訂單日期範圍內的SQL客戶訂單查詢

Question

我試圖得到一份訂單報告，不僅返回客戶訂單總數，還返回三個附加字段，其中包含第一個和最後一個訂單的日期以及範圍第一個和最後爲了

下面的查詢

之間

SELECT customers.name, 
    customers.customer_id, 
    COUNT(orders.order_id) AS Orderscount 
    FROM customers 
    JOIN orders ON customers.customer_id = orders.customer_id 
    GROUP BY customers.name, 
      customers.customer_id      
     HAVING Orderscount >= 2 
     ORDER BY Orderscount DESC 

（以天爲單位）返回名稱，CUSTOMER_ID和訂單總數的計數表。

問題是，如何添加此查詢以獲取first_order，last_order和兩者之間的日期範圍的日期？

我正在使用SQLite。

Answer 1

使用MIN和MAX獲得第一和最後訂購日期和julianday()計算範圍：

SELECT customers.name, 
    customers.customer_id, 
    COUNT(orders.order_id) AS Orderscount, 
    MIN(col_name) AS firstOrder, 
    MAX(col_name) AS lastOrder, 
    ROUND(julianday(MAX(col_name)) - julianday(MIN(col_name))) AS range 
FROM customers 
JOIN orders ON customers.customer_id = orders.customer_id 
GROUP BY customers.name, 
     customers.customer_id      
HAVING Orderscount >= 2 
ORDER BY Orderscount DESC