Up until now, we have discussed how data is displayed in a table (formatting) and what type of data may be placed in a record’s field (input mask). However, we haven’t discussed whether a user must type in data.
One way to keep your database data clean is to disallow the creation of a record unless all of the required fields have some type of data in them. For example, you wouldn’t want a user of your database to create a new customer record unless all of the data for that customer is placed in the record. For example, you don’t want to come back to your database and find that a customer placed an order but you have no address, order number, etc. for that customer.
Access 2007 solves this problem by allowing you to require that certain information is placed in a record before the data can be saved. Otherwise, the record is not created. The required property of a table has two settings: Yes, means that a user cannot create a record unless something is placed in the field in question. No (the default property) means that the field for a record may be left empty. By manipulating the required property of a field, you can better ensure that your database will be complete.