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SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

一、前言

小編最近一直在研究關于分庫分表的東西,前幾天docker安裝了mycat實作了分庫分表,但是都在說mycat的bug很多。很多人還是傾向于shardingsphere,其實他是一個全家桶,有JDBC、Proxy 和 Sidecar組成,小編今天以最簡單的JDBC來簡單整合一下!

現在最新版已經是5.1.1,經過一天的研究用于解決了所有問題,完成了單庫分表!!

二、踩過的坑

1. 資料源問題

不要使用druid-spring-boot-starter這個依賴,啟動會有問題

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.21</version>
</dependency>           

報錯資訊:

Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'userMapper' defined in file 
[D:\jiawayun\demo\target\classes\com\example\demo\mapper\UserMapper.class]:
 Invocation of init method failed; nested exception is 
 java.lang.IllegalArgumentException: Property 'sqlSessionFactory' 
 or 'sqlSessionTemplate' are required           

==解決方案:==

使用單獨的druid

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.2.8</version>
</dependency>           

建議使用==預設的資料源==,sharding-jdbc也是使用的預設的資料源,小編使用的自帶的,忘記druid後面會不會有問題了!!

type: com.zaxxer.hikari.HikariDataSource           

2. Insert 語句不支援分表路由到多個資料節點

報錯資訊:

Insert statement does not support sharding table routing to multiple data nodes.

解決方案:

解決不支援分表路由問題:https://blog.csdn.net/qq_52423918/article/details/125004312

三、導入maven依賴

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
    <exclusions>
        <exclusion>
            <groupId>org.junit.vintage</groupId>
            <artifactId>junit-vintage-engine</artifactId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.apache.shardingsphere</groupId>
    <artifactId>shardingsphere-jdbc-core-spring-boot-starter</artifactId>
    <version>5.1.1</version>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-test</artifactId>
    <scope>test</scope>
</dependency>
<!-- lombok -->
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.18.10</version>
</dependency>
<!--jdbc-->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<!-- mysql -->
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>

<!-- mybatis-plus -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.5.1</version>
</dependency>           

四、建立表

1. 建立二張表

命名為:user_0、user_1

CREATE TABLE `user_0`  (
  `cid` bigint(25) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `gender` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `data` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`cid`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

SET FOREIGN_KEY_CHECKS = 1;           

2. 資料庫結構

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

五、架構全局展示

1. User實體類

@Data
public class User implements Serializable {
    private static final long serialVersionUID = 337361630075002456L;

    private Long cid;

    private String name;

    private String gender;

    private String data;

}           

2. controller

@RestController
@RequestMapping("/test")
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/insertTest")
    public void insertTest(){
        for (int i = 1 ; i < 10; i++) {
            User test = new User("王"+i,"男","資料" + i);
            userMapper.insert(test);
        }
    }
}           

3. mapper

我們直接省略了service,簡單一下哈!!

public interface UserMapper extends BaseMapper<User> {
}           

4. application.yml配置

server:
  port: 8089

spring:
  shardingsphere:
    mode:
      type: memory
    # 是否開啟
    datasource:
      # 資料源(邏輯名字)
      names: m1
      # 配置資料源
      m1:
        type: com.zaxxer.hikari.HikariDataSource
        driver-class-name: com.mysql.cj.jdbc.Driver
        url: jdbc:mysql://localhost:3306/test?useSSL=false&autoReconnect=true&characterEncoding=UTF-8&serverTimezone=UTC
        username: root
        password: root
    # 分片的配置
    rules:
      sharding:
        # 表的分片政策
        tables:
          # 邏輯表的名稱
          user:
            # 資料節點配置,采用Groovy表達式
            actual-data-nodes: m1.user_$->{0..1}
            # 配置政策
            table-strategy:
              # 用于單分片鍵的标準分片場景
              standard:
                sharding-column: cid
                # 分片算法名字
                sharding-algorithm-name: user_inline
            key-generate-strategy: # 主鍵生成政策
              column: cid  # 主鍵列
              key-generator-name: snowflake  # 政策算法名稱(推薦使用雪花算法)
        key-generators:
          snowflake:
            type: SNOWFLAKE
        sharding-algorithms:
          user_inline:
            type: inline
            props:
              algorithm-expression: user_$->{cid % 2}
    props:
      # 日志顯示具體的SQL
      sql-show: true


logging:
  level:
    com.wang.test.demo: DEBUG

mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.example.demo.entity
  configuration:
    #在映射實體或者屬性時,将資料庫中表名和字段名中的下劃線去掉,按照駝峰命名法映射 address_book ---> addressBook
    map-underscore-to-camel-case: true           

5. 啟動類

@MapperScan("com.example.demo.mapper")
@SpringBootApplication
public class DemoApplication {

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }

}           

六、測試插入九條資料

==本次測試政策是:行表達式分片政策:inline==

1. 插入資料

輸入 :localhost:8089/test/insertTest

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

==分片成功==

2. 單個查詢

@GetMapping("/selectOneTest")
public void selectOneTest(){

    User user = userMapper.selectOne(Wrappers.<User>lambdaQuery().eq(User::getCid,736989417020850176L));
    System.out.println(user);

}           

這時他會根據cid去自動擷取去那個表中擷取資料

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

3. 全查詢

@GetMapping("/selectListTest")
public void selectListTest(){

    List<User> list = userMapper.selectList(null);
    System.out.println(list);

}           

由于沒有條件,他會去把兩個表UNION ALL進行彙總

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

4. 分頁查詢

需要先配置mybatis-plus分頁配置類:

@Configuration
public class MybatisPlusConfig {

    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}
@GetMapping("/selectListPage")
public void selectListPage(){
    IPage<User> page = new Page(1,6);
    IPage<User> userIPage = userMapper.selectPage(page,null);
    List<User> records = userIPage.getRecords();
    System.out.println(records);
}           

我們user_0有5條資料,user_1有4條資料

==我們發現它會向所有的表中去進行一遍分頁查詢,第一個表資料不夠就會加上另一個表分頁拿到的值==

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

==分頁size為3時,一個user_0就可以滿足分頁條件,就會忽略user_1的分頁資料。==

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

5. 非分片屬性查詢

我們先把user_0表性别修改兩個為女,然後進行查詢!看看沒有分片的字段是否能夠隻去user_0去查詢

@GetMapping("/selectListByGender")
public void selectListByGender(){

    List<User> list = userMapper.selectList(Wrappers.<User>lambdaQuery().eq(User::getGender, "女"));
    System.out.println(list);
}           

有圖可見:不是分片的字段查詢,回去全連接配接表去查詢一遍,效率和不分表一樣了哈!!

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

6. 分片屬性來自一個表in查詢

@GetMapping("/selectInList")
public void selectList(){
    List<User> users = userMapper.selectList(Wrappers.<User>lambdaQuery().in(User::getCid,736989417020850176L,736989418119757824L));
    System.out.println(users);
}           

我們可以發現,我們根據分片字段進行in查詢,sharding-jdbc會識别出來來自于那個表進而提高效率,不會所有的表進行全連接配接。

SpringBoot+Mybatis-Plus整合Sharding-JDBC5.1.1實作單庫分表

七、總結

這樣就完成了最新版的sharding-jdbc的簡單測試和一些坑的解決,總的來說配置很費勁,不能有一定的錯誤!