Open & Close a Realm - React Native SDK

Overview

Realms are the core data structure used to organize data in Realm Database. At its core, a realm is a collection of the objects that you use in your application, called Realm objects, as well as additional metadata that describe the objects.

This page details how to configure and open a realm using the React Native SDK.

Key Concept: Realm Files

Realm Database stores a binary encoded version of every object and type in a realm in a single .realm file. The file is located at a specific path that you define when you open the realm.

Open a Local Realm

To open a local (non-synced) realm, pass a Realm.Configuration object to the asynchronous method Realm.open().

const Car = {
  name: "Car",
  properties: {
    make: "string",
    model: "string",
    miles: "int",
  },
};
// Open a local realm file with a particular path & predefined Car schema
try {
  const realm = await Realm.open({
    schema: [Car],
  });
  realm.close();
} catch (err) {
  console.error("Failed to open the realm", err.message);
}

Open an In Memory Realm

const realm = await Realm.open({
  inMemory: true,
  schema: [Car],
});

Close a Realm

It is important to remember to call the close() method when done with a realm instance to avoid memory leaks.

realm.close();