CTE 递归查询填充序列答案

【问题标题】：CTE Recursive Query to fill in a SequenceCTE 递归查询填充序列
【发布时间】：2014-12-30 13:15:53
【问题描述】：

在此 TSQL CTE 中，我正在尝试构建一个发票列表，该列表以递归方式从父版本开始，每张发票一直到第 1 版。

With
  myList
  AS (Select 10000 as INVOICE, 3 as VER
      UNION ALL
      Select 20000 as INVOICE, 5 as VER
      UNION ALL
      Select 30000 as INVOICE, 8 as VER
      UNION ALL
      Select 40000 as INVOICE, 2 as VER)
 ,newList (Invoice, Ver)
  AS (Select
       L1.Invoice
      ,L1.Ver
      from
       myList L1
      UNION ALL
      Select
       L2.Invoice
      ,L2.Ver - 1 Ver
      from
       myList L2
      Join
       newList L3
       on L2.invoice = L3.Invoice and L2.VER = L3.VER
      Where
       L2.Ver > = 1 )
 Select * from newList order by INVOICE, VER desc

“myList”上的选择将为您提供：

Invoice Ver
10000   3
20000   5
30000   8
40000   2

而我希望达到的是：

Invoice Ver
10000   3
10000   2
10000   1
20000   5
20000   4
20000   3
20000   2
20000   1
30000   8
30000   7
30000   6
30000   5
30000   4
30000   3
30000   2
30000   1
40000   2
40000   1

我尝试了很多变化（当然不是正确的！）但我能做的最好的就是只达到第二级......

Invoice Ver
10000   3
10000   2
20000   5
20000   4
30000   8
30000   7
40000   2
40000   1

感谢观看！

【问题讨论】：

标签： sql tsql recursion common-table-expression

【解决方案1】：

你需要有一个递归 CTE，在每个递归调用中需要减少 ver 列

With myList
AS 
(     Select 10000 as INVOICE, 3 as VER
      UNION ALL
      Select 20000 as INVOICE, 5 as VER
      UNION ALL
      Select 30000 as INVOICE, 8 as VER
      UNION ALL
      Select 40000 as INVOICE, 2 as VER
 )
 ,newList (Invoice, Ver)
  AS 
 (
    SELECT INVOICE, VER from myList
    UNION ALL
    SELECT INVOICE, VER-1 FROM newList
    WHERE VER >1
  )
  SELECT * FROM newList order by INVOICE, VER desc

【讨论】：

哈哈 - 以为我正在做你说我需要做的事情。我想微软示例让我失望，因为它的 CTE 的两条腿都引用了锚查询。无论如何，干得好！