CODEWITHSUNDEEP
androidrealm
ChaturaM
ChaturaM

Reputation: 1557

Set value to a realm object

I have following class

public class Student extends RealmObject{
private int studentID;
private String studentName;

// getters and setters here

}

Then I try to set a value to a already created student object

student.setStudentName("Peter");

Then I get following error

java.lang.IllegalStateException: Mutable method call during read transaction.

In order to overcome this I have to do it as follows

Realm realm = Realm.getInstance(this);
realm.beginTransaction();
student.setStudentName("Peter");
realm.commitTransaction();

I don't want to persist this change in the database. How can I just set/change a value to an realm object variable without always persisting it to the database?

Upvotes: 14

Views: 7337

Answers (4)

Zugor
Zugor

Reputation: 881

You might want to create a new Model. And your new model should implement RealmModel.

public class StudentRM extends RealmModel{
private int studentID;
private String studentName;

// Constructors here
// getters and setters here

}

Now you can do this.

studentRm.setStudentName("Peter"); //Setting Vale Or
studentRm.addAll(student); //Add all value from DB
studentRm.setStudentName("Jhon"); //It won't change DB anymore
studentRm.getStudentName(); // "Jhon"

Upvotes: 1

EpicPandaForce
EpicPandaForce

Reputation: 81588

If you want to modify the object in a non-persisted manner, you need an unmanaged copy of it.

You can create a copy using realm.copyFromRealm(RealmObject realmObject); method.

Upvotes: 7

darksider
darksider

Reputation: 1030

You can use realm.cancelTransaction();, instead of realm.commitTransaction();

Upvotes: 0

geisshirt
geisshirt

Reputation: 2497

When you are using Realm.createObject(), the object is added to the Realm and it only works within a write transaction. You can cancel a transaction and thereby discard the object.

Moreover, you can use your model class as a standalone class and create objects in memory (see http://realm.io/docs/java/0.80.0/#creating-objects for details). If you need to persist the objects, you can use the Realm.copyToRealm() method.

Upvotes: 4

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