realm, check schema version

问题

I'm using Realm for Android, I'm wondering how to get the current schema version. In their Migration example, the version is incremented then saved, but I need to check the version before doing any upgrade. Thanks.

回答1:

You can use the below code to get the current schema version of Realm before migration.

Realm.init(context);
RealmConfiguration realmConfig = new RealmConfiguration.Builder().build();
DynamicRealm realm = DynamicRealm.getInstance(realmConfig);
long version = dynRealm.getVersion();//this will return the existing schema version
dynRealm.close();

回答2:

In the Migration class from the example, you can see that they check for every version. The version parameter is the current version of the current realm. If you notice that after every if statement, the version is incremented.

if (version == desiredVersion){
   //Migration script
   version++;
}

In any way, you will need to write migration scripts for all versions whose changes need migration. Otherwise, the app will be crashed.

来源：https://stackoverflow.com/questions/31419803/realm-check-schema-version