public string mapping_sotaikhoan_by_id(decimal ip_dc_id_gv) { if (ip_dc_id_gv == 0) { return(""); } US_V_DM_GIANG_VIEN v_dm_gv = new US_V_DM_GIANG_VIEN(ip_dc_id_gv); if (v_dm_gv.IsSO_TAI_KHOANNull()) { return(""); } return(v_dm_gv.strSO_TAI_KHOAN); }