tsql merge example
MERGE esqlProductTarget T
USING esqlProductSource S
ON (S.ProductID = T.ProductID)
WHEN MATCHED
THEN UPDATE
SET T.Name = S.Name,
T.ProductNumber = S.ProductNumber,
T.Color = S.Color
WHEN NOT MATCHED BY TARGET
THEN INSERT (ProductID, Name, ProductNumber, Color)
VALUES (S.ProductID, S.Name, S.ProductNumber, S.Color)
WHEN NOT MATCHED BY SOURCE
THEN DELETE;