SpringBoot分组查询

引入MybatisPlusConfig 插件

新建一个名字为config的文件夹，在该文件夹下新建MybatisPlusConfig.java类

1.作用

@Configuration注解的作用：声明一个类为配置类，用于取代bean.xml配置文件注册bean对象。

2.基础运用

@Configuration注解最常见的搭配使用有两个：@Bean和@Scope

@Bean标注在方法上给容器注册组件，默认是单实例的

导入插件代码：

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@Configuration
public class MybatisPlusConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.H2));
        return interceptor;
    }
}

编写service文件夹下的接口

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public IPage<Student> getPage(int currentPage, int pageSize, Student student);

编写Impl

注释部分为分组条件查询

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@Override
public IPage<Student> getPage(int currentPage, int pageSize, Student student) {
    IPage<Student> page = new Page<>(currentPage, pageSize);
    /*LambdaQueryWrapper<Student> lqw = new LambdaQueryWrapper();
    lqw.like(Strings.isNotEmpty(student.getUsername()), Student::getUsername, student.getUsername());
    lqw.like(Strings.isNotEmpty(student.getPassword()), Student::getPassword, student.getPassword());
                             lqw.like(Strings.isNotEmpty(student.getEmail()),Student::getEmail,student.getEmail());	
   */
   
    studentMapper2.selectPage(page, lqw);
    return page;
}

Controller类

编写个人创建的Controller类

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@GetMapping("/{currentPage}/{pageSize}")
public IPage<Student> getPage(@PathVariable int currentPage,@PathVariable int pageSize, Student student){

    return studentService.getPage(currentPage, pageSize, student);
}