Question

我意识到这一点：

IF EXISTS (SELECT * FROM table WHERE pk = @pk)
BEGIN
   --Update
END
ELSE
BEGIN 
   --INSERT
END

但这适用于一行。我们假设我有一个表min_max M和一个临时表__MinMaxImport T。我希望从T到M INSERT，但在{M}中已存在UPDATE / branch_no对时product。

INSERT：

INSERT INTO min_max
    (user_no, branch_no, product, min_stock, max_stock)
SELECT
    @user_no, _branch_no, _product, _min_stock, _max_stock
FROM 
    traxs_temp..__MinMaxImport 
WHERE 
    session_id = @session_id

更新：

UPDATE min_max SET
    date_time = GETDATE(),
    user_no = @user_no,
    min_stock = _min_stock,
    max_stock = _max_stock
FROM
    min_max M
    INNER JOIN traxs_temp..__MinMaxImport T ON T._product = M.product 
AND T._branch_no = M.branch_no
WHERE 
    session_id = @session_id

这样做的最佳解决方案是什么？我读到MERGE，但我不确定如何使用它。

Answer 1

MERGE应该能够做到。

MERGE INTO min_max
USING
(
    SELECT
        @user_no AS _user_no, _branch_no, _product, _min_stock, _max_stock
    FROM 
        traxs_temp..__MinMaxImport 
    WHERE 
        session_id = @session_id    
) AS Src
ON
    (min_max.branch_no = Src._branch_no) AND
    (min_max.product = Src._product)
WHEN MATCHED THEN 
UPDATE SET 
    date_time = GETDATE(),
    user_no = Src._user_no,
    min_stock = Src._min_stock,
    max_stock = Src._max_stock
WHEN NOT MATCHED BY TARGET THEN 
INSERT 
    (user_no, branch_no, product, min_stock, max_stock)
VALUES
    (Src._user_no,
    Src._branch_no,
    Src._product,
    Src._min_stock,
    Src._max_stock)
;

在一个范围上Upsert

1 个答案: