Question

我坚持制作MySQL查询来解决问题。我试图遍历一个＆＃34; sales＆＃34;我试图按照累计支出总额对客户ID进行排序。

|Customer ID| Purchase price|
10          |1000
10          |1010
20          |2111
42          |9954
10          |9871
42          |6121

如果我总结了客户ID相同的购买价格，我将如何遍历表格？

期待结果如：

Customer ID|Purchase Total
10          |11881
20          |2111
42          |16075

我得：选择客户ID，总和（PurchasePrice）作为SaleTotal，来自销售，其中CustomerID =（从销售中选择不同（CustomerID））订单，由PurchaseTotal asc; 但它没有工作，因为它没有遍历CustomerID，它只是想要单个结果值......

Answer 1

您需要func printPacketInfo(packet: UnsafeMutablePointer<MIDIPacket>){ // print some things print("length", packet.memory.length) print("time", packet.memory.timeStamp) let len = Int(packet.memory.length) withUnsafePointer(&packet.memory.data) { p in let p = UnsafeMutablePointer<UInt8>(p) for i:Int in 0 ..< len { print(i, p[i]) } } }您的客户ID：

GROUP BY

Answer 2

选择CustomerID，sum（PurchasePrice）作为PurchaseTotal FROM sales GROUP BY CustomerID ORDER BY PurchaseTotal ASC;

Answer 3

只需进行一些谷歌搜索，我就找到了一个完全正在做的事情的页面（我想）。我根据您的情况量身定制了以下查询。

SELECT CustomerID, SUM(PurchasePrice) AS PurchaseTotal
FROM sales
GROUP BY CustomerID
ORDER BY PurchaseTotal ASC

Link to Page with Tutorial on SQL Groups

MYSQL - 基于其他列中的公共值的列的SUM

3 个答案: