery = true)
public List<OrderEntity> findExpiredOrderState(List<String> bpIds);
}
8 OrderController
package com.example.demo.controller;
import com.example.demo.entity.OrderEntity;
import com.example.demo.repository.OrderRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.ArrayList;
import java.util.List;
@RestController
public class OrderController {
@Autowired
private OrderRepository orderRepository;
// 查询所有的订单信息
@RequestMapping("/getOrderAll")
public List<OrderEntity> getOrderAll() {
return (List<OrderEntity>) orderRepository.findAll();
}
// 使用in条件查询
@RequestMapping("/inOrder")
public List<OrderEntity> inOrder() {
List<String> ids = new ArrayList<>();
ids.add("2");
ids.add("3");
ids.add("4");
ids.add("5");
return orderRepository.findExpiredOrderState(ids);
}
// 增加
@RequestMapping("/inserOrder")
public String inserOrder(OrderEntity orderEntity) {
for (int i = 0; i < 10; i++) {
OrderEntity order = new OrderEntity();
order.setOrderId((long) i);
order.setUserId((long) i);
orderRepository.save(order);
}
return "success";
}
}
9 新建启动类
package com.example.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
@SpringBootApplication
@EnableJpaRepositories(basePackages = "com.example.demo.repository")
public class AppSharding {
public static void main(String[] args) {
SpringApplication.run(AppSharding.class, args);
}
}
10 启动项目
访问http://localhost:8080/inserOrder
查看数据库
分表测试成功