You can write filter expressions to modify data returned from a query using the Advanced Query wizard and the Query editor. You can filter row data (one specific record in your database), group data (all grouped records), and all data results from the query.
Filter expressions are equations that include one or more of the following elements:
The typical format for a filter expression is variable=value, where variable can be a function expression, column, or query parameter; value can be a constant or query parameter; and = (equals) can be any operator.
For example, you might want to see sales data for a particular year. To do so, you can create a query of all sales totals that filters the results so only sales above specific amounts are in the result set: sales > 50.