The steps in the section Add a validation rule to a control on a form, later in this article, explain how to add rules to the properties in individual controls.
Your validation rules can contain expressions — functions that return a single value.
When you define rules for tables, those rules apply when you import data.
To add validation rules to a table, you open the table and use commands on the Fields tab of the ribbon.
Validation text lets you provide a message to help users who input data that is not valid.
When data is entered, Access checks to see whether the input breaks a validation rule – if so, the input is not accepted, and Access displays a message.
Three types of cleaning methods are run during form processing.
Expressions can also perform mathematical operations. For example, the expression You can add a field validation rule and/or a record validation rule.By default, all .accdb and files use the ANSI-89 standard.