SpringBoot与MybatisPlus3.X整合之动态表名 SQL 解析器(七)

• pom.xml

  <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter</artifactId>
          </dependency>
          <dependency>
              <groupId>com.baomidou</groupId>
              <artifactId>mybatis-plus-boot-starter</artifactId>
              <version>3.2.0</version>
          </dependency>
          <dependency>
              <groupId>org.projectlombok</groupId>
              <artifactId>lombok</artifactId>
          </dependency>
          <!-- https://mvnrepository.com/artifact/p6spy/p6spy -->
          <dependency>
              <groupId>p6spy</groupId>
              <artifactId>p6spy</artifactId>
              <version>3.8.0</version>
          </dependency>
          <dependency>
              <groupId>com.h2database</groupId>
              <artifactId>h2</artifactId>
              <scope>runtime</scope>
          </dependency>
  ​
          <dependency>
              <groupId>com.alibaba</groupId>
              <artifactId>fastjson</artifactId>
              <version>1.2.49</version>
              <scope>test</scope>
          </dependency>
          <!-- for testing -->
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-test</artifactId>
              <scope>test</scope>
          </dependency>
      </dependencies>

• application.yml

  spring:
    datasource:
      driver-class-name: com.p6spy.engine.spy.P6SpyDriver
      url: jdbc:p6spy:h2:tcp://192.168.180.115:19200/~/mem/test
      username: root
      password: test
  ​
  # Logger Config
  logging:
    level:
      com.mp.dynamic-tablename: debug

• 配置类

  实现 ITableNameHandler 接口注入到 DynamicTableNameParser 处理器链中，将动态表名解析器注入到 MP 解析链。

  @Configuration
  @MapperScan("com.mq.dynamictablename.mapper")
  public class MybatisPlusConfig {
  ​
      @Bean
      public PaginationInterceptor paginationInterceptor() {
          PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
          DynamicTableNameParser dynamicTableNameParser = new DynamicTableNameParser();
          dynamicTableNameParser.setTableNameHandlerMap(new HashMap<String, ITableNameHandler>(2) {{
              put("user", (metaObject, sql, tableName) -> {
                  // metaObject 可以获取传入参数，这里实现你自己的动态规则
                  String year = "_2018";
                  int random = new Random().nextInt(10);
                  if (random % 2 == 1) {
                      year = "_2019";
                  }
                  return tableName + year;
              });
          }});
          paginationInterceptor.setSqlParserList(Collections.singletonList(dynamicTableNameParser));
          return paginationInterceptor;
      }
  }

  ​

• 实体类

  @Data
  @Accessors(chain = true)
  public class User {
      private Long id;
      private String name;
      private Integer age;
      private String email;
  ​
  }
  public interface UserMapper extends BaseMapper<User> {
  ​
  }

• 数据库脚本

  DELETE FROM user_2018;
  ​
  INSERT INTO user_2018 (id, name, age, email) VALUES
  (1, 'Jone', 18, 'test1@baomidou.com');
  ​
  DELETE FROM user_2019;
  ​
  INSERT INTO user_2019 (id, name, age, email) VALUES
  (1, 'Jack', 20, 'test2@baomidou.com');
  DROP TABLE IF EXISTS user_2018;
  ​
  CREATE TABLE user_2018
  (
      id BIGINT(20) NOT NULL COMMENT '主键ID',
      name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
      age INT(11) NULL DEFAULT NULL COMMENT '年龄',
      email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
      PRIMARY KEY (id)
  );
  ​
  DROP TABLE IF EXISTS user_2019;
  ​
  CREATE TABLE user_2019
  (
      id BIGINT(20) NOT NULL COMMENT '主键ID',
      name VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
      age INT(11) NULL DEFAULT NULL COMMENT '年龄',
      email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
      PRIMARY KEY (id)
  );

• 测试类

  @SpringBootTest
  class DynamicTablenameApplicationTests {
  ​
  ​
      @Autowired
      private UserMapper userMapper;
  ​
      @Test
      public void test() {
          // 自己去观察打印 SQL 目前随机访问 user_2018  user_2019 表
          for (int i = 0; i < 6; i++) {
              User user = userMapper.selectById(1);
              System.err.println(user.getName());
          }
      }
  ​
  }

• 测试结果：

Consume Time：19 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2018 WHERE id=1
​
Jone
 Consume Time：2 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2019 WHERE id=1
​
Jack
 Consume Time：0 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2019 WHERE id=1
​
Jack
 Consume Time：0 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2019 WHERE id=1
​
Jack
 Consume Time：0 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2018 WHERE id=1
​
Jone
 Consume Time：0 ms 2019-10-30 16:46:39
 Execute SQL：SELECT id,name,email,age FROM user_2018 WHERE id=1
​
Jone