An Update query is a type of action query that makes changes to several records at the same time. For example, you could create an Update query to raise prices on all the products in a table by 10%.
Just like other action queries, you create an Update query by first creating a Select query and then converting the Select query to an Update query.
Access converts the Select query to an Update query. Notice an Update To row appears in the design grid. Now you should specify the fields you want to update.
The next step can be a little bit tricky—you need to tell Access which fields to update and how to update them. For example, if you wanted to raise the price of the Normal Price field by 10 percent you would write an expression—like [Normal Price]+([Normal Price]*.1)—in the field's Update To row to make this happen.