/// <summary>
 /// 查找符合条件记录的总条数
 /// </summary>
 /// <param name="conditions">查询条件</param>
 /// <returns>返回符合的记录条数</returns>
 public string GetCount_infos(string conditions)
 {
     return(DbHelperSQL.GetCountByConditions(new infos(), conditions));
 }