Can Linq to SQL/Linq to Entities generate a MERGE

问题:

Looking for a combined INSERT/UPDATE/DELETE statement, MERGE is exactly what I need, but I can't seem to find if LINQ/SQL supports it (from http://www.sqlbook.com/SQL-Server/SQL-MERGE-35.aspx)

-- Merge order items into OrderItems table
MERGE INTO OrderItem As oi
USING @UpdatedItems ui
ON (oi.OrderID = ui.OrderID AND oi.ProductID = ui.ProductID)
WHEN MATCHED THEN
    UPDATE SET Quantity = ui.Quantity, UnitCost = ui.UnitCost
WHEN NOT MATCHED THEN
    INSERT (OrderID, ProductID, Quantity, UnitCost)
    VALUES (@OrderID, ui.ProductID, ui.Quantity, ui.UnitCost)
WHEN SOURCE NOT MATCHED THEN
    DELETE;

回答1:

Current version of LINQ to SQL does not generate a MERGE statement. You must create a custom Upsert method in code to do an Upsert.