SQL 服务器中层次结构的递归克隆

Recursive clone of hierarchy in SQL Server

我在 table 中有一个层次结构:

Configuration 
(
    ConfigurationId int identity primary key,
    Name nvarchar(100),
    Value nvarchar(100),
    ParentId` int foreign key referencing ConfigurationId
)

我的任务是克隆一个父级及其所有子级,子级保持结构。请记住,ConfigurationId 是同一性,它需要保持同一性,不一定从 1 开始。我使用与用于插入/更新的过程相同的过程,仅使用 IsClone 参数。

程序如下所示:

ALTER PROCEDURE [dbo].[Configuration_Save]
    @ConfigurationId INT,
    @Name NVARCHAR(500),
    @Value NVARCHAR(500),
    @ParentId INT,
    @IsClone BIT
AS
BEGIN
    IF @IsClone = 0
    BEGIN
        IF (@ConfigurationId = 0)
        BEGIN
            INSERT INTO [Configuration]([Name], [Value], [ParentId])
            VALUES (@Name, @Value, @ParentId)
         END
         ELSE
         BEGIN
            UPDATE [Configuration] 
            SET [Name] = @Name, 
                [Value] = @Value, 
                ParentId = @ParentId
            WHERE ConfigurationId = @ConfigurationId
        END
    END
    ELSE -- IF IsClone = 1
    BEGIN
        DECLARE @SourceConfigid INT
        SET @SourceConfigid = @ConfigurationId

        DECLARE @ClonedConfigId INT

        INSERT INTO [Configuration] ([Name], [Value], ParentId)
        VALUES (@Name, @Value, NULL)

        SET @ClonedConfigId = SCOPE_IDENTITY()

       -- solution goes here

    END

    SELECT @ConfigurationId
END

当前数据如下所示:

  ConfigurationId    Name          Value   ParentId
  -------------------------------------------------------
    1                prod          NULL      NULL
    2                Security      NULL        1
    3                SecurityKey   NULL        2
    4                Issuer        NULL        2
    5                Audience      NULL        2
    6                SyncServer    NULL        1
    7                Address       NULL        6
    8                SmtpClient    NULL        1
    9                Host          NULL        8
    10               Port          NULL        8
    11               EnableSsl     NULL        8
    12               Username      NULL        8
    13               Password      NULL        8
    14               FromEmail     NULL        8
    15               Proxy         NULL        1
    16               UseProxy      NULL       15
    17               ProxyAddress  NULL       15
    18               AddressList   NULL       15
    19               Report        NULL        1
    20               ApiUrl        NULL       19

我希望能够通过插入一个名为 I通过执行存储过程输入并将行复制到当前行,唯一的区别是 ConfigurationId 是标识,ParentId 应根据新的 ConfigurationId 进行更改,同时保持层次结构。

所需数据如下所示:

   ConfigurationId   Name          Value   ParentId
   ------------------------------------------------
    1                prod          NULL      NULL
    2                Security      NULL         1
    3                SecurityKey   NULL         2
    4                Issuer        NULL         2
    5                Audience      NULL         2
    6                SyncServer    NULL         1
    7                Address       NULL         6
    8                SmtpClient    NULL         1
    9                Host          NULL         8
    10               Port          NULL         8
    11               EnableSsl     NULL         8
    12               Username      NULL         8
    13               Password      NULL         8
    14               FromEmail     NULL         8
    15               Proxy         NULL         1
    16               UseProxy      NULL        15
    17               ProxyAddress  NULL        15
    18               AddressList   NULL        15
    19               Report        NULL         1
    20               ApiUrl        NULL        19
    21               prod2         NULL      NULL
    22               Security      NULL        21
    23               SecurityKey   NULL        22
    24               Issuer        NULL        22
    25               Audience      NULL        22
    26               SyncServer    NULL        21
    27               Address       NULL        26
    28               SmtpClient    NULL        21
    29               Host          NULL        28
    30               Port          NULL        28
    31               EnableSsl     NULL        28
    32               Username      NULL        28
    33               Password      NULL        28
    34               FromEmail     NULL        28
    35               Proxy         NULL        21
    36               UseProxy      NULL        35
    37               ProxyAddress  NULL        35
    38               AddressList   NULL        35
    39               Report        NULL        21
    40               ApiUrl        NULL        39

与嵌套游标、合并和调用过程/函数相比,我更喜欢 CTE 解决方案。我尝试了几个以相似名称列出的解决方案,但没有成功。

编辑 1: 示例数据的格式

编辑 2: 只能克隆根节点,这意味着只有 ParentId = NULL 的条目是克隆选项。

如有任何帮助,我们将不胜感激。

有许多可用的答案显示如何使用递归 CTE 附加一些路径信息。这是一个需要根据您的排序偏好进行调整的示例:

;with cteHierarchy  AS (
SELECT ConfigurationId, NAme, Value, ParentId,
    CAST(ConfigurationID AS varchar(255)) As HierarchyPath
FROM #Configuration WHERE ParentId IS NULL
UNION ALL
SELECT C.ConfigurationId, C.NAme, C.Value, C.ParentId,
    --I prefer CONCAT(), but not sure of your SQL version
    CAST(P.HierarchyPath + '.' + CAST(C.ConfigurationID AS varchar(255)) as varchar(255)) As HierarchyPath
FROM #Configuration C
JOIN cteHierarchy P ON C.ParentId = P.ConfigurationId
)

SELECT * FROM cteHierarchy Order By HierarchyPath

以下代码使用 CTE 和 update 来制作指定层次结构的副本。 CTE 递归地从根遍历到叶子,并提供一个 insert 来添加 "copies" 行。 insert 上的 output 子句生成 table 个修正对,其中包含每个新行的旧值和新值 ConfigurationId。由于 output 子句只能访问插入的列值,我们 "borrow" 一个列 (Value) 来存储旧的 ConfigurationId 值。然后使用 update 设置两列:更新 ParentId 值以引用复制的行,并从原始行恢复 Value 值。

注意,繁忙的工作应该包裹在事务中。它用于确保复制完成或没有落后者被遗忘,它需要防止其他会话看到不完整的结果或更改完成复制所需的旧 Value 数据。

-- Sample data.
declare @Configuration as Table (
  ConfigurationId Int Identity,
  Name NVarChar(100),
  Value NVarChar(100),
  ParentId Int );

insert into @Configuration ( Name, Value, ParentId ) values
  ( 'prod', NULL, NULL ),
  ( 'Security', NULL, 1 ),
  ( 'SecurityKey', NULL, 2 ),
  ( 'Issuer', NULL, 2 ),
  ( 'Audience', NULL, 2 ),
  ( 'SyncServer', NULL, 1 ),
  ( 'Address', NULL, 6 );
    --8                SmtpClient    NULL        1
    --9                Host          NULL        8
    --10               Port          NULL        8
    --11               EnableSsl     NULL        8
    --12               Username      NULL        8
    --13               Password      NULL        8
    --14               FromEmail     NULL        8
    --15               Proxy         NULL        1
    --16               UseProxy      NULL       15
    --17               ProxyAddress  NULL       15
    --18               AddressList   NULL       15
    --19               Report        NULL        1
    --20               ApiUrl        NULL       19

-- Raw sample data.
select * from @Configuration;

-- Tree sample data.
with Configuration as (
  select ConfigurationId, Name, Value, ParentId,
    Cast( Right( '0000' + Cast( ConfigurationId as NVarChar(4) ), 4 ) as NVarChar(1024) ) as Path
    from @Configuration
    where ParentId is NULL
  union all
  select CC.ConfigurationId, CC.Name, CC.Value, CC.ParentId,
    Cast( Path + N'→' + Right( '0000' + Cast( CC.ConfigurationId as NVarChar(4) ), 4 ) as NVarChar(1024) )
    from Configuration as PC inner join
      @Configuration as CC on CC.ParentId = PC.ConfigurationId )
  select *
    from Configuration
    order by Path;

-- Copy the tree.
declare @RootConfigurationId as Int = 1;
declare @Fixups as Table ( OriginalConfigurationId NVarChar(10), CopyConfigurationId Int );

-- NB: The isolation level needs to guarantee that the   Value   in the
--   source rows doesn't get changed whilst we fiddle about, nor do we want anyone else peeking.
begin transaction;

-- Copy the tree and save the new identity values.
--   We cheat and tuck the old   ConfigurationId   into the   Value   column so that the
--   output   clause can save the original and copy   ConfigurationId   values for fixup.
with Configuration as (
select ConfigurationId, Name, Value, ParentId
  from @Configuration
  where ConfigurationId = @RootConfigurationId
union all
select CC.ConfigurationId, CC.Name, CC.Value, CC.ParentId
  from Configuration as PC inner join
    @Configuration as CC on CC.ParentId = PC.ConfigurationId )
insert into @Configuration ( Name, Value, ParentId )
  output inserted.Value, inserted.ConfigurationId into @Fixups
  select Name, Cast( ConfigurationId as NVarChar(10) ), ParentId
    from Configuration as C;

-- Display the intermediate results.
select * from @Fixups;
select * from @Configuration;

-- Fix up the parentage and replace the original values.
update C
  set C.ParentId = F2.CopyConfigurationId, Value = CV.Value
  from @Configuration as C inner join -- New rows to be fixed.
    @Fixups as F on F.CopyConfigurationId = C.ConfigurationId inner join -- New row identity values.
    @Configuration as CV on CV.ConfigurationId = F.OriginalConfigurationId left outer join -- Original   Value .
    @Fixups as F2 on F2.OriginalConfigurationId = C.ParentId; -- Lookup the new   ParentId , if any, for each row.

-- Raw sample data.
select * from @Configuration;

-- Tree sample data.
with Configuration as (
  select ConfigurationId, Name, Value, ParentId,
    Cast( Right( '0000' + Cast( ConfigurationId as NVarChar(4) ), 4 ) as NVarChar(1024) ) as Path
    from @Configuration
    where ParentId is NULL
  union all
  select CC.ConfigurationId, CC.Name, CC.Value, CC.ParentId,
    Cast( Path + N'→' + Right( '0000' + Cast( CC.ConfigurationId as NVarChar(4) ), 4 ) as NVarChar(1024) )
    from Configuration as PC inner join
      @Configuration as CC on CC.ParentId = PC.ConfigurationId )
  select *
    from Configuration
    order by Path;

commit transaction;