So far, you’ve been working with all the records of the tblContacts and tblProducts tables. Most often users want to work only with records conforming to some criteria. Otherwise, too many records may be returned by a query, causing serious performance issues. For example, you may want to look only at contacts that are buyers and not sellers. Access makes it easy for you to specify a query’s criteria.
Selection criteria are simply filtering rules applied to data as it is extracted from the database. Selection criteria instruct Access which records you want to look at in the recordset. A typical criterion might be “all sellers,” or “only those vehicles that are not trucks,” or “cars with retail prices greater than $45,000.”
Selection criteria limit the records returned by a query. Selection criteria aid the user by selecting only the records a user wants to see, and ignoring all the others.
You specify criteria in the Criteria row of the QBE grid. You designate criteria as an expression. The expression can be as a simple example (like “Trucks” or “Not Trucks”) or can take the form of complex expressions using built-in Access functions.
Character-type criteria are applied to Text-type fields. Most often, you will enter an example of the text you want to retrieve. Here is a small example that returns only product records where the product type is “Cars”:
Add tblProducts and choose ...