Creating custom validation rules in Microsoft Access helps enforce data integrity by restricting the types of data users can enter into fields. Here’s how to do it:
- Right-click the table in the 'Navigation Pane' and choose 'Design View'.
- Click the field you want to validate.
- In the Field Properties pane, locate the 'Validation Rule' property. Click the ellipsis icon.
- Enter your custom validation rule as an expression. Click 'OK'.
- Enter a message in the 'Validation Text' property to display when the rule is violated.
- Click 'Save' to save your changes and test the rule.
