group by后面多个字段，只想按照第一个字段

select M.cCusName ,M.cSOCode ,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney from SO_SOMain M,SO_SODetails D where D.cSOCode = M.cSOCode GROUP BY M.cSOCode ,M.cCusName,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney

group by后面多个字段，只想按照第一个字段M.cCusName排序，百度无果，求助大神！
[解决办法]
select?M.cCusName?,M.cSOCode?,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney?from?SO_SOMain?M,SO_SODetails?D?where?D.cSOCode?=?M.cSOCode?
GROUP?BY?M.cSOCode?,M.cCusName,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney
order by m.csocode

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[解决办法]
加一个order by M.cCusName

select M.cCusName ,M.cSOCode ,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney 
from SO_SOMain M,SO_SODetails D 
where D.cSOCode = M.cSOCode 
GROUP BY M.cSOCode ,M.cCusName,M.dDate,D.cInvName,D.cInvCode,D.iQuantity,D.iUnitPrice,D.iNatMoney
order by M.cCusName