Use the Bound property to determine whether a value has been assigned to the parameter. Whenever a value is assigned to the TDBISAMParam object, the Bound property is automatically set to True. Set the Bound property to False to undo the setting of the value. The Clear method will replace the value of the parameter with NULL, but will not set the Bound property to False. If the Clear method is used to bind the parameter to a NULL value, the Bound property must be separately set to True.
TDBISAMQuery components use the value of the Bound property to determine whether or not to assign a default value for the parameter. If the Bound property is False, a TDBISAMQuery component attempts to assign a value from the data source indicated by the DataSource property of the TDBISAMQuery component.
The Bound property is ignored when the TDBISAMParam object is used with server-side procedures.