Question

我是T-SQL命令MERGE的新手，所以我在SQL逻辑中找到了一个可以使用它的地方，想要测试它，但无法弄清楚我应该如何使用它：< / p>

IF (EXISTS (SELECT 1 FROM commissions_history WHERE request = @requestID))
    UPDATE commissions_history
    SET amount = @amount
    WHERE request = @requestID
ELSE
    INSERT INTO commissions_history (amount) VALUES @amount)

请建议正确使用。谢谢！

Answer 1

你看过帮忙了吗？这是一个简单的例子：

MERGE dbo.commissions_history AS target
USING (SELECT @amount, @requestID) AS source (amount, request)
ON (target.request = source.request)
WHEN MATCHED THEN
    UPDATE SET amount = source.amount
WHEN NOT MATCHED THEN
    INSERT (request, amount)
    VALUES (source.request, source.amount);

Answer 2

我希望它会起作用

MERGE commissions_history AS target
USING (SELECT request FROM  commissions_history WHERE request = @requestID) AS source (request)
ON (target.request = source.request)
WHEN MATCHED THEN 
    UPDATE SET amount = @amount
WHEN NOT MATCHED BY SOURCE    
    INSERT (request, amount)
    VALUES (@requestID,  @amount)

在这种情况下如何使用T-SQL MERGE？

2 个答案: