请教一个关于informix语句的问题

field

情况是这样的,有一个表有以下字段:
zh,fse,rq
其中有很多记录zh字段是相同的,我只想取出其中rq最大的那条记录的fse,请教这个语句如何写?

wenlq

try
select unique zh from tab into temp tmpzh;
select a.* from tab a,tmpzh b   
where  a.zh = b.zh and rq = ( select max( rq ) from tab where zh = b.zh ) ;

shanshl

select tb1.fse
from tbname tb1
where tb1.rq=(select max(tb2.rq) from tbname tb2 where tb1.zh=tb2.zh)
这样应该可以吧

john_student

1. 
   
2. select zh, max(rq) as maxrq
   
3. from tab
   
4. group by zh
   
5. into temp tab_tmp ;
   
6. select a.zh, a.rq, a.fse
   
7. from tab a, tab_tmp b
   
8. where a.zh = b.zh
   
9. and a.rq = b.maxrq ;
   

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