UPDATE Statement

Description

Creates an update query that changes values in fields in a specified table based on specified criteria.

Syntax

UPDATE table
SET newvalue
WHERE criteria;

The UPDATE statement has these parts.

Part	Description

table	The name of the table whose data you want to modify.
newvalue	An expression that determines the value to be inserted into a particular field in the updated records.
criteria	An expression that determines which records will be updated. Only records that satisfy the expression are updated.

Remarks

UPDATE is especially useful when you want to change many records or when the records that you want to change are in multiple tables.

You can change several fields at the same time. The following example increases the Order Amount values by 10 percent and the Freight values by 3 percent for shippers in the United Kingdom:

UPDATE Orders
SET OrderAmount = OrderAmount * 1.1,
Freight = Freight * 1.03
WHERE ShipCountry = 'UK';

UPDATE doesn't generate a result set. If you want to know which records will be changed, first examine the results of a select query that uses the same criteria, and then run the update query.

Specifics (Microsoft Access)

Since the UPDATE statement doesn't generate a result set, there is no query datasheet for Microsoft Access to display a when you use this statement.

If you want to confirm each change, you can use the Replace command on the Edit menu of the form or datasheet rather than an update query.

Example

This example changes values in the ReportsTo field to 5 for all employee records that currently have ReportsTo values of 2.

UPDATE Employees SET ReportsTo = 5 WHERE ReportsTo = 2;

This example increases the UnitPrice for all nondiscontinued products from supplier 8 by 10 percent.

UPDATE Products SET UnitPrice = UnitPrice * 1.1 
WHERE SupplierID = 8 AND Discontinued = No;

This example reduces the UnitPrice for all nondiscontinued products supplied by Tokyo Traders by 5 percent. The Products and Suppliers tables have a many-to-one relationship.

UPDATE Suppliers INNER JOIN Products ON Suppliers.SupplierID = Products.SupplierID SET UnitPrice = UnitPrice * .95 
WHERE CompanyName = 'Tokyo Traders' AND Discontinued = No;