SQL 列的服务器层次总和

Question

我按照图表设计了数据库。

Category table是自引用父子关系
Budget 将为每个类别定义所有类别和金额
Expense table 将包含已花费金额的类别的条目（考虑此 table 中的 Total 列）。

我想编写 select 语句来检索包含以下列的数据集：

ID   
CategoryID   
CategoryName   
TotalAmount (Sum of Amount Column of all children hierarchy From BudgetTable  )   
SumOfExpense (Sum of Total Column of Expense  all children hierarchy from expense table)

我尝试使用 CTE，但无法生成任何有用的东西。提前感谢您的帮助。 :)

更新

我只是为了合并和简化数据，我用下面的查询创建了一个视图。

SELECT        
    dbo.Budget.Id, dbo.Budget.ProjectId, dbo.Budget.CategoryId, 
    dbo.Budget.Amount, 
    dbo.Category.ParentID, dbo.Category.Name, 
    ISNULL(dbo.Expense.Total, 0) AS CostToDate
FROM
    dbo.Budget 
INNER JOIN
    dbo.Category ON dbo.Budget.CategoryId = dbo.Category.Id 
LEFT OUTER JOIN
    dbo.Expense ON dbo.Category.Id = dbo.Expense.CategoryId

基本上应该会产生这样的结果。

Answer 1

经过大量研究并使用测试数据，我能够从层次结构的底部开始获得运行总数。

解决方案由两个步骤组成。

创建一个 scalar-valued 函数来决定一个 categoryId 是另一个 categoryId 的直接子代还是间接子代。这是在第一个code-snippet中给出的。请注意，为此使用了递归查询，因为这是在 SQL 服务器中处理层次结构的最佳方法。
编写运行总计查询，该查询将根据您对所有类别的要求给出总计。如果您想对此查询进行过滤，可以按类别进行过滤。第二个代码片段提供了这个查询。

Scalar-valued 判断子类别是另一个类别的直接或间接子类别的函数

CREATE FUNCTION dbo.IsADirectOrIndirectChild(
               @childId int, @parentId int)
RETURNS int
AS
BEGIN

    DECLARE @isAChild int;
    WITH h(ParentId, ChildId)
    -- CTE name and columns
         AS (
         SELECT TOP 1 @parentId, @parentId
         FROM dbo.Category AS b
         UNION ALL
         SELECT b.ParentId, b.Id AS ChildId
         FROM h AS cte
              INNER JOIN
              Category AS b
              ON b.ParentId = cte.ChildId AND
                 cte.ChildId IS NOT NULL)
         SELECT @isAChild = ISNULL(ChildId, 0)
         FROM h
         WHERE ChildId = @childId AND
               ParentId <> ChildId
         OPTION(MAXRECURSION 32000);
    IF @isAChild > 0
    BEGIN
        SET @isAChild = 1;
    END;
    ELSE
    BEGIN
        SET @isAChild = 0;
    END;
    RETURN @isAChild;
END;
GO

从层次结构底部开始查询运行总数

SELECT c.Id AS CategoryId, c.Name AS CategoryName,
(
    SELECT SUM(ISNULL(b.amount, 0))
    FROM dbo.Budget AS b
    WHERE dbo.IsADirectOrIndirectChild( b.CategoryId, c.Id ) = 1 OR
          b.CategoryId = c.Id
) AS totalAmount,
(
    SELECT SUM(ISNULL(e.total, 0))
    FROM dbo.Expense AS e
    WHERE dbo.IsADirectOrIndirectChild( e.CategoryId, c.Id ) = 1 OR
          e.CategoryId = c.Id
) AS totalCost
FROM dbo.Category AS c;

Answer 2

这是一个有趣的问题。我将使用 hierarchyid 来解决它。一、设置：

USE tempdb;
IF OBJECT_ID('dbo.Hierarchy') IS NOT NULL
    DROP TABLE dbo.[Hierarchy];

CREATE TABLE dbo.Hierarchy 
(
    ID INT NOT NULL PRIMARY KEY,
    ParentID INT NULL,
        CONSTRAINT [FK_parent] FOREIGN KEY ([ParentID]) REFERENCES dbo.Hierarchy([ID]),
    hid HIERARCHYID,
    Amount INT NOT null
);

INSERT INTO [dbo].[Hierarchy]
        ( [ID], [ParentID], [Amount] )
VALUES  
    (1, NULL, 100 ),
    (2, 1, 50),
    (3, 1, 50),
    (4, 2, 58),
    (5, 2, 7),
    (6, 3, 10),
    (7, 3, 20)
SELECT * FROM dbo.[Hierarchy] AS [h];

接下来，使用适合 hiearchyid 的值更新 hid 列。我将为此使用沼泽标准递归 cte

WITH cte AS (
    SELECT  [h].[ID] ,
            [h].[ParentID] ,
            CAST('/' + CAST(h.[ID] AS VARCHAR(10)) + '/' AS VARCHAR(MAX)) AS [h],
            [h].[hid]
    FROM    [dbo].[Hierarchy] AS [h]
    WHERE   [h].[ParentID] IS NULL

    UNION ALL

    SELECT  [h].[ID] ,
            [h].[ParentID] ,
            CAST([c].[h] + CAST(h.[ID] AS VARCHAR(10)) + '/' AS VARCHAR(MAX)) AS [h],
            [h].[hid]
    FROM    [dbo].[Hierarchy] AS [h]
    JOIN    [cte] AS [c]
            ON [h].[ParentID] = [c].[ID]
)
UPDATE [h]
SET hid = [cte].[h]
FROM cte
JOIN dbo.[Hierarchy] AS [h]
    ON [h].[ID] = [cte].[ID];

至此，大功告成，你想要的结果几乎是轻而易举得到：

SELECT p.id, SUM([c].[Amount])
FROM dbo.[Hierarchy] AS [p]
JOIN [dbo].[Hierarchy] AS [c]
    ON c.[hid].IsDescendantOf(p.[hid]) = 1
GROUP BY [p].[ID];

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