如何計算超過1個訂單的用戶？

我正在研究一個MySQL數據庫，我需要查詢數據庫並找出具有多個訂單的用戶。我嘗試過使用COUNT（），但我無法正確理解它。你能解釋一下正確的方法嗎？如何計算超過1個訂單的用戶？

這裏是我的表：

用戶

+-------------+----------+------------------+------------+ 
| userID  | fName | email   | phone  | 
+-------------+----------+------------------+------------+ 
| adele012 | Adele | [email protected] || 
| ana022  | Anna  | [email protected] | 0228374847 | 
| david2012 | David | [email protected] | 902849302 | 
| jefAlan  | Jeffery | [email protected] | 0338473837 | 
| josquein | Joseph | [email protected],com | 0098374678 | 
| jweiz  | John  | [email protected] | 3294783784 | 
| jwick123 | John  | [email protected] | 0998398390 | 
| kenwipp  | Kenneth | [email protected] | 0112938394 | 
| mathCler | Maththew | [email protected] | 0238927483 | 
| natalij2012 | Natalie | [email protected]  || 
+-------------+----------+------------------+------------+

訂單

+---------+------------+-------------+-------------+ 
| orderID | date  | User_userID | orderStatus | 
+---------+------------+-------------+-------------+ 
|  1 | 2012-01-10 | david2012 | Delivered | 
|  2 | 2012-01-15 | jweiz  | Delivered | 
|  3 | 2013-08-15 | david2012 | Delivered | 
|  4 | 2013-03-15 | natalij2012 | Delivered | 
|  5 | 2014-03-04 | josquein | Delivered | 
|  6 | 2014-01-15 | jweiz  | Delivered | 
|  7 | 2014-02-15 | josquein | Delivered | 
|  8 | 2015-10-12 | jwick123 | Delivered | 
|  9 | 2015-02-20 | ana022  | Delivered | 
|  10 | 2015-11-20 | kenwipp  | Processed | 
+---------+------------+-------------+-------------+

來源

2015-11-22 Isuru Pathirana

select user_userID, count(*) as orders_count from orders 
group by user_userID having orders_count > 1

如果y ou想要從用戶表中獲得更多數據，您可以執行：

select * from user where user_id in (
    select user_userID as orders_count from orders 
    group by user_userID having orders_count > 1 
)

來源

2015-11-22 23:29:37

這是正確的目標。它也可以被寫爲'select_user_userID from orders group by user_userID having count（*）> 1'。另外，根據OP的數據集大小比較'where exists'與'where user_id in'的速度是有益的 – zedfoxus

我忘記在我的初始查詢中使用GROUP BY。第一個工作正常。但是，當我試圖獲得更多的信息使用子查詢它失敗，錯誤錯誤1054（42S22）：'IN/ALL/ANY子查詢中的未知列'user_ID' –

這對我有用 SELECT * FROM User WHERE userID IN （ SELECT User_userID as userID FROM Orders GROUP BY User_userID HAVING count（*）> 1 ）; –

如何計算超過1個訂單的用戶？

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