MySQL 不從 NOT IN 函數返回值

Question

我目前正在嘗試編寫一個查詢，顯示至少有 5 個訂單的客戶和沒有訂單的客戶。 訂單在他們自己的表中進行跟蹤，為了找到有 0 個訂單的客戶，我們必須找到不在訂單中的客戶。 下面是我嘗試使用的查詢，它為零訂單返回同一個客戶 5 次。

with t1 as
 (select o.customerNumber, c.customerName, count(o.orderNumber) as FiveOrders
 from orders o join customers c on (o.customerNumber = c.customerNumber)
 group by o.customerNumber having count(o.orderNumber) = 5),
 t2 as
 (select distinct o.customerNumber, c.customerName, count(o.orderNumber) as NoOrders
 from orders o join customers c on (o.customerNumber = c.customerNumber)
 group by c.customerNumber not in(select customerNumber from orders))
 select distinct t1.customerNumber as FiveOrderNumber, t1.customerName as FiveOrderName,
 t2.customerNumber as NoOrderNumber, t2.customerName as NoOrderName
 from t1 join t2
 order by NoOrderName;

感謝任何和所有幫助！

Answer 1

如果錯誤在第二個表中只，我認為這是與使用條件有NOT IN沒有任何邏輯比較后，我覺得你可以很容易地獲得更多想要的結果：

select distinct customerNumber, customerName, "0" as NoOrders 
from customers 
where customerNumber not in (Select customerNumber from orders)

如果group by很重要，您可以像在代碼中一樣使用它。

Answer 2

Zero或five可以與LEFT JOIN一起計算

select c.customerNumber, max(c.customerName) customerName, count(o.orderNumber) as FiveOrdersOrZero
from customers c
left join orders o on o.customerNumber = c.customerNumber
group by c.customerNumber 
having count(o.orderNumber) in ( 0, 5 )
order by FiveOrdersOrZero