Update statement in Realm android

Question

How should i update a already existing value using realm DB in android?

I have been trying to update it but it is adding as a new value only not overwritting it

Please show us your efforts(the relevant part of your code, where you are trying to update). Only then we can tell you where's the problem. — DroidDev, Dec 01 '14 at 07:37
**see full answer with example http://stackoverflow.com/questions/30933229/update-realm-object-android** — N J, Aug 04 '15 at 14:22

score 40 · Accepted Answer · edited Jan 10 '17 at 15:52

40

Another way to update an existing object with all its fields in your Realm DB is using the method realm.copyToRealmOrUpdate():

Object obj = new Object();
obj.setField1(field1);
obj.setField2(field2);
realm.beginTransaction();
realm.copyToRealmOrUpdate(obj);
realm.commitTransaction();

If your object has a Primary Key, this method will update the object automatically without duplicate objects :)

More info: copyToRealmOrUpdate()

edited Jan 10 '17 at 15:52

SolArabehety

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answered May 26 '15 at 09:16

j_gonfer

1,547
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1

You actually don't get any benefit from beginning the transaction before you have your object created. So I would suggest to move that first line down before the copyToRealmOrUpdate() to make it clear. – bmunk May 28 '15 at 21:21
This answer is outdated? `realm.copyToRealmOrUpdate(obj);` is not needed if you are working with realm. It would be needed only if you are using Retrofit for example: https://realm.io/docs/java/latest/#retrofit – Micro Nov 03 '16 at 20:56
2

@MicroR So, what is the alternative? How to update an existing value in Realm? (I'm getting `Realm Database Error: Value already exists:` if I use `createObject()`). – Srikar Reddy Nov 13 '16 at 20:17
What if i don't have a primary key and I still want to update? – Parag Kadam May 20 '17 at 10:40
2

From documentation: "Using primary keys makes it possible to use the copyToRealmOrUpdate() method, which will look for an existing object with this primary key, and update it if one is found" – Vinicius Lima Jul 09 '17 at 19:09
@SrikarReddy u because not need a createObject for update.. make a simple constructor with all variables a use createOrUpdate and do not forget realm.close – marlonpya Jul 31 '17 at 02:15
is it necessary to use try catch block? – Zahidul Feb 13 '18 at 15:35

Saurabh · Answer 2 · 2021-04-22T12:08:19.393

9

You can use insertOrUpdate method to do this.Hope this helps

  Realm.getDefaultInstance().executeTransaction(new Realm.Transaction() {
                @Override
                public void execute(Realm realm) {

                    objectToEdit.setNewValue("string");
                    realm.insertOrUpdate();
                }
            });

edited Apr 22 '21 at 12:08

answered Feb 09 '17 at 12:04

Saurabh

975
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score 0 · Answer 3 · answered Jun 18 '20 at 09:58

Realm realm = Realm.getDefaultInstance();
    OrderedRealmCollection<Practice> orderedRealmCollection = 
             realm.where(Practice.class)
            .contains("key", "matchig value")
            .findAll();

    if(orderedRealmCollection.size()!=0){
        Practice practice = orderedRealmCollection.first();
        Realm.getDefaultInstance().executeTransaction(new Realm.Transaction() {
            @Override
            public void execute(Realm realm) {
                practice.setUpdate_practice_steps(""+steps);
                realm.insertOrUpdate(practice);
            }
        });
    }

Update statement in Realm android

3 Answers3

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