SQL语句记录

1. sql查找一列中出现次数大于8的记录

select 
  `POID` 
from 
  `orderDetail` 
group by 
  `POID` 
having count(*) >8;

2. SQL查找集合中的记录

select 
  `OID`
from 
  `orderHead`
where 
  `OID` in (
    select 
      `POID`
    from
      `orderDetail`
    group by 
      `POID` 
    having count(*) > 8
);