Question

这是一个巨大的怪物，它进入SP所以变量可用：

SELECT OwnerName, SUM(AmountPaid) AS Paid, SUM(AmountOwedComplete) AS Owed, SUM(AmountOwedThisMonth) AS OwedMonth,
    SUM(PaidForPast) AS PaidPast, SUM(PaidForPresent) AS PaidPresent, SUM((AmountPaid - PaidForPast - PaidForPresent)) AS PaidFuture, [Description] FROM (
    SELECT OwnerName, AmountPaid, AmountOwedComplete, AmountOwedThisMonth, PaidForPast, [Description],
        (SELECT CASE WHEN (AmountPaid - PaidForPast) < ABS(AmountOwedThisMonth) THEN AmountPaid - PaidForPast
            ELSE ABS(AmountOwedThisMonth) END) AS PaidForPresent
    FROM (
        SELECT OwnerName, AmountPaid, AmountOwedTotal - AmountPaid AS AmountOwedComplete,
            AmountOwedThisMonth, 
            (SELECT CASE WHEN (AmountPaid < ABS((AmountOwedTotal - AmountPaid)) + AmountOwedThisMonth)
                THEN AmountPaid ELSE ABS((AmountOwedTotal - AmountPaid)) + AmountOwedThisMonth END) AS PaidForPast, 
            Description, TransactionDate
         FROM (
            SELECT DISTINCT t.TenantName, p.PropertyName, ISNULL(p.OwnerName, 'Uknown') AS OwnerName, (
                SELECT SUM(Amount) FROM tblTransaction WHERE 
                    Amount > 0 AND TransactionDate >= @StartDate AND TransactionDate <= @EndDate
                    AND TenantID = t.ID AND TransactionCode = trans.TransactionCode
            ) AS AmountPaid, (
                SELECT SUM(Amount) FROM tblTransaction WHERE 
                    tblTransaction.TransactionCode = trans.TransactionCode AND tblTransaction.TenantID = t.ID
            )  AS AmountOwedTotal, (
                SELECT SUM(Amount) FROM tblTransaction WHERE  tblTransaction.TransactionCode = trans.TransactionCode AND tblTransaction.TenantID = t.ID
                    AND Amount < 0 AND TransactionDate >= @StartDate AND TransactionDate <= @EndDate
            ) AS AmountOwedThisMonth, code.Description, trans.TransactionDate FROM tblTransaction trans 
            LEFT JOIN tblTenantTransCode code ON code.ID = trans.TransactionCode
            LEFT JOIN tblTenant t ON t.ID = trans.TenantID
            LEFT JOIN tblProperty p ON t.PropertyID  = p.ID
            WHERE trans.TransactionDate >= @StartDate AND trans.TransactionDate <= @EndDate AND trans.Amount > 0
        ) q
    ) q2
)q3
GROUP BY OwnerName, Description

这就是它的作用。它会访问所有租户并获得他们本月支付的费用，以及他们所欠的一切。然后计算以前的费用，本月和未来费用的支付额。然后根据收费说明和业主名称对它们进行汇总。

看起来很糟糕，我想知道是否有一些我可以使用的捷径。

Answer 1

这里的杀手是PaidForPast（和派生PaidForPresent）计算，似乎是在试图表明租客是否已经支付了他的余额（如果我理解正确的话 - 这并不容易）。这个计算必须按照每一笔支付交易执行，并依赖于从整个租户历史派生的另一个聚合，这保证了O（n ^ 2）操作。

对你的数据库来说，这是一个残酷，残酷的事情，虽然我可能会让你的查询看起来更漂亮，但只要你被迫生产，你就无法从性能问题中解脱出来。基于此查询所暗示的特定可用数据集的信息。

您所拥有的不是重构/优化问题，而是严重的设计问题。实际上你有两个问题。较小的问题是您正在将业务逻辑编码到数据层中;更大的问题是系统的设计并不是为了跟踪它实际需要的所有信息。

您在此查询中生成的信息基本上所有应保存在某种A / R历史记录表中，该记录表记录每个事务的这些聚合/统计信息。该表可由应用程序本身或tblTransaction表上的触发器维护。

可能不是你正在寻找的答案，但当我意识到不可能删除PaidForXYZ嵌套时，我实际上已经进行了重构的一半。

实际上，生成这些结果的最快方法可能是使用游标，因为这样您就可以使用部分聚合并将其转换为O（n）操作。但是你真的希望游标在没有过滤器的整个事务表上运行吗？

更新

如果你真的不关心性能而只想清理它以便更容易阅读/维护，那么这就是我能想出的最好使用一些CTE：

;WITH Transactions_CTE AS
(
    SELECT
        TenantID,
        TransactionCode,
        Amount,
        CASE
            WHEN Amount > 0 AND TransactionDate BETWEEN @BeginDate AND @EndDate
                THEN Amount
            ELSE 0
        END AS AmountPaid,
        CASE
            WHEN Amount < 0 AND TransactionDate BETWEEN @BeginDate AND @EndDate
                THEN Amount
            ELSE 0
        END AS AmountOwed,
    FROM tblTransaction
),
Summary_CTE AS
(
    SELECT
        t.PropertyID,
        tr.TransactionCode,
        SUM(tr.Amount) AS CumulativeBalance,
        SUM(tr.AmountPaid) AS CurrentPaid,
        SUM(tr.AmountOwed) AS CurrentOwed
    FROM Transactions_CTE tr
    INNER JOIN tblTenant t ON tr.TenantID = t.ID
    GROUP BY t.PropertyID, tr.TransactionCode
),
Past_CTE AS
(
    SELECT
        PropertyID, TransactionCode,
        CumulativeBalance, CurrentPaid, CurrentOwed,
        CASE
            WHEN CurrentPaid < 
              ABS(CumulativeBalance - CurrentPaid) + CurrentOwed
            THEN CurrentPaid
            ELSE ABS(CumulativeBalance - CurrentPaid) + CurrentOwed
        END AS PaidForPast
    FROM Summary_CTE
),
Present_CTE AS
(
    SELECT
        PropertyID, TransactionCode,
        CumulativeBalance, CurrentPaid, CurrentOwed,
        PaidForPast,
        CASE
            WHEN (CurrentPaid - PaidForPast) < ABS(CurrentOwed)
            THEN CurrentPaid - PaidForPast
            ELSE ABS(CurrentOwed)
        END AS PaidForPresent
     FROM Past_CTE
)
SELECT
    ISNULL(p.OwnerName, 'UNKNOWN') AS OwnerName,
    c.[Description],
    CumulativeBalance, CurrentPaid, CurrentOwed,
    CumulativeBalance - CurrentPaid AS CumulativeOwed,
    PaidForPast, PaidForPresent,
    CurrentPaid - PaidForPast - PaidForPresent AS PaidForFuture,
    [Description]
FROM Present_CTE s
LEFT JOIN tblProperty p ON p.ID = s.PropertyID
LEFT JOIN tblTenantTransCode c ON c.ID = s.TransactionCode

你可以通过完整地写出整个PaidForXYZ表达式来消除最后两个CTE，而不是在另一个上面构建一个，但IMO最终会使它更少可读，我很确定优化器会解决它并将其全部映射到表达式而不是子查询。

另外，我必须说所有这些ABS块让我怀疑。我不知道这里发生了什么的细节，但感觉就像那些被用来代替否定运算符，可能是一个应该在上游进一步使用（即将借方或贷方转换为负数）和这可能会导致一些微妙的错误。

Answer 2

首先，学习格式化SQL，以便你（和我）可以阅读它：

SELECT OwnerName, 
       SUM(AmountPaid) AS Paid, 
       SUM(AmountOwedComplete) AS Owed, 
       SUM(AmountOwedThisMonth) AS OwedMonth,
       SUM(PaidForPast) AS PaidPast, 
       SUM(PaidForPresent) AS PaidPresent, 
       SUM((AmountPaid - PaidForPast - PaidForPresent)) AS PaidFuture, 
       [Description] 
  FROM (SELECT OwnerName, 
               AmountPaid, 
               AmountOwedComplete, 
               AmountOwedThisMonth, 
               PaidForPast, 
               [Description],
               (SELECT CASE WHEN (AmountPaid - PaidForPast) < ABS(AmountOwedThisMonth) 
                            THEN AmountPaid - PaidForPast
                       ELSE ABS(AmountOwedThisMonth) END) AS PaidForPresent
          FROM (SELECT OwnerName, 
                       AmountPaid, 
                       AmountOwedTotal - AmountPaid AS AmountOwedComplete,
                       AmountOwedThisMonth, 
                       (SELECT CASE WHEN (AmountPaid < ABS((AmountOwedTotal - AmountPaid)) + AmountOwedThisMonth)
                                    THEN AmountPaid 
                               ELSE ABS((AmountOwedTotal - AmountPaid)) + AmountOwedThisMonth END) AS PaidForPast,     
                               Description, 
                               TransactionDate
                          FROM (SELECT DISTINCT 
                                       t.TenantName, 
                                       p.PropertyName, 
                                       ISNULL(p.OwnerName, 'Uknown') AS OwnerName, 
                                       (SELECT SUM(Amount) 
                                          FROM tblTransaction 
                                         WHERE Amount > 0 
                                           AND TransactionDate >= @StartDate 
                                           AND TransactionDate <= @EndDate
                                           AND TenantID = t.ID 
                                           AND TransactionCode = trans.TransactionCode) AS AmountPaid, 
                                       (SELECT SUM(Amount) 
                                          FROM tblTransaction 
                                         WHERE tblTransaction.TransactionCode = trans.TransactionCode 
                                           AND tblTransaction.TenantID = t.ID)  AS AmountOwedTotal, 
                                       (SELECT SUM(Amount) 
                                          FROM tblTransaction 
                                         WHERE tblTransaction.TransactionCode = trans.TransactionCode 
                                           AND tblTransaction.TenantID = t.ID
                                           AND Amount < 0 
                                           AND TransactionDate >= @StartDate 
                                           AND TransactionDate <= @EndDate) AS AmountOwedThisMonth, 
                                       code.Description, 
                                       trans.TransactionDate 
                                  FROM tblTransaction trans 
                                  LEFT JOIN tblTenantTransCode code ON code.ID = trans.TransactionCode
                                  LEFT JOIN tblTenant t ON t.ID = trans.TenantID
                                  LEFT JOIN tblProperty p ON t.PropertyID  = p.ID
                                 WHERE trans.TransactionDate >= @StartDate 
                                   AND trans.TransactionDate <= @EndDate 
                                   AND trans.Amount > 0) q
               ) q2
       ) q3
 GROUP BY OwnerName, Description;

其次，确保您拥有正确的索引 - 您需要能够读取SQL才能执行此操作。

Answer 3

你对架构有什么发言权吗？就目前而言，看起来您正试图从业务数据存储生成报告，该报告本质上是事务性的。在许多高容量方案中，创建一个称为决策支持数据库的规范较小的模式并不罕见，您可以在特定的时间间隔内复制/汇总事务数据。然后，您可以针对DSS编写非常简单的查询，同时您的高度标准化的ODS继续发挥作用。

帮我重构这个查询的怪物

3 个答案:

更新