Validating a text field
Keep in mind that Access supports two sets of wildcard characters: ANSI-89 and ANSI-92.
Each of those standards uses a different set of wildcard characters.
Syntactic validation should enforce correct syntax of structured fields (e.g.
SSN, date, currency symbol) while semantic validation should enforce correctness of their values in the specific business context (e.g.
Input validation should happen as early as possible in the data flow, preferably as soon as the data is received from the external party.
A record validation rule checks input to one or more fields is applied when the focus leaves the record.Typically, your database is easier to use if you use IS NOT NULL and enter a friendly message in the Validation Text property.You can use wildcard characters in your validation rules.To add validation rules to a form, you open the form in Layout view and add rules to the properties of individual controls.The steps in the section Add a validation rule to a table explain how to add validation rules to table fields.