Sql-server – Parent-Child Tree Hierarchical ORDER

hierarchyorder-bysql serversql-server-2008-r2

I have to following data in SQL Server 2008 R2. SQLFiddle

Schema:

CREATE TABLE [dbo].[ICFilters](
   [ICFilterID] [int] IDENTITY(1,1) NOT NULL,
   [ParentID] [int] NOT NULL DEFAULT 0,
   [FilterDesc] [varchar](50) NOT NULL,
   [Active] [tinyint] NOT NULL DEFAULT 1,
 CONSTRAINT [PK_ICFilters] PRIMARY KEY CLUSTERED 
 ( [ICFilterID] ASC ) WITH 
    PAD_INDEX  = OFF,
    STATISTICS_NORECOMPUTE = OFF,
    IGNORE_DUP_KEY = OFF,
    ALLOW_ROW_LOCKS  = ON,
    ALLOW_PAGE_LOCKS  = ON
 ) ON [PRIMARY]
) ON [PRIMARY]

INSERT INTO [dbo].[ICFilters] (ParentID,FilterDesc,Active)
Values 
(0,'Product Type',1),
(1,'ProdSubType_1',1),
(1,'ProdSubType_2',1),
(1,'ProdSubType_3',1),
(1,'ProdSubType_4',1),
(2,'PST_1.1',1),
(2,'PST_1.2',1),
(2,'PST_1.3',1),
(2,'PST_1.4',1),
(2,'PST_1.5',1),
(2,'PST_1.6',1),
(2,'PST_1.7',0),
(3,'PST_2.1',1),
(3,'PST_2.2',0),
(3,'PST_2.3',1),
(3,'PST_2.4',1),
(14,'PST_2.2.1',1),
(14,'PST_2.2.2',1),
(14,'PST_2.2.3',1),
(3,'PST_2.8',1)

Table:

| ICFILTERID | PARENTID |    FILTERDESC | ACTIVE |
--------------------------------------------------
|          1 |        0 |  Product Type |      1 |
|          2 |        1 | ProdSubType_1 |      1 |
|          3 |        1 | ProdSubType_2 |      1 |
|          4 |        1 | ProdSubType_3 |      1 |
|          5 |        1 | ProdSubType_4 |      1 |
|          6 |        2 |       PST_1.1 |      1 |
|          7 |        2 |       PST_1.2 |      1 |
|          8 |        2 |       PST_1.3 |      1 |
|          9 |        2 |       PST_1.4 |      1 |
|         10 |        2 |       PST_1.5 |      1 |
|         11 |        2 |       PST_1.6 |      1 |
|         12 |        2 |       PST_1.7 |      0 |
|         13 |        3 |       PST_2.1 |      1 |
|         14 |        3 |       PST_2.2 |      0 |
|         15 |        3 |       PST_2.3 |      1 |
|         16 |        3 |       PST_2.4 |      1 |
|         17 |       14 |     PST_2.2.1 |      1 |
|         18 |       14 |     PST_2.2.2 |      1 |
|         19 |       14 |     PST_2.2.3 |      1 |
|         20 |        3 |       PST_2.8 |      1 |

Every row has the ID of its parent and the root's parentid = 0. The FilterDescs are just sample descriptions so I can't try to parse those for ordering.

The Question

Is it possible to select all the rows in a tree-like manner? If so, how?
When I say 'tree-like', I mean recursively select the parent followed by all of its children, then all the children of each one of those and so on. A Depth first tree traversal.

My Friends and I have tried but we have fallen short of working solutions but will keep trying. I am fairly new to sql so maybe this can be done easily and i'm just making things harder than necessary.

Example(desired) output:

| ICFILTERID | PARENTID |    FILTERDESC | ACTIVE |
--------------------------------------------------
|          1 |        0 |  Product Type |      1 |
|          2 |        1 | ProdSubType_1 |      1 |
|          6 |        2 |       PST_1.1 |      1 |
|          7 |        2 |       PST_1.2 |      1 |
|          8 |        2 |       PST_1.3 |      1 |
|          9 |        2 |       PST_1.4 |      1 |
|         10 |        2 |       PST_1.5 |      1 |
|         11 |        2 |       PST_1.6 |      1 |
|         12 |        2 |       PST_1.7 |      0 |
|          3 |        1 | ProdSubType_2 |      1 |
|         13 |        3 |       PST_2.1 |      1 |
|         14 |        3 |       PST_2.2 |      0 |
|         17 |       14 |     PST_2.2.1 |      1 |
|         18 |       14 |     PST_2.2.2 |      1 |
|         19 |       14 |     PST_2.2.3 |      1 |
|         15 |        3 |       PST_2.3 |      1 |
|         16 |        3 |       PST_2.4 |      1 |
|         20 |        3 |       PST_2.8 |      1 |
|          4 |        1 | ProdSubType_3 |      1 |
|          5 |        1 | ProdSubType_4 |      1 |

Best Answer

OK, enough brain cells are dead.

SQL Fiddle

WITH cte AS
(
  SELECT 
    [ICFilterID], 
    [ParentID],
    [FilterDesc],
    [Active],
    CAST(0 AS varbinary(max)) AS Level
  FROM [dbo].[ICFilters]
  WHERE [ParentID] = 0
  UNION ALL
  SELECT 
    i.[ICFilterID], 
    i.[ParentID],
    i.[FilterDesc],
    i.[Active],  
    Level + CAST(i.[ICFilterID] AS varbinary(max)) AS Level
  FROM [dbo].[ICFilters] i
  INNER JOIN cte c
    ON c.[ICFilterID] = i.[ParentID]
)

SELECT 
  [ICFilterID], 
  [ParentID],
  [FilterDesc],
  [Active]
FROM cte
ORDER BY [Level];