Join information about other object classes

By defining one or more JOIN s, you can add objects from other object classes that are related to the base class through relationships defined in the meta-model. If you do not join other object classes to your Alfabet query, you will only find and display objects in the base object class in the Alfabet query results.

Relationships to other object classes are specified in object class properties of the type Reference or ReferenceArray . A reference stores the value of the REFSTR property of the referenced object.

If a report should display all application groups that the application is assigned to, you cannot simply add the property ApplicationGroup to the show properties of the Alfabet query because you would then get a list of REFSTR values for internal database identification of the reference:

To display the name of the referenced application groups, you must add a JOIN to the Alfabet query. The join specifies that application groups are added to a query result if they are referenced in the object class property ApplicationGroups (Application Groups).

The properties of the object class ApplicationGroup (Application Group) are then displayed in the property selector of the Alfabet Query Builder and you can add the property Name of the class ApplicationGroup to the show properties.

If multiple application groups are referenced by the application, a separate line is displayed in the results for each relation found: