myNWT is a Relational Database application. This means there is a parent child relationship between items. For example an owner to their dog(s). The owner is the parent and can be related to one or more dogs who are the children.
Shows, Trials, Classes and Entries also have a parent child relationship. For example a show has one or more trials. A trial has one or more classes. A class has one more entries.
These relationships create a hierarchy or structure. Understanding this hierarchy is important especially when deleting a record. For example if I delete a trial I will delete the classes that are children of that trial which will delete the entries that are children of those classes. The show will not be deleted because it is the parent of the trial and not a child of the trial. Another example is deleting a person that is the owner of a dog. If there person was deleted the dog would be orphaned for this reason a dog must be assigned a different owner or be deleted first.
With all that said it is rarely necessary to delete something from the database. Actually you want to keep as much information n your database for archive purposes, so it can be referenced later if needed.
If you do need to delete something it must be done from the details page using the delete button in the ribbon. This deletes things in the correct order, so nothing is orphaned.
Shows, trials, and classes can be put in a closed status, since you are normally only working with current ongoing shows.
The details pages can be filtered and are filtered on open by default.