The Include blanks checkbox appears on query criteria screens for these criteria operators: Not Equal To, Not One Of, Less Than, Less Than or Equal To, Not Between, Not Like, and Does Not Contain. When the Include blanks checkbox is selected, the program includes blanks in the query results by adding the “or is blank” filter to the query condition. When the checkbox is cleared, the program excludes blanks from the query results by adding the “and is not blank” filter to the query condition.
Note: Query treats nulls as blanks. When you include or exclude blank values, this also includes or excludes null values.
The program is set to select Include blanks by default. Using Enable/Disable Default Blank Query Criteria, you can change this setting. It is important to remember that the enable/disable setting simply determines the default behavior for the Include blanks checkbox. You can always select or clear Include blanks on the individual criteria screen. This allows you to evaluate and handle queries on a case by case basis. If you later change the Enable/Disable Default Blank Query Criteria setting, it will not affect any queries created prior to the change.