环境

<dependency><groupId>com.baomidou</groupId><artifactId>dynamic-datasource-spring-boot-starter</artifactId><version>3.4.1</version>
</dependency>

<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus</artifactId><version>3.1.2</version>
</dependency>

配置信息

其中库为  postgresql  和 mysql ,默认postgresql为主库

配置信息如下

mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
spring.datasource.dynamic.primary=postgresql
spring.datasource.dynamic.strict=true

spring.datasource.dynamic.datasource.mysql.url=jdbc:mysql://localhost:3306/spring_boot_test?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&useSSL=false
spring.datasource.dynamic.datasource.mysql.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.dynamic.datasource.mysql.username=root
spring.datasource.dynamic.datasource.mysql.password=123456spring.datasource.dynamic.datasource.postgresql.url=jdbc:postgresql://localhost:7092/postgres
spring.datasource.dynamic.datasource.postgresql.driver-class-name=org.postgresql.Driver
spring.datasource.dynamic.datasource.postgresql.username=postgres
spring.datasource.dynamic.datasource.postgresql.password=123456

mapper文件 

利用DS来指定需要操作的数据库

@DS("mysql")
@Mapper
public interface CtmThirdAskForLeaveMapper extends BaseMapper<CtmThirdAskForLeave> {}

@DS("postgresql")
@Mapper
public interface CtmAskForLeaveMapper extends BaseMapper<CtmAskForLeave> {}

重写SqlSessionFactory

这步非常关键，如果不重写，可能导致分页不会返回total,以及无法使用原生BaseMapper

导致报错 Invalid bound statement (not found)

@Configuration
@MapperScan("mappper所在包")
public class MybatisPlusConfig {/*** 分页插件*/@Beanpublic PaginationInterceptor paginationInterceptor(){return new PaginationInterceptor();}@Beanpublic SqlSessionFactory sqlSessionFactory(DataSource dataSource) throws Exception {MybatisSqlSessionFactoryBean sqlSessionFactoryBean = new MybatisSqlSessionFactoryBean();sqlSessionFactoryBean.setDataSource(dataSource);sqlSessionFactoryBean.setMapperLocations(new PathMatchingResourcePatternResolver().getResources("classpath*:mapper/*/*.xml"));sqlSessionFactoryBean.setTransactionFactory(new SpringManagedTransactionFactory());sqlSessionFactoryBean.setPlugins(new Interceptor[]{paginationInterceptor()});return sqlSessionFactoryBean.getObject();}}

测试代码

public interface CtmAskForLeaveService extends IService<CtmAskForLeave> {/*** 处理数据* @return*/Boolean messageAskForLeave();}

@Service
@Slf4j
public class CtmAskForLeaveServiceImpl extends ServiceImpl<CtmAskForLeaveMapper, CtmAskForLeave> implements CtmAskForLeaveService {@Overridepublic Boolean messageAskForLeave() {List<CtmThirdAskForLeave> ctmThirdAskForLeaves = ctmThirdAskForLeaveMapper.selectList(null);}
}