C# 在命令执行期间，当我检索时遇到致命错误

我正在尝试检索大量数据，查询如下：

SELECT GROUP_CONCAT(DISTINCT(ps1.`FullName`)) SELL,
       GROUP_CONCAT(DISTINCT(ps2.`FullName`)) BUY,
       h.RefNo REFERENCESNo,
       pd.ProID PersonalID,
       h.Taariikh DateRef
FROM heshiis h,
     persondetails pd,

  (SELECT DISTINCT pss.`FullName`,
                   pds1.ProID
   FROM person pss
   INNER JOIN persondetails pds1 ON pds1.PID=pss.PID
   WHERE pds1.DetailStatus LIKE '%ISKAGADE'
   ORDER BY pss.FullName DESC)ps1,

  (SELECT DISTINCT pss2.`FullName`,
                   pds2.ProID
   FROM person pss2
   INNER JOIN persondetails pds2 ON pds2.PID=pss2.PID
   WHERE pds2.DetailStatus LIKE '%IIBSADE'
   ORDER BY pss2.FullName DESC)ps2