递归 CTE 查询循环直到满足条件

Question

我正在尝试编写一个查询，它将递归地寻找初始位置或部件号已更改。

有一个 table stktrans 保存任何订单的 IN 和 OUT 交易.

当发送某些东西时 OUT 它会有一个 IN_Nr 可以用来追溯 IN 事务。 OrderNr 将 IN 链接到 OUT

编辑：给定任何 IN_Nr 我希望能够追溯到购买它的原始订单。在下面的 table 中 - TransID 1。但显示事件的完整时间线，例如下面的 table。

传输ID	部分	IN_Nr	OUT_Nr	订单号	类型
8	123-1	232753	232233	888777	输出
7	123-1	232753	空	125707	输入
6	123-1	203944	224789	125707	输出
5	123-1	203944	空	123332	输入
4	123-1	179409	198306	123332	输出
3	123-1	179409	空	111222	输入
2	123-1	176573	171516	111222	输出
1	123-1	176573	空	666000	输入

回溯之间的规律如下图:

目前，我有一个非常非动态的查询，它可以从任何给定的 IN_Nr:

追溯 4 个级别

    DECLARE @IN_Nr INT = 232753
    
    
    ;WITH StkOUT_CTE AS (
            SELECT 
                ST.TransID, 
                ST.Part, 
                ST.IN_Nr, 
                ST.OUT_Nr,
                ST.OrderNr, 
                ST.Type
            FROM 
                StkTrans ST 
            WHERE
                OUT_Nr IS NOT NULL
                AND ST.Type = 'OUT'
    ),
    StkIN_CTE AS (
            SELECT 
                ST.TransID, 
                ST.Part, 
                ST.IN_Nr, 
                ST.OUT_Nr,
                ST.OrderNr, 
                ST.Type
            FROM 
                StkTrans ST 
                INNER JOIN StkOUT_CTE SI ON SI.IN_Nr = ST.IN_Nr
            WHERE
                ST.Type = 'IN'
    )
    SELECT 
           *
      FROM 
      (
              SELECT 
                1 RowOrder, *
              FROM 
              StkOUT_CTE  
              WHERE IN_Nr = @IN_Nr
          UNION
              SELECT 
                2 RowOrder, *
              FROM 
              StkIN_CTE
              WHERE IN_Nr = @IN_Nr
          UNION
            SELECT 3 RowOrder, *
            FROM 
                StkOUT_CTE
            WHERE
                OrderNr = (SELECT OrderNr FROM StkIN_CTE WHERE IN_Nr = @IN_Nr)
          UNION
            SELECT 4 RowOrder, *
            FROM 
                StkIN_CTE
            WHERE
                IN_Nr = (
                    SELECT IN_Nr
                    FROM 
                        StkOUT_CTE
                    WHERE
                        OrderNr = (SELECT OrderNr FROM StkIN_CTE WHERE IN_Nr = @IN_Nr))
        ) ST

要创建类似的设置：

    CREATE TABLE StkTrans (
        TransID INT, 
        Part VARCHAR(25), 
        IN_Nr INT, 
        OUT_Nr INT, 
        OrderNr INT, 
        Type    VARCHAR(3)
    )

    INSERT INTO StkTrans
    (TransID, Part, IN_Nr, OUT_Nr, OrderNr, Type)
    VALUES
    (1, '123-1', 176573, NULL, 666000, 'IN' ),
    (2, '123-1', 176573, 171516, 111222, 'OUT' ),
    (3, '123-1', 179409, NULL, 111222, 'IN' ),
    (4, '123-1', 179409, 198306, 123332, 'OUT' ),
    (5, '123-1', 203944, NULL, 123332, 'IN' ),
    (6, '123-1', 203944, 224789, 125707, 'OUT' ),
    (7, '123-1', 232753, NULL, 125707, 'IN' ),
    (8, '123-1', 232753, 232233, 888777, 'OUT' )

任何可能为我指明如何递归使用 CTE 的正确方向的指导都很棒！

Answer 1

字里行间，也许这就是您想要的？

WITH rCTE AS(
    SELECT *,
           1 AS Iteration
    FROM dbo.StkTrans ST
    WHERE ST.IN_Nr = '232753'
      AND ST.[Type] = 'IN'
    UNION ALL
    SELECT STi.*,
           r.Iteration + 1
    FROM dbo.StkTrans STo
         JOIN dbo.StkTrans STi ON STo.IN_Nr = STi.IN_Nr                     
         JOIN rCTE r ON STo.OrderNr = r.OrderNr
    WHERE STo.[Type] = 'Out'
      AND STi.[Type] = 'In')
SELECT TOP (1) TransID
FROM rCTE
ORDER BY ROW_NUMBER() OVER (ORDER BY Iteration DESC);

db<>fiddle

---

编辑： 也许这就是您所追求的。我现在也对 rCTE 中的第一个数据集进行参数化，以便于针对其他值进行测试。

DECLARE @IN_Nr int = 232753;

WITH rCTE AS(
    SELECT V.*,
           1 AS Iteration
    FROM dbo.StkTrans STo
         JOIN dbo.StkTrans STi ON STo.IN_Nr = STi.IN_Nr      
         CROSS APPLY (VALUES(STo.TransID,STo.Part,STo.IN_Nr,STo.OUT_Nr,STo.OrderNr,STo.[Type]),
                            (STi.TransID,STi.Part,STi.IN_Nr,STi.OUT_Nr,STi.OrderNr,STi.[Type]))V(TransID,Part,IN_Nr,OUT_Nr,OrderNr,[Type])
    WHERE STo.IN_Nr = @IN_Nr
      AND STo.[Type] = 'OUT'
      AND STi.[Type] = 'In'
    UNION ALL
    SELECT V.*,
           r.Iteration + 1
    FROM dbo.StkTrans STo
         JOIN dbo.StkTrans STi ON STo.IN_Nr = STi.IN_Nr                     
         JOIN rCTE r ON STo.OrderNr = r.OrderNr
                    AND r.[Type] = 'In'
         CROSS APPLY (VALUES(STo.TransID,STo.Part,STo.IN_Nr,STo.OUT_Nr,STo.OrderNr,STo.[Type]),
                            (STi.TransID,STi.Part,STi.IN_Nr,STi.OUT_Nr,STi.OrderNr,STi.[Type]))V(TransID,Part,IN_Nr,OUT_Nr,OrderNr,[Type])
    WHERE STo.[Type] = 'Out'
      AND STi.[Type] = 'In')
SELECT TransID,
       Part,
       IN_Nr,
       OUT_Nr,
       OrderNr,
       [Type]
FROM rCTE
ORDER BY TransID DESC;

db<>fiddle