Question

When using Microsoft Visio or Access, what is the importance of data validation, and how can user data entry errors be reduced or eliminated?

Answer 1

1.Your Access database is only as sound as the data it stores. Data types can only do so much. The next step is to constrain input values using validation rules.

2.Protecting the validity of your data is one of the most important tasks of a database developer. To ensure that users enter accurate data, start at the foundation. By using validation rules, you can ensure accurate data entry (to a point).

3.

Validation rules catch errors at the data entry level, so in effect, the mistakes never make it into your database. If the data doesn't satisfy the conditions you've set, Access won't accept the input value. You don't have to catch anything later and correct it, so validation rules are more efficient than cleaning up after the fact.

4.You can apply a validation rule to a field or to a record. At the field level, the rule checks the data for only the field constrained by the rule.

5. For example, you might restrict an hours worked field to values between 0 and 40 (inclusive). To do so, you'd use the following expression on an Integer field: <=40 And >=0. When a user enters a value other than 0 through 40, Access displays an error message and rejects the input value.