Fatal Error :Can't open realm

Question

I am working on IOS. I am using realm database in the frontend. It was working fine until I made some changes to the realm model and all files related to it. I just added one field to these files.

Now I am getting an error "Fatal error: Can't open realm" in the following code

fileprivate func getRealm() -> Realm {
    // get default configuration realm
    do {
        return try Realm()
    } catch {
        Swift.fatalError("Can't open realm")  //Fatal Error :Can't open realm
    }
}

Can anyone tell what might be the possible causes for this error. Thanks in advance.

Answer 1

If you made changes to the realm model, you need to increase your schema version and you may or may need to provide a migration block. See the official documentation for details.

// Inside your [AppDelegate didFinishLaunchingWithOptions:]

RLMRealmConfiguration *config = [RLMRealmConfiguration defaultConfiguration];
// Set the new schema version. This must be greater than the previously used
// version (if you've never set a schema version before, the version is 0).
config.schemaVersion = 1;

// Set the block which will be called automatically when opening a Realm with a
// schema version lower than the one set above
config.migrationBlock = ^(RLMMigration *migration, uint64_t oldSchemaVersion) {
    // We haven’t migrated anything yet, so oldSchemaVersion == 0
    if (oldSchemaVersion < 1) {
        // Nothing to do!
        // Realm will automatically detect new properties and removed properties
        // And will update the schema on disk automatically
    }
};

// Tell Realm to use this new configuration object for the default Realm
[RLMRealmConfiguration setDefaultConfiguration:config];

// Now that we've told Realm how to handle the schema change, opening the file
// will automatically perform the migration
[RLMRealm defaultRealm];