关于计算列中同值记录条数的sql

比如表A
id name regdate
用sql求出一共有多少name相同的人，
再写一个语句，把name相同的人存储到B表 ，字段和A一样；
最后一个语句：A中name相同的记录，只留下注册时间最早的，其它删除

一楼的答案估计够呛，
一问：
select count(name) from A group by name having count(name)>1
二问：
select * into B from A group by name having count(name)>1
三问：
select id,name,min(regdate) into temp_table from A group by name,id,redate having count(name)>1
drop table A
select * into A from temp_table
drop table temp_table

用sql求出一共有多少name相同的人 select count(name) from A having count(name)>1 把name相同的人存储到B表 ，字段和A一样 insert into b select name from A having count(name)>1 A中name相同的记录，只留下注册时间最早的，其它删除 select * from A where ID in ((select v.id from (select max(getdate()-regdate),ID from A having count(name)>1)v)t