MSSQL獲取子節點的遞歸父標題

Question

我有一張桌子（下面的結構和樣本數據）

declare @table table
(
PrimaryID BIGINT,
ParentID BIGINT NULL,
Title NVARCHAR(100) NULL,
HierID HIERARCHYID
)

INSERT INTO @table VALUES (100, NULL, 'Root', 0x52C0)
INSERT INTO @table VALUES (101, 100, 'Folder', 0x52D6)
INSERT INTO @table VALUES (102, 101, 'SubFolder', 0x52D6F0)
INSERT INTO @table VALUES (103, 102, 'Document', 0x52D6F580)
INSERT INTO @table VALUES (104, 101, 'Folder2', 0x52DA)

select * from @table

對於任何給定的PrimaryID-我想按順序生成所有標題的串聯列表

所需的輸入/輸出：

@input = 103
@output = \Root\Folder\Subfolder\Document

@input = 102
@output = \Root\Folder\Subfolder

@input = 104
@output = \Root\Folder\Folder2

我設法編寫了一個具有父子關系的遞歸CTE，並生成了標題列表，但是順序相反……例如，'\\ Document \\ SubFolder \\ Folder \\ Root'，我想反過來。

提前致謝

JW

Answer 1

看看下面想要的代碼

DECLARE @Input  NUMERIC = 104

DECLARE @Retstr VARCHAR(500) = ''

WHILE @Input > 0
BEGIN
    DECLARE @GetValue VARCHAR(500) =''
    DECLARE @ParentID NUMERIC = 0
    SELECT @GetValue = ISNULL(Title,''),@ParentID = ISNULL(ParentID,0) FROM #table WHERE PrimaryID = @Input
    IF(@GetValue != '')
    BEGIN
    IF(@Retstr!= '')
        BEGIN
            SET @Retstr =  @GetValue  + '\' + @Retstr 
        END
        ELSE
        BEGIN
            SET @Retstr =   @GetValue  
        END
    END
    SET @Input = @ParentID
END
IF(@Retstr!='')
BEGIN
    SET @Retstr = '\' + @Retstr
END
PRINT @Retstr