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Isar Database

🚧 Alpha version - Use with care. 🚧

QuickstartDocumentationSample AppsSupport &

Isar [ee-zahr]:

  1. River in Bavaria, Germany.
  2. Database that will make your life easier.


  • 💙 Made for Flutter. Easy to use - zero configuration
  • 🚀 Highly scalable from hundreds to hundreds of thousands of records
  • 🔎 Full-text search. Make searching fast and fun
  • 📱 Multiplatform. iOS, Android, Desktop and the web (soon™)
  • 🧪 ACID semantics. Rely on consistency
  • Asynchronous. Parallel query operations & multi-isolate support
  • 💃 Static typing. Compile-time checked and autocompleted queries
  • 🔒 Strong encryption. Optional authenticated AES-256 GCM encryption

1. Add to pubspec.yaml

  isar: 0.4.0
  isar_flutter_libs: 0.4.0 # contains the binaries
  isar_connect: 0.4.0 # if you want to use the Isar Inspector

dev_dependencies: isar_generator: 0.4.0 build_runner: any

2. Define a Collection

class Post {
  int? id; // auto increment id

@Index(indexType: IndexType.words) // Search index String title;

Links comments; // Link to other collection }

3. Open an instance

final isar = await openIsar();

Isar Inspector

The Isar Inspector allows you to inspect the Isar instances & collections of your app in real time. You can execute queries, switch between instances and sort the data.

CRUD operations

All basic crud operations are available via the IsarCollection.

final newPost = Post()
  ..title = 'Amazing new database'
  ..comments = ['First'];

await isar.writeTxn((isar) { await isar.posts.put(newPost); // insert });

final existingPost = await isar.get(!); // get

await isar.writeTxn((isar) { await isar.posts.delete(!); // delete });


Isar has a powerful query language that allows you to make use of your indexes, filter distinct objects, use complex

groups and sort the results.
final isar = await openIsar();

final databasePosts = isar.posts .where() .titleWordBeginsWith('DaTAb') // use case insensitive search index .limit(10) .findAll()

final postsWithFirstCommentOrTitle = isar.posts .where() .filter() .commentsAnyEqualTo('first', caseSensitive: false) .or() .titleEqualTo('first') .findAll();


You can easily define relationships between objects. In Isar they are called links and backlinks:

class Teacher {
    int? id;

String subject;

@Backlink(to: 'teacher')
final students = IsarLinks<student>();


@IsarCollection() class Student { int? id;

String name;

final teacher = IsarLink<teacher>();



With Isar, you can watch Collections, Objects, or Queries. A watcher is notified after a transaction commits successfully and the target actually changes. Watchers can be lazy and not reload the data or they can be non-lazy and fetch new results in the background.

Stream collectionStream = isar.posts.watchLazy;

Stream> queryStream =;

queryStream.listen((newResult) { // do UI updates })


Copyright 2021 Simon Leier

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

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