Once an attribute is created, its properties can be changed. There are several different changes that can be effected on an attribute.
Attributes can be renamed at any time, though attributes belonging to the same entity are not permitted to have duplicate names. Should a duplicate name be given, an error will occur and no change will occur.
Attributes each have a data type. Available data types are defined by Data Type Group. Once an attribute is defined, the datatype can be changed at any time. When selected, "Edit Attribute..." will prompt the user to select the new attribute data type.
Attributes can be deleted by right clicking on the attribute to be deleted. From the drop down menu, select Delete Attribute. A dialog box will appear asking for confirmation of the delete. Once the delete has been confirmed the attribute will be deleted. Note that if the attribute was a participant in a unique key, the attribute will then be deleted from the unique key. Should the deleted attribute be the only participant in a unique key, the unique key will consequently be deleted.
Attributes can be set to participate in a unique key constraint. See Set Unique Key Constraint for further information.