复制主从数据的存储过程

Question

我是新的存储过程，并试图编写一个过程来将用户（通过 user_id）主详细数据复制到新的用户数据中。这是我的表结构。我会将目标 user_id 和目标 user_id 传递给存储过程。你能告诉我如何实现这个功能吗？感谢您的帮助。

TABLE A
----------------
a_id       int(Primary Key)  
desc       varchar(50)
user_id    int

TABLE B
-----------------
b_id       int(Primary Key)
a_id       int(Foreign Key)
detail     varchar(100)

CREATE PROCEDURE [duplicate_user_data] 
    @old_user_id int,
    @new_user_id int
AS
BEGIN
    INSERT INTO TABLEA
           ([desc]
           ,[user_id]
           )
    select desc, user_id from TABLEA where user_id = @old_user_id
END

Answer 1

您可以使用自联接来匹配新旧父 ID。

CREATE PROCEDURE [duplicate_user_data] 
    @old_user_id int,
    @new_user_id int
AS
    INSERT INTO TableA ([desc], [user_id])
    SELECT [desc], @new_user_id
    FROM TableA
    WHERE [user_id] = @old_user_id

    INSERT INTO TableB ([a_id], [detail])
    SELECT NewTableA.[a_id], TableB.[detail]
    FROM TableA AS NewTableA
    CROSS JOIN TableA AS OldTableA
    JOIN TableB ON TableB.[a_id] = OldTableA.[a_id]
    WHERE NewTableA.[user_id] = @new_user_id
    AND OldTableA.[user_id] = @old_user_id

Answer 2

如果我对您的理解正确，您想为新用户插入一条新记录，但从另一个用户那里复制详细信息。如果是这样，那么你可以这样做：

CREATE PROCEDURE [duplicate_user_data] 
    @old_user_id int,
    @new_user_id int
AS
BEGIN
    declare @old_a_id int

    -- get the old a_id first
    SELECT @old_a_id = a_id
    FROM TableA
    WHERE [user_id] = @old_user_id

    -- insert the new record into TableA
    INSERT INTO TABLEA
    (
        [desc]
        ,[user_id]
    )
    select [desc]
        , @new_user_id 
    from TABLEA 
    where [user_id] = @old_user_id

    -- insert new record into tableB using the @old_a_id 
    INSERT INTO TableB
    (
        a_id
        , detail
    )
    SELECT @old_a_id
        , detail
    FROM TableB
    WHERE a_id = @old_a_id
END

然后，这会将您的 new_user_id 插入到 TableA 中，但会从您的 old_user_id 中获得 [desc]