How can I easily delete all objects in a Realm

Question

I have the choice of doing a migration, but I would prefer to delete everything in my defaultRealm(). How can I do this easily?

realm.deleteObject(object)

is the only function along with .deleteObjects.

I have tried the following code:

Method 1

realm.deleteObjects(RLMObject.objectsInRealm(realm, withPredicate: NSPredicate(value: true)))

Method 2

        realm.deleteObjects(Dog.allObjectsInRealm(realm))
        realm.deleteObjects(Person.allObjectsInRealm(realm))
        realm.deleteObjects(Goal.allObjectsInRealm(realm))
        realm.deleteObjects(Goals.allObjectsInRealm(realm))

Both fail to prevent the migration exception.

Hey Captain, are you doing this on ios or android? Those methods do delete all the objects but you will still run into the migration issues. — yoshyosh, Oct 03 '14 at 20:27
A quick way to do this on simulator/phone is to just delete the app from the home screen — yoshyosh, Oct 03 '14 at 21:04

score 114 · Accepted Answer · edited Aug 24 '16 at 08:07

114

Use deleteAll():

let realm = try! Realm()
try! realm.write {
    realm.deleteAll()
}

edited Aug 24 '16 at 08:07

Ryan Brodie

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answered Oct 07 '14 at 20:37

jpsim

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Thanks, you guys should add that to the documentation! – CaptainCOOLGUY Oct 08 '14 at 03:09
1

This is documented in Realm's API docs: https://realm.io/docs/objc/latest/api/Classes/RLMRealm.html#//api/name/deleteAllObjects, which are more comprehensive than Realm's getting started documentation at https://realm.io/docs/objc/latest. – jpsim Nov 05 '15 at 18:34
4

I think the API changed a bit. For me to remove all objects using `RealmSwift`this worked: `try! realm.write { realm.deleteAll() }` – John B. Jun 07 '16 at 15:57
@JohnB. Updated answer. – Ryan Brodie Aug 24 '16 at 08:08
1

if the realm notification still running that time, it might cause crash, if directly use realm.deleteAll() – atom2ueki Mar 21 '17 at 07:41

score 16 · Answer 2 · answered Oct 23 '14 at 16:17

16

As of v0.87.0, there is a deleteAllObjects method on RLRealm that will clear the Realm of all objects.

answered Oct 23 '14 at 16:17

Michael McGuire

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@cesarferreira I recommend you file an issue with Realm (https://github.com/realm/realm-cocoa/issues) then. – Michael McGuire Dec 11 '14 at 16:52
@cesarferreira can you share the code in github issues? – yoshyosh Jan 15 '15 at 18:52
what do you mean with share github issue? – cesarferreira Jan 15 '15 at 19:07
If you can create a github issue you can copy and paste some code in there to show where it's not working for you – yoshyosh Feb 26 '15 at 18:00

score 11 · Answer 3 · answered Jun 03 '16 at 12:27

Things have moved on in the Realm world - in case anyone comes across this now, there is a property that can be set:

Realm.Configuration.defaultConfiguration.deleteRealmIfMigrationNeeded = true

It then does as advertised. (btw: a lot of the syntax above has changed in case you are trying any of the other methods)

The Github PR https://github.com/realm/realm-cocoa/pull/3463

score 5 · Answer 4 · answered Nov 08 '15 at 13:08

I think removing the Realm DB file is the valid answer considering that the question was about removing a whole storage rather than migrating it.

Here is a quick Swift code for that (as of Swift 2.1 and Realm 0.96.2):

if let path = Realm.Configuration.defaultConfiguration.path {
    try! NSFileManager().removeItemAtPath(path)
}

I use this code in the DEBUG version of the app if the migration error happens on loading the storage and then I recreate the storage. During development the schema can change a lot, so it would be too cumbersome to bother with migration all the time.

How can I easily delete all objects in a Realm

4 Answers4

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