MyBatis-Plus快速入门（四）性能分析插件、条件构造器

/**
* SQL执行效率插件
*/
@Bean
@Profile({"dev","test"})//设置dev test环境开启，保证我们的效率
public PerformanceInterceptor performanceInterceptor(){
    PerformanceInterceptor performanceInterceptor = new PerformanceInterceptor();
    performanceInterceptor.setMaxTime(1);//ms毫秒 设置sql执行的最大时间，如果超过了则不执行
    performanceInterceptor.setFormat(true);//是否开启格式化（开启）
    return performanceInterceptor;
}

#开发环境
spring.profiles.active=dev

    //测试通过id查询用户
    @Test
    public void selectById(){
        SysUser sysUser = userMapper.selectById(1303211966619484161L);
        System.out.println(sysUser);
    }

@SpringBootTest
public class WrapperApplication {

    @Autowired
    private UserMapper userMapper;

    //查询name不为空的用户，并且邮箱不为空且年龄大于等于12的用户
    @Test
    public void contextLoads(){
        QueryWrapper<SysUser> wrapper=new QueryWrapper<SysUser>();
        wrapper.isNotNull("username")
                .isNotNull("email")
                .ge("age", 18);
        List<SysUser> users = userMapper.selectList(wrapper);
        users.forEach(System.out::println);
    }

    //查询名字叫XXX的一个人
    @Test
    public void contextLoads2(){
        QueryWrapper<SysUser> wrapper = new QueryWrapper<>();
        wrapper.eq("username", "手残");
        SysUser sysUser = userMapper.selectOne(wrapper);
        System.out.println("username = " + sysUser);
    }

    //查询年龄在21到30之间的用户
    @Test
    public void contextLoads3_1(){
        QueryWrapper<SysUser> wrapper = new QueryWrapper<>();
        wrapper.between("age", 21, 30);
        List<SysUser> user = userMapper.selectList(wrapper);//查询一个数据有结果数据时我们可以使用List 或者 Map
        user.forEach(System.out::println);
    }

    //查询年龄在21到30之间的用户数
    @Test
    public void contextLoads3_2(){
        QueryWrapper<SysUser> wrapper = new QueryWrapper<>();
        wrapper.between("age", 21, 30);//区间
        Integer count = userMapper.selectCount(wrapper);//查询结果数
        System.out.println("count = " + count);
    }

    //查询名字不含j的而且email以t开头的
    @Test
    public void contextLoads4(){
        QueryWrapper<SysUser> wrapper = new QueryWrapper<>();
        wrapper.notLike("username", "j")
                .likeRight("email", "t");
        List<Map<String, Object>> maps = userMapper.selectMaps(wrapper);
        maps.forEach(System.out::println);
    }

    //id在子查询查出来
    @Test
    public void contextLoads5(){
        QueryWrapper<SysUser> wrapper = new QueryWrapper<>();
        wrapper.inSql("user_id", "select user_id from sys_user where user_id < 3");
        List<Object> objects = userMapper.selectObjs(wrapper);
        objects.forEach(System.out::println);
    }


    //查询name不为空的用户、并且邮箱不为空、且年龄大于等于16的用户,并按age升序排序
    @Test
    public void contextLoads6(){
        QueryWrapper<SysUser> wrapper=new QueryWrapper<SysUser>();
        wrapper.isNotNull("username")
                .isNotNull("email")
                .ge("age", 12)
                .orderByAsc("age");
        List<SysUser> users = userMapper.selectList(wrapper);
        users.forEach(System.out::println);
    }
}