这要考虑super特殊情况
https://github.com/TaleLin/lin-cms-koa/blob/ae56b21eb1400c8e900e043d4f54905ea3d7760d/app/dao/admin.js#L18

已用sequelize，应多用orm，少用sql原生语句，提高可读性。
```
async getUsers (ctx, groupId, start, count1) {
    const { lin_user } = db.models;
    const where = {
      nickname: {
        $ne: "super"
      }
    };
    groupId && (where.group_id = groupId);
    const users = await lin_user.findAll({ where });  // 分页暂不考虑
    const { count } = await lin_user.findAndCount({ where });
    users.map(user => {
      unsets(user, ["update_time", "delete_time", "password"]);
      user.create_time = dayjs(user.create_time).unix();
      return user;
    });
    return {
      users,
      total: count
    };
  }
```