MyBatis-Plus实现条件查询的三种格式例举详解

		QueryWrapper qw = new QueryWrapper();
		//lt是小于，id小于5
		qw.lt("id",5);
		List<User> users = userDao.selectList(qw);
		System.out.println(users);

		QueryWrapper qw = new QueryWrapper();
		//大于2小于5
		qw.lt("id",5).gt("id",2);
		List<User> users = userDao.selectList(qw);
		System.out.println(users);

		QueryWrapper<User> qw = new QueryWrapper<User>();
		//lt是小于，id小于5
		qw.lambda().lt(User::getId,5);
		List<User> users = userDao.selectList(qw);
		System.out.println(users);

		LambdaQueryWrapper<User> lqw = new LambdaQueryWrapper<>();
		//2-5，即3,4
		lqw.lt(User::getId,5).gt(User::getId,2);
		//上面是并且，下面是或
		//lqw.lt(User::getId,2).or().gt(User::getId,5);
		List<User> users = userDao.selectList(lqw);
		System.out.println(users);

  //模拟获取前端的数据
		//UserQuery是User的继承类,这样既可以模仿id的上下限
        UserQuery uq = new UserQuery();
        uq.setId(7);
        uq.setId2(3);
        LambdaQueryWrapper<User> lqw = new LambdaQueryWrapper<>();
        lqw.lt(null!=uq.getId(),User::getId, uq.getId())
				.gt(null!=uq.getId2(),User::getId, uq.getId2());
        List<User> users = userDao.selectList(lqw);
        System.out.println(users);