文章目錄
1 Sharding-JDBC簡介
是輕量級的java框架，是增強版的JDBC驅動，
2 Sharding-JDBC
Sharding-JDBC 不是做分庫分表
主要目的是簡化對分庫分表之後相關數據操作
主要做兩個功能 數據分片和讀寫分離
3 Sharding-JDBC實現水平分表
3.1 搭建環境
3.1.1 總體概覽
SpringBoot + MybaitsPlus + Sharding-JDBC + Druid 連接池
3.1.2 創建SpringBoot工程
pom.xml 如下：
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.3.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.ccb</groupId>
<artifactId>shardingsphere</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>shardingsphere</name>
<description>Sharding sphere project for Spring Boot</description>
<properties>
<java.version>1.8.251</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.20</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.15</version>
</dependency>
<dependency>
<groupId>org.apache.shardingsphere</groupId>
<artifactId>sharding-jdbc-spring-boot-starter</artifactId>
<version>4.0.0-RC1</version>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.0.5</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
3.1.3 按照水平分表的方式，創建數據庫和數據庫表
創建數據庫 coursedb
CREATE SCHEMA `coursedb` DEFAULT CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci ;
創建數據庫表 course1 course2
CREATE TABLE `coursedb`.`course1` (
`cid` BIGINT NOT NULL,
`cname` VARCHAR(45) NOT NULL,
`user_id` BIGINT NOT NULL,
`cstatus` VARCHAR(45) NOT NULL,
PRIMARY KEY (`cid`));
CREATE TABLE `coursedb`.`course2` (
`cid` BIGINT NOT NULL,
`cname` VARCHAR(45) NOT NULL,
`user_id` BIGINT NOT NULL,
`cstatus` VARCHAR(45) NOT NULL,
PRIMARY KEY (`cid`));
約定規則 如果添加課程id爲奇數把數據添加course2，如果添加課程id爲偶數把數據添加到course1
3.2 代碼實現
3.2.1 創建po實體類
package com.ccb.sharding.po;
public class Course {
private Long cid;
private String cname;
private Long userId;
private String cstatus;
public Long getCid() {
return cid;
}
public void setCid(Long cid) {
this.cid = cid;
}
public String getCname() {
return cname;
}
public void setCname(String cname) {
this.cname = cname;
}
public Long getUserId() {
return userId;
}
public void setUserId(Long userId) {
this.userId = userId;
}
public String getCstatus() {
return cstatus;
}
public void setCstatus(String cstatus) {
this.cstatus = cstatus;
}
@Override
public String toString() {
return "Course{" +
"cid=" + cid +
", cname='" + cname + '\'' +
", userId=" + userId +
", cstatus='" + cstatus + '\'' +
'}';
}
}
3.2.2 創建mapper 接口
package com.ccb.sharding.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.ccb.sharding.po.Course;
import org.springframework.stereotype.Repository;
@Repository
public interface CourseMapper extends BaseMapper<Course> {
}
3.2.3 添加到MapperScan掃描
package com.ccb.sharding;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.ccb.sharding.mapper")
public class ShardingApplication {
public static void main(String[] args) {
SpringApplication.run(ShardingApplication.class, args);
}
}
3.3 配置分片策略
在application.properties文件中增加如下配置
# sharding-JDBC分片策略
# 配置數據源，給數據源命名
spring.shardingsphere.datasource.names=ds1
# 配置數據源具體內容，連接池、驅動、地址、用戶名和密碼
spring.shardingsphere.datasource.ds1.type=com.alibaba.druid.pool.DruidDataSource
spring.shardingsphere.datasource.ds1.driver-class-name=com.mysql.cj.jdbc.Driver
spring.shardingsphere.datasource.ds1.url=jdbc:mysql://localhost:3306/coursedb?serverTimezone=GMT%2B8
spring.shardingsphere.datasource.ds1.username=root
spring.shardingsphere.datasource.ds1.password=chengwen
# 一個實體類對應兩張表，覆蓋
spring.main.allow-bean-definition-overriding=true
# 指定數據表course分佈情況，配置表在哪個數據庫裏面，表名稱都是什麼
spring.shardingsphere.sharding.tables.course.actual-data-nodes=ds1.course$->{1..2}
# 指定course 表裏面主鍵cid 生成策略 SNOWFLAKE 雪花算法
spring.shardingsphere.sharding.tables.course.key-generator.column=cid
spring.shardingsphere.sharding.tables.course.key-generator.type=SNOWFLAKE
#指定分片策略 約定cid的值偶數添加到course1表，奇數添加到course2表
spring.shardingsphere.sharding.tables.course.table-strategy.inline.sharding-column=cid
spring.shardingsphere.sharding.tables.course.table-strategy.inline.algorithm-expression=course$->{cid % 2 + 1}
# 打印sql輸出日誌
spring.shardingsphere.properties.sql.show=true
3.4 Test
package com.ccb.sharding;
import com.ccb.sharding.mapper.CourseMapper;
import com.ccb.sharding.po.Course;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest
class ShardingApplicationTests {
@Autowired
CourseMapper courseMapper;
@Test
public void addCourse() {
for (int i = 1 ; i <= 10 ; i ++){
Course course = new Course();
course.setCname("Java" + i);
course.setCstatus("Normal" + i);
course.setUserId(100L);
courseMapper.insert(course);
}
}
@Test
public void getCourse(){
QueryWrapper queryWrapper = new QueryWrapper();
queryWrapper.eq("cid",481545888309706752L);
Course course = courseMapper.selectOne(queryWrapper);
System.out.println(course);
}
}
3.5 Test result
分表1
分表2
getCourse
