Question

Below is my table Schema:

CREATE TABLE [dbo].[Sample](
    [BoardId] [int] IDENTITY(1,1) NOT NULL,
    [UserCode] [nvarchar](20) NOT NULL,
    [Desc] [nvarchar](100) NOT NULL,
    [Version] [int] NOT NULL,
    [ParentId] [int] NULL,
    [CreatedOn] [datetime] NOT NULL,
    [ModifiedOn] [datetime] NOT NULL)

short description about the table, User can opt to save “Desc”[User info as per the user] as a seperate version each time. I would like to generate a version number for each subVersion being created. The parentId field holds the PK ID for which the subversion is being created.
For example, some records below.

boardID        UserCode     Desc       Version   ParentID  CreatedOn       ModifiedOn
1              12343jhgs    blah blah    1          0        ---            ---
2              12343jhgs    blah blah    1          1        ---            ---
3              12343jhgs    blah blah    2          1        ---            ---
4              73627ggjh    lol lol ol   1          0        ---            ---

Hope you are getting the idea, for each subversion created i would like to generate a Version number that increments.

Answer 1

An example based on your sample data. I have assumed that the version number of instances of boardId with the same ParentId is determined by order of insertion.

EDIT – re-reading your description and comments I realised that the parent and first child having version 1 was intentional:

DECLARE @Sample TABLE 
(
    [BoardId] [INT] NOT NULL,
    [UserCode] [NVARCHAR](20) NOT NULL,
    [Desc] [NVARCHAR](100) NOT NULL,
    [ParentId] [INT] NULL,
    [CreatedOn] [DATETIME] ,
    [ModifiedOn] [DATETIME]
)

INSERT @Sample
(boardID,UserCode,[Desc],ParentID)
VALUES
(1,'12343jhgs','blah blah',0),
(2,'12343jhgs','blah blah',1),
(3,'12343jhgs','blah blah',1),
(4,'73627ggjh','lol lol ol',0)


;WITH recCTE
AS
(
    SELECT  boardID,UserCode,[Desc],ParentID, BoardID AS TopParent, 0 as versionModifier
    FROM    @Sample
    WHERE   ParentId = 0

    UNION ALL

    SELECT  s.boardID,s.UserCode,s.[Desc],s.ParentID, r.TopParent, -1 as versionModifier
    FROM    @Sample AS s 
    JOIN    recCTE AS r 
    ON      r.BoardId = s.ParentId
)
SELECT  boardID,UserCode,[Desc],ParentID, BoardID, 
        ROW_NUMBER() OVER (PARTITION BY TopParent
                            ORDER BY    boardId
                          )   + versionModifier AS [Version]
FROM recCTE