一张消费表查可能重复扣费记录的sql

消费时间差一分钟以内，消费额相同
时间是datatime格式
我这样写的有问题
select * from T1TRANSINFO t1 where exists(
select * from T1TRANSINFO t where t.amount in(
select t.amount from T1TRANSINFO t group by t.amount having count(*)>1
) t2 where t1.amount=t2.amount and abs(t1.ttime-t2.ttime)<60
)

select * from (select * from T1TRANSINFO)t1
where t1.cardid not in(
select cardid from T1TRANSINFO
) and

t1.ttime not in(

select ttime from T1TRANSINFO where t1.ttime -ttime<60 )