Question

考虑以下设计：

Company TABLE (
    CompanyId int NOT NULL IDENTITY PRIMARY KEY,
    CompanyName nvarchar(max))
Product TABLE (
    ProductId int NOT NULL IDENTITY PRIMARY KEY,
    CompanyId int NOT NULL,
    ProductName nvarchar(max))
ProductPart TABLE (
    ProductPartId int NOT NULL IDENTITY PRIMARY KEY,
    ProductId int NOT NULL,
    ProductPartName)

我需要复制一家公司（包含CompanyId == @companyId）数据，因此它将包含完全相同的数据。

第一步显而易见：

INSERT INTO Company(CompanyName)
SELECT @newCompanyName
FROM Company
WHERE CompanyId = @companyId

DECLARE @newCompanyId = SCOPE_IDENTITY()

如果没有ProductPart表，复制Product数据也是微不足道的：

INSERT INTO Product (ProductName)
SELECT ProductName
FROM Product
WHERE CompanyId = @companyId

但为了正确复制ProductPart数据，我需要在新旧公司之间提供产品映射数据。

我尝试使用OUTPUT子句但不幸的是它不支持我的场景：

DECLARE @productRemap TABLE (OldProductId int NOT NULL, NewProductId int NOT NULL PRIMARY KEY)
INSERT INTO Product (ProductName)
    OUTPUT ProductId, inserted.ProductId
        INTO @productRemap
SELECT ProductName
FROM Product
WHERE CompanyId = @companyId
-- Invalid column name 'ProductId'.

有没有办法在不涉及游标的情况下正确复制数据？

Answer 1

感谢Mikael，我发现我实际上可以使用MERGE代替INSERT：

DECLARE @productRemap
    TABLE (OldProductId int NOT NULL, NewProductId int NOT NULL)

-- Duplicate products
MERGE INTO Product AS t
USING (
    SELECT *
    FROM Product
    WHERE CompanyId = @companyId) AS s
ON (0 = 1)
WHEN NOT MATCHED THEN
    INSERT (ProductName, CompanyId)
    VALUES (ProductName, @newCompanyId)
    OUTPUT s.ProductId, inserted.ProductId
        INTO @productRemap;

然后我可以使用ProductPart：

的映射插入@productRemap

MERGE INTO ProductPart AS t
USING (
    SELECT * FROM ProductPart
        INNER JOIN @productRemap ON ProductId = OldProductId) AS s
ON (0 = 1)
WHEN NOT MATCHED THEN
    INSERT (ProductId, ProductPartName)
    VALUES (NewProductId, ProductPartName)

Answer 2

我知道您希望严格使用TSQL执行此操作，但是，从表格体验来看，我发现将OldProductId字段添加到Product表并从中映射产品部件最简单：< / p>

INSERT INTO Product (ProductName, OldProductId)
SELECT ProductName, ProductId
FROM Product
WHERE CompanyId = @companyId

带有标识列的重复记录

2 个答案: