相关疑难解决方法(0)

我需要计算一个日期范围内的滚动总和。为了说明，使用AdventureWorks 示例数据库，以下假设语法将完全满足我的需要：

SELECT
    TH.ProductID,
    TH.TransactionDate,
    TH.ActualCost,
    RollingSum45 = SUM(TH.ActualCost) OVER (
        PARTITION BY TH.ProductID
        ORDER BY TH.TransactionDate
        RANGE BETWEEN 
            INTERVAL 45 DAY PRECEDING
            AND CURRENT ROW)
FROM Production.TransactionHistory AS TH
ORDER BY
    TH.ProductID,
    TH.TransactionDate,
    TH.ReferenceOrderID;

遗憾的是，RANGE窗口框架范围目前在 SQL Server 中不允许间隔。

我知道我可以使用子查询和常规（非窗口）聚合编写解决方案：

SELECT 
    TH.ProductID,
    TH.TransactionDate,
    TH.ActualCost,
    RollingSum45 =
    (
        SELECT SUM(TH2.ActualCost)
        FROM Production.TransactionHistory AS TH2
        WHERE
            TH2.ProductID = TH.ProductID
            AND TH2.TransactionDate <= TH.TransactionDate
            AND TH2.TransactionDate >= DATEADD(DAY, -45, TH.TransactionDate)
    )
FROM Production.TransactionHistory AS TH
ORDER BY
    TH.ProductID,
    TH.TransactionDate, …

在跨越 18 个月内跨越 1,000 多个实体的交易数据库中，我想运行一个查询，将每个可能的 30 天期间entity_id按其交易金额的总和和该 30 天内的交易计数进行分组，并且以我可以查询的方式返回数据。经过大量测试，这段代码完成了我想要的大部分内容：

SELECT id, trans_ref_no, amount, trans_date, entity_id,
    SUM(amount) OVER(PARTITION BY entity_id, date_trunc('month',trans_date) ORDER BY entity_id, trans_date ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS trans_total,
    COUNT(id)   OVER(PARTITION BY entity_id, date_trunc('month',trans_date) ORDER BY entity_id, trans_date ROWS BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING) AS trans_count
  FROM transactiondb;

我将在更大的查询中使用类似的结构：

SELECT * FROM (
  SELECT id, trans_ref_no, amount, trans_date, entity_id,
      SUM(amount) OVER(PARTITION BY entity_id, date_trunc('month',trans_date) ORDER BY entity_id, trans_date ROWS BETWEEN UNBOUNDED PRECEDING AND …