需要从递归表生成视图

Question

如果有人可以提供帮助，我会陷入困境：  我的桌子看起来如下

请注意：可以有n个级别，但如果您在某个级别添加项目，则无法创建子级别。

从上面我想要产生这种观点：

即使它可能在c＃中请指出。我怎么能这样做？

Answer 1

应该如此简单：

CREATE VIEW YourViewName
AS
    WITH Tree (ID, [NAME], PARENT_ID, Depth, Sort) AS
    (
        SELECT ID, [NAME], PARENT_ID, 0 AS Depth, CONVERT(varchar(255), [Name]) AS Sort         
        FROM Category
        WHERE PARENT_ID = 0
        UNION ALL
        SELECT CT.ID, CT.[NAME], CT.PARENT_ID, Parent.Depth + 1 AS Depth, 
        CONVERT(varchar(255), Parent.Sort + ' | ' + CT.[NAME]) AS Sort
        FROM Category CT
        INNER JOIN Tree as Parent ON Parent.ID = CT.PARENT_ID
    )

    -- HERE IS YOUR TREE, Depths gives you the level starting with 0 and Sort is the Name based path
    SELECT ID, [NAME], PARENT_ID, Depth, Sort FROM Tree
GO

Answer 2

我喜欢递归节目

fanout