DAO Property Types

In contrast to Access object properties, the three types of object properties are: built-in, system-defined, and user-defined.

• Built-in properties exist when the object is created, and like most of their Access counterparts, define the characteristics of the object itself. For example, Name and Type are examples of builtin properties.
• System-defined properties are those that Access adds to the object's Properties collection when it needs the property in order to work its magic. These are not Access database engine properties, but are created and used by Access.
• A user-defined property can be added to an object's Properties collection when you explicitly set a value to it. For example, a field's Description property is a user-defined property. Although you can set a value to it when you define the table, Access doesn't recognize that the property exists until after you've done so. In fact, after you've set its value, it appears in the field's Properties collection, but you still can't see it in the Object Browser.

Creating, Setting, and Retrieving Properties

Without even thinking about it, you've been setting and retrieving properties for as long as you've been programming. Whenever you check the value of a TextBox, or set the Enabled state of a command button, you are working with object properties. This section explores how to manipulate Access properties, object properties, and user-defined properties.

You can refer to built-in properties either directly through the object to which they belong or through the object's Properties collection. User-defined properties, on the other hand, do not form part of an object's type library, and thus are not available via that route, so you have to refer to them through the object's Properties collection.