ー
This example updates the values in the Bonus, CommissionPct, and SalesQuota columns for all rows in the SalesPerson table. 

USE AdventureWorks;
GO
UPDATE Sales.SalesPerson
SET Bonus = 6000, CommissionPct = .10, SalesQuota = NULL;
GO


ー
USE AdventureWorks ;
GO
UPDATE Production.Product
SET ListPrice = ListPrice * 2;
GO

ー
USE AdventureWorks;
GO
UPDATE Production.Product
SET Color = N'Metallic Red'
WHERE Name LIKE N'Road-250%' AND Color = N'Red';
GO

ーUpdate with information from another table
The following example modifies the SalesYTD column in the SalesPerson table to reflect the most recent sales recorded in the SalesOrderHeader table.


USE AdventureWorks;
GO
UPDATE Sales.SalesPerson
SET SalesYTD = SalesYTD + SubTotal
FROM Sales.SalesPerson AS sp
JOIN Sales.SalesOrderHeader AS so
    ON sp.SalesPersonID = so.SalesPersonID
    AND so.OrderDate = (SELECT MAX(OrderDate)
                        FROM Sales.SalesOrderHeader 
                        WHERE SalesPersonID = 
                              sp.SalesPersonID);
GO


ー
The previous example assumes that only one sale is recorded for a specified salesperson on a specific date and that updates are current. If more than one sale for a specified salesperson can be recorded on the same day, the example shown does not work correctly. The example runs without error, but each SalesYTD value is updated with only one sale, regardless of how many sales actually occurred on that day. This is because a single UPDATE statement never updates the same row two times.

In the situation in which more than one sale for a specified salesperson can occur on the same day, all the sales for each sales person must be aggregated together within the UPDATE statement, as shown in this example:


USE AdventureWorks;
GO
UPDATE Sales.SalesPerson
SET SalesYTD = SalesYTD + 
    (SELECT SUM(so.SubTotal) 
     FROM Sales.SalesOrderHeader AS so
     WHERE so.OrderDate = (SELECT MAX(OrderDate)
                           FROM Sales.SalesOrderHeader AS so2
                           WHERE so2.SalesPersonID = 
                                 so.SalesPersonID)
     AND Sales.SalesPerson.SalesPersonID = so.SalesPersonID
     GROUP BY so.SalesPersonID);
GO

ーUpdate with the TOP clause
USE AdventureWorks;
GO
UPDATE TOP (10) HumanResources.Employee
SET VacationHours = VacationHours * 1.25 ;
GO