alter table 表 add id int identity goselect a.a,a.b,a.c from 表 a,(select id=min(id) from 表 group by a)b where a.id=b.id goalter table 表 drop column id
--如果不改原表,则用临时表 select id=identity(int),a,b,c into #t from 表 select a.a,a.b,a.c from #t a,(select id=min(id) from #t group by a)b where a.id=b.id drop table #t
我用了这个方法: select a,max(b) as b ,max(c) as c from yourtable group by a但是为何用 rs.recordcount 返回的是 -1 ?? 怎么统计选取出来的记录总数?
select count(tb.a) as recordcount from (select a,max(b) as b ,max(c) as c from yourtable group by a ) tb
select max(a),b,c from ……
zjcxc(邹建) 的答案不正确 其实LoveSQL(努力奋斗ing)的 :select a,max(b) as b ,max(c) as c from yourtable group by a应该可以达到要求!建议给分因为楼主的要求就是列a必须唯一,这样肯定是要去掉一些记录,而如何去掉一些记妹,也没要求 所以用max() 或 min()
goselect a.a,a.b,a.c
from 表 a,(select id=min(id) from 表 group by a)b
where a.id=b.id
goalter table 表 drop column id
select id=identity(int),a,b,c into #t from 表
select a.a,a.b,a.c
from #t a,(select id=min(id) from #t group by a)b
where a.id=b.id
drop table #t
select a,max(b) as b ,max(c) as c from yourtable group by a但是为何用 rs.recordcount 返回的是 -1 ??
怎么统计选取出来的记录总数?
) tb
其实LoveSQL(努力奋斗ing)的
:select a,max(b) as b ,max(c) as c from yourtable group by a应该可以达到要求!建议给分因为楼主的要求就是列a必须唯一,这样肯定是要去掉一些记录,而如何去掉一些记妹,也没要求
所以用max() 或 min()