way to purge all but one object types (models) in a realm

问题

I want to realm.delete() all but one model in my realm. Is there any way to do this without listing all of them?
Maybe a way to loop through all the types currently existing in a realm?

回答1:

You can access the types from your Realm configuration, filter them to exclude the one you want to keep than delete each object of each type that you don't want to keep.

let typeToBeKept = MyObjectClass.self
realm.configuration.objectTypes?.filter{$0 != typeToBeKept}.forEach{ type in
    try! realm.write {
        realm.delete(realm.objects(type.self))
    }
}

来源：https://stackoverflow.com/questions/45791715/way-to-purge-all-but-one-object-types-models-in-a-realm