摘要： 用not exists 代替not inselect * from tsp_product p where not exists(select 'X' from tsp_orderitem i where p.id=i.product_id)select * from tsp_product p where id not in(select product_id from tsp_orderitem i where p.id=i.product_id)用exists 代替inselect * from tsp_product p where p.id in(select pro 阅读全文