sql分组函数

Question

我正在使用一个odbc连接到as400，我知道连接字符串是正确的，并且与所有其他查询一起工作时没有任何问题。

那为什么这条SQL语句的工作原理：

select 
    rdqty, 
    alib.rcvshpdt.mbsnodesc, 
    rdauthor, 
    rdtitle, 
    rdediton, 
    ifnull(iecactno,actvty) as actlvl, 
    class, 
    ifnull(ieclp,lp) as cst 
from 
    alib.rcvshpdt 
    left outer join 
    alib.bkmaster on alib.rcvshpdt.mbsnodesc=alib.bkmaster.mbsno 
    left outer join 
    alib.iecostda on alib.rcvshpdt.rcvno=alib.iecostda.rcvno 
    and alib.rcvshpdt.mbsnodesc = alib.iecostda.mbsnodesc 
where 
    alib.rcvshpdt.rcvno='3930697' 
order by 
    actlvl asc 

但只要我试着总结一个控管数量和分组结果如下失败。

select 
    sum(rdqty) as quanity, 
    alib.rcvshpdt.mbsnodesc, 
    rdauthor, 
    rdtitle, 
    rdediton, 
    ifnull(iecactno,actvty) as actlvl, 
    class, 
    ifnull(ieclp,lp) as cst 
from 
    alib.rcvshpdt 
    left outer join 
    alib.bkmaster on alib.rcvshpdt.mbsnodesc=alib.bkmaster.mbsno 
    left outer join 
    alib.iecostda on alib.rcvshpdt.rcvno=alib.iecostda.rcvno 
    and alib.rcvshpdt.mbsnodesc = alib.iecostda.mbsnodesc 
where 
    alib.rcvshpdt.rcvno='3930697' 
group by 
    alib.rcvshpdt.mbsnodesc, rdauthor, rdtitle, rdediton, actlvl, class, cst 
order by 
    actlvl asc 

Answer 1

据我所知，你不能用别名进行分组。尝试改变集团条款直接使用的计算如下所示：

alib.rcvshpdt.mbsnodesc，rdauthor，rdtitle，rdediton，IFNULL（iecactno，actvty）类，IFNULL（ieclp，LP）