How to update table with only new or changed values?
Here is my query but it makes lots of doubles and I need insert new and (maybe) update changed values.
INSERT INTO [FRIIB].[dbo].[ArchiveAnalog]
开发者_如何学Go (Date, ID, Value)
SELECT Date, ID, Value
FROM [LinkedOne].[FRIIB].[dbo].[ArchiveAnalog]
My problem is I need to compare not single value , I need to compare whole node with 3 values to check if there is existing ones.
thank you.
Assuming SQL Server 2008 or above, use MERGE
e.g.
MERGE INTO [FRIIB].[dbo].[ArchiveAnalog]
USING (
SELECT [Date], ID, [Value]
FROM [LinkedOne].[FRIIB].[dbo].[ArchiveAnalog]
) AS source ([Date], ID, [Value])
ON [Date] = source.[Date]
AND ID = source.ID
AND [Value] = source.[Value]
WHEN NOT MATCHED THEN
INSERT ([Date], ID, [Value])
VALUES ([Date], ID, [Value]);
To insert the missing values, following would do
INSERT INTO [FRIIB].[dbo].[ArchiveAnalog] (Date, ID, Value)
SELECT laa.Date, laa.ID, laa.Value
FROM [LinkedOne].[FRIIB].[dbo].[ArchiveAnalog] laa
LEFT OUTER JOIN [FRIIB].[dbo].[ArchiveAnalog] aa ON aa.Date = laa.Date
AND aa.ID = laa.ID
AND aa.Value = laa.Value
WHERE aa.ID IS NULL
To update existing values you might want to look into the MERGE
statement
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