按日期顺序更新表

Posted 2023-03-31

【中文标题】按日期顺序更新表

【英文标题】：Updating a table in date order

【发布时间】：2014-06-03 11:16:47

【问题描述】：

如何格，我有一个日期字段 TransactionDate，某些列值依赖于以前的值，我如何遍历表格以按日期顺序更新。

我尝试了一些方法，但一直遇到“ORDER BY 子句在视图、内联函数、派生表、子查询和公用表表达式中无效，除非还指定了 TOP 或 FOR XML。”

我有想要重新处理的日期范围，更改旧值意味着重新计算新值。

UPDATE M
SET M.AvgGain = CASE WHEN M.Price > Previous.Price THEN ( ISNULL( Previous.AvgGain * 13.0, 0 ) + ( M.Price - Previous.Price )) / 14.0 ELSE  ( ISNULL( Previous.AvgGain * 13.0, 0 ) / 14.0 )END
FROM SalesData M
JOIN SalesData AS Previous ON ( SELECT TOP 1 PK FROM SalesData WHERE AbbrevID = M.AbbrevID AND TransactionDate < M.TransactionDate ORDER BY TransactionDate DESC) = Previous.PK
WHERE M.AbbrevID IN ( SELECT PK FROM SalesData  WHERE AbbrevID = ( SELECT PK FROM SalesPeople WHERE Abbreviation = 'Fred') ) AND TransactionDate BETWEEN '1996-02-23' and '1996-05-08'

当我将 TransactionDate 的订单插入到 Join 中时，我很生气

【问题讨论】：

请编辑您的问题以提供示例数据和您想要做什么。否则，你的问题太模糊了。

你能显示你写的查询吗？

查询中的括号没有正确关闭，最后一个AND是用于最外层查询还是内层查询？

最后一个And是在正确的地方，但你是对的，最后一个额外的括号，我会修改。

【参考方案1】：

如果您需要一次迭代一行，我可能会使用 cursor：

DECLARE @c_mem INT -- for example some numbeer of day, ie the calcuation you need to make from previous rows
SET @c_mem = 0 -- some initial value

DECLARE db_cursor CURSOR FOR  
SELECT [your_table_UID_field]
FROM [your_table_name]
ORDER BY TransactionDate

OPEN db_cursor  
FETCH NEXT FROM db_cursor INTO @c_uid  

WHILE @@FETCH_STATUS = 0  
BEGIN  
       SET @c_mem=[some calculation based on c_mem itself and the current transac date]
       UPDATE [your_table_name]
       SET TransactionDate=[some calculation based on @c_mem, eg transac date + c_mem days]
       WHERE [your_table_UID_field]=@c_uid;

       FETCH NEXT FROM db_cursor INTO @c_uid  
END  

CLOSE db_cursor  
DEALLOCATE db_cursor 

这是你要找的吗？

【参考方案2】：

试试CROSS APPLY

UPDATE    M
    SET M.AvgGain = CASE WHEN M.Price > Previous.Price THEN 
                        ( ISNULL( Previous.AvgGain * 13.0, 0 ) + ( M.Price - Previous.Price )) / 14.0 
                    ELSE  
                        ( ISNULL( Previous.AvgGain * 13.0, 0 ) / 14.0 )
                    END
FROM    SalesData AS M
        CROSS APPLY (
            SELECT    TOP 1 AvgGain, Price
            FROM      SalesData
            WHERE     AbbrevID = M.AbbrevID AND TransactionDate < M.TransactionDate 
            ORDER BY TransactionDate DESC
        ) AS Previous
WHERE    M.AbbrevID IN ( 
                    SELECT     PK 
                    FROM     SalesData  
                    WHERE     AbbrevID = ( SELECT PK FROM SalesPeople WHERE Abbreviation = 'Fred')      
                )
        AND TransactionDate BETWEEN '1996-02-23' and '1996-05-08' 

【参考方案3】：

在 SQL server SQL2005+ 中，您可以通过使用 'with' 和 'over' 来使用更新表 'order by'，如下所示：

With XYX As
(
  SELECT id,Field2, ROW_NUMBER() 
           OVER (ORDER BY YourDateField DESC) AS RN
  FROM YourTable
)
UPDATE XYX SET Field2=RN

reference