Question

我在SQL Server中遇到一个问题，一次复制多个相关表。

我有两张桌子。一个是StageDetails，另一个是StageDetailsItem。

StageDetails表包含三行，StageDetailsItem表包含十五行。 StageDetails中的每一行在StageDetailsItem中都有五行。

StateDetails和StageDetailsItems之间存在主要详细信息关系。

我想一次性复制三条StageDetails条记录和十五条StageDetailsItem条记录进入相同的表格，我想更改StageDetailID的{{1}} 何时插入StageDetailsItem。

我不想使用明确的循环，例如StageDetailsItem，CURSOR等。

以下是WHILE和StageDetails的DDL脚本。

StageDetailsItem

我可以轻松地从一个表中复制记录，如下所示：

CREATE TABLE [dbo].[StageDetail](
    [StageDetailID] [int] IDENTITY(1,1) NOT NULL,
    [StageNUmber] [nvarchar](50) NULL,
    [TypeOfStage] [nvarchar](500) NULL,
    [Distance] [nvarchar](500) NULL,
CONSTRAINT [PK_StageDetail] PRIMARY KEY CLUSTERED 
(
    [StageDetailID] ASC
) WITH (
    PAD_INDEX = OFF, 
    STATISTICS_NORECOMPUTE = OFF, 
    IGNORE_DUP_KEY = OFF, 
    ALLOW_ROW_LOCKS = ON, 
    ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

CREATE TABLE [dbo].[StageDetailItem](
    [StageDetailItemID] [int] IDENTITY(1,1) NOT NULL,
    [StageDetailID] [int] NULL,
    [Road] [nvarchar](500) NULL,
    [CostPer] [nvarchar](500) NULL,
CONSTRAINT [PK_StageDetailItem] PRIMARY KEY CLUSTERED 
(
    [StageDetailItemID] ASC
) WITH (
    PAD_INDEX = OFF, 
    STATISTICS_NORECOMPUTE = OFF, 
    IGNORE_DUP_KEY = OFF, 
    ALLOW_ROW_LOCKS = ON, 
    ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[StageDetailItem] WITH CHECK 
ADD CONSTRAINT [FK_StageDetailItem_StageDetail] FOREIGN KEY([StageDetailID])
REFERENCES [dbo].[StageDetail] ([StageDetailID])
GO

ALTER TABLE [dbo].[StageDetailItem] 
CHECK CONSTRAINT [FK_StageDetailItem_StageDetail]
GO

Answer 1

此处描述的解决方案可在多用户环境中正常运行。

我将MERGE与OUTPUT条款一起使用。

MERGE可以INSERT，UPDATE和DELETE行。在这种情况下，我们只需要INSERT。

1=0始终为false，因此始终会执行NOT MATCHED BY TARGET部分。一般来说，可能还有其他分支，请参阅docs。 WHEN MATCHED通常用于UPDATE; WHEN NOT MATCHED BY SOURCE通常用于DELETE，但我们在这里不需要它们。

这种令人费解的MERGE形式相当于简单INSERT，但与简单INSERT不同，它的OUTPUT子句允许引用我们需要的列。它允许从源表和目标表中检索列，从而节省映射旧现有ID与IDENTITY生成的新ID之间。

示例数据

INSERT INTO [dbo].[StageDetail]
    ([StageNUmber]
    ,[TypeOfStage]
    ,[Distance])
VALUES
    ('sn01','t1','D1'),
    ('sn02','t2','D2'),
    ('sn03','t3','D3');

INSERT INTO [dbo].[StageDetailItem]
    ([StageDetailID]
    ,[Road]
    ,[CostPer])
VALUES
    (1,'r1_1','C11'),
    (1,'r1_2','C12'),
    (1,'r1_3','C13'),
    (1,'r1_4','C14'),
    (1,'r1_5','C15'),

    (2,'r2_1','C16'),
    (2,'r2_2','C17'),
    (2,'r2_3','C18'),
    (2,'r2_4','C19'),
    (2,'r2_5','C20'),

    (3,'r3_1','C21'),
    (3,'r3_2','C22'),
    (3,'r3_3','C23'),
    (3,'r3_4','C24'),
    (3,'r3_5','C25');

<强>查询

声明一个表变量（或临时表）来保存旧ID和新ID之间的映射。

DECLARE @T TABLE(OldStageDetailID int, NewStageDetailID int);

首先从StageDetail表格中复制一行，记住表格变量中ID的映射。

MERGE INTO [dbo].[StageDetail]
USING
(
    SELECT [StageDetailID],[StageNUmber],[TypeOfStage],[Distance]
    FROM [dbo].[StageDetail]
) AS Src
ON 1 = 0
WHEN NOT MATCHED BY TARGET THEN
INSERT ([StageNUmber],[TypeOfStage],[Distance])
VALUES
    (Src.[StageNUmber]
    ,Src.[TypeOfStage]
    ,Src.[Distance])
OUTPUT 
    Src.[StageDetailID] AS OldStageDetailID
    ,inserted.[StageDetailID] AS NewStageDetailID
INTO @T(OldStageDetailID, NewStageDetailID)
;

然后使用新的StageDetailItem从StageDetailIDs复制行。

INSERT INTO [dbo].[StageDetailItem]
    ([StageDetailID]
    ,[Road]
    ,[CostPer])
SELECT
    T.[NewStageDetailID]
    ,[dbo].[StageDetailItem].[Road]
    ,[dbo].[StageDetailItem].[CostPer]
FROM
    [dbo].[StageDetailItem]
    INNER JOIN @T AS T ON T.OldStageDetailID = [dbo].[StageDetailItem].StageDetailID
;

<强>结果

SELECT * FROM [dbo].[StageDetail]

+---------------+-------------+-------------+----------+
| StageDetailID | StageNUmber | TypeOfStage | Distance |
+---------------+-------------+-------------+----------+
|             1 | sn01        | t1          | D1       |
|             2 | sn02        | t2          | D2       |
|             3 | sn03        | t3          | D3       |
|             4 | sn01        | t1          | D1       |
|             5 | sn02        | t2          | D2       |
|             6 | sn03        | t3          | D3       |
+---------------+-------------+-------------+----------+

SELECT * FROM [dbo].[StageDetailItem]

+-------------------+---------------+------+---------+
| StageDetailItemID | StageDetailID | Road | CostPer |
+-------------------+---------------+------+---------+
|                 1 |             1 | r1_1 | C11     |
|                 2 |             1 | r1_2 | C12     |
|                 3 |             1 | r1_3 | C13     |
|                 4 |             1 | r1_4 | C14     |
|                 5 |             1 | r1_5 | C15     |
|                 6 |             2 | r2_1 | C16     |
|                 7 |             2 | r2_2 | C17     |
|                 8 |             2 | r2_3 | C18     |
|                 9 |             2 | r2_4 | C19     |
|                10 |             2 | r2_5 | C20     |
|                11 |             3 | r3_1 | C21     |
|                12 |             3 | r3_2 | C22     |
|                13 |             3 | r3_3 | C23     |
|                14 |             3 | r3_4 | C24     |
|                15 |             3 | r3_5 | C25     |
|                16 |             4 | r1_1 | C11     |
|                17 |             4 | r1_2 | C12     |
|                18 |             4 | r1_3 | C13     |
|                19 |             4 | r1_4 | C14     |
|                20 |             4 | r1_5 | C15     |
|                21 |             5 | r2_1 | C16     |
|                22 |             5 | r2_2 | C17     |
|                23 |             5 | r2_3 | C18     |
|                24 |             5 | r2_4 | C19     |
|                25 |             5 | r2_5 | C20     |
|                26 |             6 | r3_1 | C21     |
|                27 |             6 | r3_2 | C22     |
|                28 |             6 | r3_3 | C23     |
|                29 |             6 | r3_4 | C24     |
|                30 |             6 | r3_5 | C25     |
+-------------------+---------------+------+---------+

使用主 - 详细信息关系复制多个记录

1 个答案: