Question

我有一个存储股票市场数据的数据库。

有一个包含3列的表格： stockId ， date 和 volume

每个交易日都会在表格中插入新数据。

如何获得“过去10个交易日内每只股票的平均交易量”这样的结果？

Answer 1

SELECT SUM(volume)/10 FROM table_name
Where date Between Cast('7/18/13 12:01:01' As DateTime) And Cast('7/08/13 12:01:01' as DateTime)

Answer 2

SELECT AVG(volume) FROM mytable WHERE date >= (CURDATE() - INTERVAL 10 DAY)

修改

最近10天的小组及其平均值。

SELECT AVG(volume) FROM mytable GROUP BY date ORDER BY date DESC LIMIT 10

Answer 3

http://sqlfiddle.com/#!6/c8dbb/4

CREATE TABLE Stocks
    ([StockId] int, [Date] DateTime, [Volume] int)
;

INSERT INTO Stocks
    ([StockId], [Date], [Volume])
VALUES
    (1, GetDate(), 1000),
    (1, GetDate()+1, 2000),
    (1, GetDate()+2, 4000),
    (2, GetDate(), 1000),
    (2, GetDate()+1, 1000),
    (2, GetDate()+2, 500)
;

Select StockId, AVG(Volume) [AverageVolume]
FROM Stocks
WHERE [Date] >= DATEADD(dd, 0, DATEDIFF(dd, 0, GetDate())) - 10
Group by StockId
Order by StockId

Answer 4

我基于Dodecapus的答案，并根据你给出的其他答案的评论。我只是在回答中包含查询，但请查看sqlfiddle以获取数据的工作示例。

http://sqlfiddle.com/#!6/91599/2

SELECT 
    StockId
   ,AVG(Volume) [AverageVolume]
FROM Stocks
WHERE [Date] IN 
(
  SELECT DISTINCT TOP 10 [Date] FROM Stocks ORDER BY [Date] DESC
)
GROUP BY StockId
ORDER BY StockId

仅当每个交易日有至少一只股票的成交量时才会生效。

Answer 5

有趣的小写查询。这是：

SELECT AVG(x.Volume) FROM (SELECT Volume FROM StockTable WHERE Date BETWEEN
DATE_ADD(NOW(), INTERVAL -10 DAY) AND NOW())x

这是我用来构建一个样本表来处理SQLFiddle：

CREATE TABLE StockTable (ID INT PRIMARY KEY AUTO_INCREMENT NOT NULL, Date DATETIME, Volume INT);
INSERT INTO StockTable (Date, Volume) VALUES (DATE_ADD(NOW(), INTERVAL 12 DAY), 1000), (DATE_ADD(NOW(), INTERVAL 1 DAY), 5000),
(DATE_ADD(NOW(), INTERVAL 0 DAY), 3000), (DATE_ADD(NOW(), INTERVAL -11 DAY), 6000), (DATE_ADD(NOW(), INTERVAL -5 DAY), 4000), (DATE_ADD(NOW(), INTERVAL 7 DAY), 9000);

~~以下是运行中查询的SQLFiddle的链接。~~

查询背后的想法：我创建了一个派生表 x，其中只包含过去10天内的卷。然后我计算该表中包含的卷的平均值。瞧！

修改

在阅读完其他答案和评论后，我明确地意识到了你在寻找什么。您希望在过去10天内获得股票市场中每只股票的平均。

我构建了样本表：

CREATE TABLE StockTable (StockId INT NOT NULL, Date DATETIME, Volume INT); INSERT INTO StockTable (StockId, Date, Volume) VALUES (1, DATE_ADD(NOW(), INTERVAL 6 DAY), 1000), (2, DATE_ADD(NOW(), INTERVAL 1 DAY), 5000), (2, DATE_ADD(NOW(), INTERVAL 0 DAY), 3000), (3, DATE_ADD(NOW(), INTERVAL -8 DAY), 6000), (1, DATE_ADD(NOW(), INTERVAL -5 DAY), 4000), (2, DATE_ADD(NOW(), INTERVAL 7 DAY), 9000);

获得结果的查询是：

SELECT StockId, AVG(Volume) FROM StockTable WHERE Date BETWEEN DATE_ADD(NOW(), INTERVAL -10 DAY) AND NOW() GROUP BY StockId

Here是指向运行中查询的SQLFiddle的链接。

获得期间的平均数

5 个答案: