1. 简介
Sharding是一个简单的分库分表中间件，它不需要依赖于其他的服务，即可快速应用在实际项目的分库分表策略中。
2. 初始化数据库（db0、db1、db2）
1 #创建数据库db0 2 CREATE DATABASE IF NOT EXISTS `db0` DEFAULT CHARACTER SET utf8; 3 4 USE `db0`; 5 6 DROP TABLE IF EXISTS `t_user_0`; 7 CREATE TABLE `t_user_0` ( 8 `id` int(11) NOT NULL, 9 `username` varchar(255) DEFAULT NULL, 10 `org_code` int(11) DEFAULT NULL, 11 PRIMARY KEY (`id`) 12 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 13 14 DROP TABLE IF EXISTS `t_user_1`; 15 CREATE TABLE `t_user_1` ( 16 `id` int(11) NOT NULL, 17 `username` varchar(255) DEFAULT NULL, 18 `org_code` int(11) DEFAULT NULL, 19 PRIMARY KEY (`id`) 20 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 21 22 DROP TABLE IF EXISTS `t_user_2`; 23 CREATE TABLE `t_user_2` ( 24 `id` int(11) NOT NULL, 25 `username` varchar(255) DEFAULT NULL, 26 `org_code` int(11) DEFAULT NULL, 27 PRIMARY KEY (`id`) 28 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 29 30 #创建数据库db1 31 CREATE DATABASE IF NOT EXISTS `db1` DEFAULT CHARACTER SET utf8 ; 32 33 USE `db1`; 34 35 DROP TABLE IF EXISTS `t_user_0`; 36 CREATE TABLE `t_user_0` ( 37 `id` int(11) NOT NULL, 38 `username` varchar(255) DEFAULT NULL, 39 `org_code` int(11) DEFAULT NULL, 40 PRIMARY KEY (`id`) 41 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 42 43 DROP TABLE IF EXISTS `t_user_1`; 44 CREATE TABLE `t_user_1` ( 45 `id` int(11) NOT NULL, 46 `username` varchar(255) DEFAULT NULL, 47 `org_code` int(11) DEFAULT NULL, 48 PRIMARY KEY (`id`) 49 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 50 51 DROP TABLE IF EXISTS `t_user_2`; 52 CREATE TABLE `t_user_2` ( 53 `id` int(11) NOT NULL, 54 `username` varchar(255) DEFAULT NULL, 55 `org_code` int(11) DEFAULT NULL, 56 PRIMARY KEY (`id`) 57 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 58 59 #创建数据库db2 60 CREATE DATABASE IF NOT EXISTS `db2` DEFAULT CHARACTER SET utf8; 61 62 USE `db2`; 63 64 DROP TABLE IF EXISTS `t_user_0`; 65 CREATE TABLE `t_user_0` ( 66 `id` int(11) NOT NULL, 67 `username` varchar(255) DEFAULT NULL, 68 `org_code` int(11) DEFAULT NULL, 69 PRIMARY KEY (`id`) 70 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 71 72 DROP TABLE IF EXISTS `t_user_1`; 73 CREATE TABLE `t_user_1` ( 74 `id` int(11) NOT NULL, 75 `username` varchar(255) DEFAULT NULL, 76 `org_code` int(11) DEFAULT NULL, 77 PRIMARY KEY (`id`) 78 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4; 79 80 DROP TABLE IF EXISTS `t_user_2`; 81 CREATE TABLE `t_user_2` ( 82 `id` int(11) NOT NULL, 83 `username` varchar(255) DEFAULT NULL, 84 `org_code` int(11) DEFAULT NULL, 85 PRIMARY KEY (`id`) 86 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
3. 搭建工程
- 搭建Maven工程
- 修改pom.xml
1 <project xmlns="http://maven.apache.org/POM/4.0.0" 2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 <groupId>com.c3stones</groupId> 6 <artifactId>sharding-jdbc-demo</artifactId> 7 <version>0.0.1-SNAPSHOT</version> 8 <name>sharding-jdbc-demo</name> 9 <description>Sharding JDBC Demo</description> 10 11 <parent> 12 <groupId>org.springframework.boot</groupId> 13 <artifactId>spring-boot-starter-parent</artifactId> 14 <version>2.1.6.RELEASE</version> 15 <relativePath /> 16 </parent> 17 18 <properties> 19 <java.version>1.8</java.version> 20 <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version> 21 <mybatis-plus.version>3.3.1</mybatis-plus.version> 22 <sharding-jdbc.version>3.1.0</sharding-jdbc.version> 23 </properties> 24 25 <dependencies> 26 <dependency> 27 <groupId>mysql</groupId> 28 <artifactId>mysql-connector-java</artifactId> 29 <scope>runtime</scope> 30 </dependency> 31 <dependency> 32 <groupId>com.baomidou</groupId> 33 <artifactId>mybatis-plus-boot-starter</artifactId> 34 <version>${mybatis-plus.version}</version> 35 </dependency> 36 <dependency> 37 <groupId>io.shardingsphere</groupId> 38 <artifactId>sharding-jdbc-spring-boot-starter</artifactId> 39 <version>${sharding-jdbc.version}</version> 40 </dependency> 41 <dependency> 42 <groupId>io.shardingsphere</groupId> 43 <artifactId>sharding-jdbc-spring-namespace</artifactId> 44 <version>${sharding-jdbc.version}</version> 45 </dependency> 46 <dependency> 47 <groupId>org.projectlombok</groupId> 48 <artifactId>lombok</artifactId> 49 </dependency> 50 <dependency> 51 <groupId>org.springframework.boot</groupId> 52 <artifactId>spring-boot-starter-web</artifactId> 53 </dependency> 54 <dependency> 55 <groupId>org.springframework.boot</groupId> 56 <artifactId>spring-boot-starter-test</artifactId> 57 <scope>test</scope> 58 </dependency> 59 </dependencies> 60 61 <build> 62 <plugins> 63 <plugin> 64 <groupId>org.springframework.boot</groupId> 65 <artifactId>spring-boot-maven-plugin</artifactId> 66 </plugin> 67 </plugins> 68 </build> 69 </project>
- 编写实体类
1 import com.baomidou.mybatisplus.annotation.TableField; 2 import com.baomidou.mybatisplus.annotation.TableName; 3 import com.baomidou.mybatisplus.extension.activerecord.Model; 4 5 import lombok.Data; 6 import lombok.EqualsAndHashCode; 7 8 /** 9 * 用户信息 10 * 11 * @author CL 12 * 13 */ 14 @Data 15 @TableName(value = "t_user") 16 @EqualsAndHashCode(callSuper = false) 17 public class User extends Model<User> { 18 19 private static final long serialVersionUID = 1L; 20 private int id; 21 private String username; 22 @TableField(value = "org_code") 23 private int orgCode; 24 25 }
- 编写Mapper
1 import com.baomidou.mybatisplus.core.mapper.BaseMapper; 2 import com.c3stones.entity.User; 3 4 /** 5 * 用户Mapper 6 * 7 * @author CL 8 * 9 */ 10 public interface UserMapper extends BaseMapper<User> { 11 12 }
- 编写Service
1 import java.util.List; 2 3 import com.c3stones.entity.User; 4 5 /** 6 * 用户Service 7 * 8 * @author CL 9 * 10 */ 11 public interface UserService { 12 13 /** 14 * 查询用户列表 15 * 16 * @return 17 */ 18 List<User> findList(); 19 20 /** 21 * 保存用户信息 22 * 23 * @param user 24 * @return 25 */ 26 boolean save(User user); 27 28 }
1 import java.util.List; 2 3 import org.springframework.stereotype.Service; 4 5 import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl; 6 import com.c3stones.entity.User; 7 import com.c3stones.mapper.UserMapper; 8 import com.c3stones.service.UserService; 9 10 /** 11 * 用户Service实现类 12 * 13 * @author CL 14 * 15 */ 16 @Service 17 public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService { 18 19 /** 20 * 查询用户列表 21 * 22 * @return 23 */ 24 @Override 25 public List<User> findList() { 26 return new User().selectAll(); 27 } 28 29 /** 30 * 保存用户信息 31 * 32 * @param user 33 * @return 34 */ 35 @Override 36 public boolean save(User user) { 37 return super.save(user); 38 } 39 40 }
- 编写Controller
1 import java.util.List; 2 3 import org.springframework.beans.factory.annotation.Autowired; 4 import org.springframework.web.bind.annotation.GetMapping; 5 import org.springframework.web.bind.annotation.PostMapping; 6 import org.springframework.web.bind.annotation.RestController; 7 8 import com.c3stones.entity.User; 9 import com.c3stones.service.UserService; 10 11 /** 12 * 用户Controller 13 * 14 * @author CL 15 * 16 */ 17 @RestController 18 public class UserController { 19 20 @Autowired 21 private UserService userService; 22 23 @PostMapping(value = "save") 24 public boolean save(User user) { 25 return userService.save(user); 26 } 27 28 @GetMapping(value = "list") 29 public List<User> findList() { 30 return userService.findList(); 31 } 32 }
- 编写启动类
1 import org.mybatis.spring.annotation.MapperScan; 2 import org.springframework.boot.SpringApplication; 3 import org.springframework.boot.autoconfigure.SpringBootApplication; 4 5 /** 6 * 启动类 7 * 8 * @author CL 9 * 10 */ 11 @SpringBootApplication 12 @MapperScan(value = "com.c3stones.mapper") 13 public class Application { 14 15 public static void main(String[] args) { 16 SpringApplication.run(Application.class, args); 17 } 18 19 }
- 添加配置文件application.yml
1 spring: 2 main: 3 allow-bean-definition-overriding: true #允许Bean重复注入，后者覆盖前者 4 sharding: 5 jdbc: 6 datasource: 7 names: db0,db1,db2 8 db0: 9 type: com.zaxxer.hikari.HikariDataSource 10 driver-class-name: com.mysql.cj.jdbc.Driver 11 jdbc-url: jdbc:mysql://localhost:3306/db0?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC 12 username: root 13 password: root 14 db1: 15 type: com.zaxxer.hikari.HikariDataSource 16 driver-class-name: com.mysql.cj.jdbc.Driver 17 jdbc-url: jdbc:mysql://localhost:3306/db1?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC 18 username: root 19 password: root 20 db2: 21 type: com.zaxxer.hikari.HikariDataSource 22 driver-class-name: com.mysql.cj.jdbc.Driver 23 jdbc-url: jdbc:mysql://localhost:3306/db2?useUnicode=true&useJDBCCompliantTimezoneShift=true&useLegacyDatetimeCode=false&serverTimezone=UTC 24 username: root 25 password: root 26 config: 27 props: 28 sql.show: true #打印sql 29 sharding: 30 default-database-strategy: #默认分库策略 31 inline: 32 sharding-column: id 33 algorithm-expression: db$->{id % 3} 34 tables: 35 t_user: 36 actual-data-nodes: db$->{0..2}.t_user_$->{0..2} #实际节点 37 table-strategy: #分表策略 38 inline: 39 sharding-column: org_code 40 algorithm-expression: t_user_$->{org_code % 3}
4. 测试
测试时观察控制台打印的SQL。
- 保存用户信息，id=1
控制台：
2020-04-29 12:41:36.849 INFO 4384 --- [nio-8080-exec-6] ShardingSphere-SQL : Rule Type: sharding 2020-04-29 12:41:36.850 INFO 4384 --- [nio-8080-exec-6] ShardingSphere-SQL : Logic SQL: INSERT INTO t_user ( id, username, org_code ) VALUES ( ?, ?, ? ) 2020-04-29 12:41:36.850 INFO 4384 --- [nio-8080-exec-6] ShardingSphere-SQL : SQLStatement: InsertStatement(super=DMLStatement(super=io.shardingsphere.core.parsing.parser.sql.dml.insert.InsertStatement@37b6baa2), columns=[Column(name=id, tableName=t_user), Column(name=username, tableName=t_user), Column(name=org_code, tableName=t_user)], generatedKeyConditions=[], insertValues=InsertValues(insertValues=[InsertValue(type=VALUES, expression=( ?, ?, ? ), parametersCount=3)]), columnsListLastPosition=45, generateKeyColumnIndex=-1, insertValuesListLastPosition=67) 2020-04-29 12:41:36.850 INFO 4384 --- [nio-8080-exec-6] ShardingSphere-SQL : Actual SQL: db1 ::: INSERT INTO t_user_2 ( id, username, org_code ) VALUES ( ?, ?, ? ) ::: [[1, 张三, 1001]]
- 保存用户信息，id=2
控制台：
1 2020-04-29 12:40:34.611 INFO 4384 --- [nio-8080-exec-3] ShardingSphere-SQL : Rule Type: sharding 2 2020-04-29 12:40:34.611 INFO 4384 --- [nio-8080-exec-3] ShardingSphere-SQL : Logic SQL: INSERT INTO t_user ( id, 3 username, 4 org_code ) VALUES ( ?, 5 ?, 6 ? ) 7 2020-04-29 12:40:34.611 INFO 4384 --- [nio-8080-exec-3] ShardingSphere-SQL : SQLStatement: InsertStatement(super=DMLStatement(super=io.shardingsphere.core.parsing.parser.sql.dml.insert.InsertStatement@37b6baa2), columns=[Column(name=id, tableName=t_user), Column(name=username, tableName=t_user), Column(name=org_code, tableName=t_user)], generatedKeyConditions=[], insertValues=InsertValues(insertValues=[InsertValue(type=VALUES, expression=( ?, 8 ?, 9 ? ), parametersCount=3)]), columnsListLastPosition=45, generateKeyColumnIndex=-1, insertValuesListLastPosition=67) 10 2020-04-29 12:40:34.611 INFO 4384 --- [nio-8080-exec-3] ShardingSphere-SQL : Actual SQL: db2 ::: INSERT INTO t_user_0 ( id, 11 username, 12 org_code ) VALUES ( ?, 13 ?, 14 ? ) ::: [[2, 李四, 1002]]
- 保存用户信息，id=3
控制台：
1 2020-04-29 12:42:02.260 INFO 4384 --- [nio-8080-exec-1] ShardingSphere-SQL : Rule Type: sharding 2 2020-04-29 12:42:02.263 INFO 4384 --- [nio-8080-exec-1] ShardingSphere-SQL : Logic SQL: INSERT INTO t_user ( id, 3 username, 4 org_code ) VALUES ( ?, 5 ?, 6 ? ) 7 2020-04-29 12:42:02.263 INFO 4384 --- [nio-8080-exec-1] ShardingSphere-SQL : SQLStatement: InsertStatement(super=DMLStatement(super=io.shardingsphere.core.parsing.parser.sql.dml.insert.InsertStatement@37b6baa2), columns=[Column(name=id, tableName=t_user), Column(name=username, tableName=t_user), Column(name=org_code, tableName=t_user)], generatedKeyConditions=[], insertValues=InsertValues(insertValues=[InsertValue(type=VALUES, expression=( ?, 8 ?, 9 ? ), parametersCount=3)]), columnsListLastPosition=45, generateKeyColumnIndex=-1, insertValuesListLastPosition=67) 10 2020-04-29 12:42:02.263 INFO 4384 --- [nio-8080-exec-1] ShardingSphere-SQL : Actual SQL: db0 ::: INSERT INTO t_user_1 ( id, 11 username, 12 org_code ) VALUES ( ?, 13 ?, 14 ? ) ::: [[3, 赵六, 1003]]
- 查询用户信息
控制台：
1 2020-04-29 12:42:15.962 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Rule Type: sharding 2 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Logic SQL: SELECT id,username,org_code FROM t_user 3 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : SQLStatement: SelectStatement(super=DQLStatement(super=io.shardingsphere.core.parsing.parser.sql.dql.select.SelectStatement@53468979), containStar=false, firstSelectItemStartPosition=8, selectListLastPosition=29, groupByLastPosition=0, items=[CommonSelectItem(expression=id, alias=Optional.absent()), CommonSelectItem(expression=username, alias=Optional.absent()), CommonSelectItem(expression=org_code, alias=Optional.absent())], groupByItems=[], orderByItems=[], limit=null, subQueryStatement=null, subQueryStatements=[], subQueryConditions=[]) 4 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db0 ::: SELECT id,username,org_code FROM t_user_0 5 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db0 ::: SELECT id,username,org_code FROM t_user_1 6 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db0 ::: SELECT id,username,org_code FROM t_user_2 7 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db1 ::: SELECT id,username,org_code FROM t_user_0 8 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db1 ::: SELECT id,username,org_code FROM t_user_1 9 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db1 ::: SELECT id,username,org_code FROM t_user_2 10 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db2 ::: SELECT id,username,org_code FROM t_user_0 11 2020-04-29 12:42:15.963 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db2 ::: SELECT id,username,org_code FROM t_user_1 12 2020-04-29 12:42:15.964 INFO 4384 --- [nio-8080-exec-4] ShardingSphere-SQL : Actual SQL: db2 ::: SELECT id,username,org_code FROM t_user_2