SQL - Klona en post och dess avkomlingar

Som Martin föreslog måste du aktivera IDENTITY_INSERT så att du kan driva dina egna identitetsvärden. Du kan också behöva skaffa ett tabelllås för att säkerställa att Max(Id) returnerar rätt värde.

If object_id('tempdb..#TestData') is not null
    Drop Table #TestData
GO
Create Table #TestData
    (
    Id int not null identity(1,1) Primary Key
    , ParentId int not null
    , Name varchar(50) not null
    )
GO
Set Identity_Insert #TestData On
GO  
Insert #TestData( Id, ParentId, Name )
Values( 1,0,'Food' )
    , ( 2,1,'Taste' )
    , ( 3,1,'Price' )
    , ( 4,2,'Taste Requirement' );


With Data As
    (
    Select Cast(MaxId.Id + 1 As int) As Id
        , T.ParentId
        , 'Copy Of ' + T.name As Name
        , T.Id As OldId
        , 0 As OldParentId
    From #TestData As T
        Cross Join( Select Max( id ) As Id From #TestData ) As MaxId
    Where T.Name = 'Food'
    Union All
    Select Cast(Parent.id + Row_Number() Over( Order By Child.Id ) + 1 As int)
        , Parent.Id
        , 'Copy of ' + Child.Name
        , Child.Id
        , Child.ParentId
    From Data As Parent
        Join #TestData As Child
            On Child.ParentId = Parent.OldId
    )
Insert #TestData( Id, ParentId, Name )
Select Id, ParentId, Name
From Data
GO
Set Identity_Insert #TestData Off
GO  

Resultat

id | parentid | name
-- | -------- | -----------------
1  | 0        | Food
2  | 1        | Taste
3  | 1        | Price
4  | 2        | Taste Requirement
5  | 0        | Copy Of Food
7  | 5        | Copy of Taste
8  | 5        | Copy of Price
9  | 7        | Copy of Taste Requirement