Absolute Beginner’s Guide to Databases

An Overview of How Validation Rules Work in Databases

Databases support two levels of rules. The first level is at the field-level. Field-level rules are sometimes called field-level validations. For example, if the user should be prevented immediately from entering invalid data into a field, a field-level rule would be used. Have you ever entered data into a field only not to be able to get out of the field until you enter a valid value? This is an example of a field-level rule.

Field-level rules are often criticized because they tend to interrupt the flow of work. It can be quite aggravating to continually get interrupted with validation error messages prior to saving a record. This gets to a fundamental issue of whether field-level rules ...