查询当前用户是否关注被浏览用户

查询粉丝表 若粉丝id和用户id匹配则表示关注 反之未关注

    @Override
    public GraceJSONResult isMeFollowThisWriter(String writerId, String fanId) {
        // 0. 判断传入参数是否合法
        if (StringUtils.isBlank(writerId) || StringUtils.isBlank(fanId)) {
            GraceException.display(ResponseStatusEnum.USERNAME_NOTFOUND);
        }

        // 1. 根据userId和fanId统计条数 若大于0 则表示已关注
        Boolean result = fanService.queryFanCountByUserId(writerId, fanId);

        return GraceJSONResult.ok(result);
    }

    @Override
    public boolean queryFanCountByUserId(String writerId, String fanId) {
        QueryWrapper<Fans> queryWrapper = new QueryWrapper<>();

        queryWrapper.eq("fan_id", fanId);
        queryWrapper.eq("writer_id", writerId);

        Integer result = fanMapper.selectCount(queryWrapper);


        return result > 0;
    }