Mysql 如何在SQL中生成百分比列？

超级新的SQL在这里

我试图在第三列列出重新交付的订单与总订单的百分比，但我不知道该怎么做（即，对于输出中的第一行，该值应为4%）

这是我的密码：

SELECT DISTINCT WH AS Warehouse,
                count(order_id) AS Orders,
                sum(CASE
                        WHEN is_redelivered=1 THEN 1
                        ELSE 0
                    END) AS Redelivered
FROM
  (SELECT DISTINCT o.id AS order_id,
                   wh.code AS WH,
                   o.initial_delivery_date,
                   date(o.delivered_by) AS delivered_by,
                   if(o.delivered_by>o.initial_delivery_date, 1, 0) AS is_redelivered
   FROM `order` o
   JOIN `order_status` os ON o.id = os.id
   JOIN `warehouse` wh ON o.warehouse_id = wh.id
   WHERE o.created_at BETWEEN '2020-11-22' AND '2020-11-28'
     AND os.status != 'Cancelled') orders
GROUP BY WH

---

如果我没有弄错，您可以：

select 
    wh.code as wh, 
    count(*) as cnt_orders,
    sum(o.delivered_by > o.initial_delivery_date) as cnt_redelivered
    100 * avg(o.delivered_by > o.initial_delivery_date) as percent_redelivered
from `order` o
join `order_status` os on o.id = os.id
join `warehouse` wh on o.warehouse_id = wh.id
where o.created_at between '2020-11-22' and '2020-11-28' and os.status <> 'cancelled'
group by wh.id, wh.code

选择
代码为wh，
将（*）计算为cnt_订单，
作为cnt重新交付的金额（o.交付人>o.初始交付日期）
100*平均值（o.交付日期>o.初始交付日期）作为重新交付百分比
从'order'o
在o.id=os.id上加入'order_status'操作系统
在o.warehouse\u id=wh.id上加入'warehouse'wh
其中o.在“2020-11-22”和“2020-11-28”之间创建了_，且os.状态为“已取消”
按wh.id、wh.code分组

如果您能提供示例数据，那就更好了。哇，太棒了！这完全有效！这让我的问题变得更短！谢谢GMB:）