Delete objects that does not belong from list - Realm

Question

I have a new list of objects to be saved/updated in realm. I want first to delete all objects stored in realm that is not included in my new list before saving/updating the new ones. Any idea on how to do this? (I don't want to delete all my table rows first then save the new ones)

Answer 1

First of all welcome to StackOverflow & please follow what @teun-van-der-wijst has mentioned in the comments.

Coming to your question,

In realm there is no specific function to UPDATE an object. There are 2 ways you can perform an update.

• Delete all the rows of the object and add the new ones. (But since you have mentioned that you do not wish to do this try option 2)
• Use the WRITE method to assign a new value to a existing property by using a filter or predicate.

You can follow this link for the documentation: https://realm.io/docs/swift/latest/#updating-objects

This is just a generic example of how to update using WRITE

let fruits = realm.objects(Fruits.self).filter("date = %@", removeTodaysItem)

let realm = try! Realm()
if let fruit = fruits.first {
    try! realm.write {
        fruit.date = "today's date"
    }
}