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Bound, Unbound, and Calculated Controls

There are important differences between bound and unbound controls.

Unbound controls display information to the user or gather information from the user that's not going to be stored in your database. Here are some examples of unbound controls:

• A label providing instructions to the user

• A logo placed on a form

• A combo or text box placed on a form so that the user can enter report criteria

• A rectangle placed on the form to logically group several controls

Bound controls are used to display and modify information stored in a database table. A bound control automatically appears in the form specified in its Display Control property; the control automatically inherits many of the attributes assigned to the field that the control is bound to.

NOTE

The Display Control property is set in the design of the underlying table. Located on the Lookup tab of the Table Design window, it determines the default control type that is used when a control is added to a form or report.

A

calculated control is a special type of control that displays the results of an expression. The data in a calculated control can't be modified by the user. The control's value automatically changes as the values in its expression are changed. For example, the Sales Total changes as the Price or Quantity is changed.