您好！能请您看看我的代码嘛(//-//)我很疑惑，我倒数第二行的筛选条件“where refund_rate<=0.5”会把refund_rate=0.333变成了0.000；而且如果这个筛选条件变成“payment_rate>1”，它就会把payment_rate=0.750变成了1.000。请问您知道我是哪里出了错误嘛？非常感谢！！ select * from (select product_id, round(click/shown,3) as ctr, round(if(click=0,0,cart/click),3) as cart_rate, round(if(cart=0,0,pay/cart),3) as payment_rate, round(if(pay=0,0,refund/pay),3) as refund_rate from (select product_id, count(1) as shown, sum(if_click) as click, sum(if_cart) as cart, sum(if_payment) as pay, sum(if_refund) as refund from tb_user_event where substring(event_time,1,7)='2021-10' group by product_id)a)b where refund_rate<=0.5 order by product_id