在SQL中將行從一個復制到另一個表

Question

我有兩個數據庫-db1和db2，如下所示：

db1..Model

ModelId ModelName
0       BMW

db1..Category

CategoryId  CategoryName
0           Undercarriage
1           Engine

db1..ItemList

ModelId CategoryId      DataId  Name
0       0               1       cap
0       0               2       cushion
0       0               3       spacer
0       1               1       cushion

然后，我將模型和類別從db1復制到db2：

db2..Model

Id  ModelName
1   BMW

db2..Category

Id  CategoryName
1   Undercarriage
2   Engine

我如何將記錄寫到db2..Item中，以便行應像這樣：

Id  ModelId     CategoryId  DataId  Name
1   1           1           1       cap
2   1           1           2       cushion
3   1           1           3       spacer
4   1           2           1       cushion 

Answer 1

假設db1和db2在同一台服務器上，則應如下所示：

INSERT INTO db2.dbo.Item (ModelId, CategoryId, DataId, Name)
SELECT
    (
        SELECT Model.Id
        FROM db2.dbo.Model
        WHERE db2.dbo.Model.ModelName = (
            SELECT Model.ModelName
            FROM db1.dbo.Model
            WHERE Model.ModelId = ItemList.ModelId
        )
    )
    (
        SELECT Category.Id
        FROM db2.dbo.Category
        WHERE db2.dbo.Category.CategoryName = (
            SELECT Category.CategoryName
            FROM db1.dbo.Category
            WHERE Category.CategoryId = ItemList.CategoryId
        )
    )
    DataId,
    Name
FROM db1.dbo.ItemList