Dependency Status

JsonDB is a simple in process database to store, query and manipulate JSON documents for OS X (10.7+) and iOS (5.0+). It's built on top of the excellent FMDB which is an Objective-C wrapper around SQLite.

This project was born as a little private helper library in a toy OS X project where I needed to cache and query a fair amount of JSON documents. The library somehow evolved into a reusable standalone project.

I want to publish it as open source because I think it can be useful to someone else, but also to teach myself how to create and maintain a Pod, use Travis CI and use Specta and Expecta.

I hope you enjoy this project.


Since the 1.0.0 version this lib should be fairly stable and changes to the API (and storage schema) will be reflected by the Semantic Versioning.

JsonDB is coded in and designed for Objective-C, but it also works with Swift, you just need to add #import "JsonDB.h" in the Bridging Header. The API is still a kind of mess when called from Swift though, some help on that matter will be much appreciated.

Get Started

Try the demo app.

Or install the library and follow the example usage.

The documentation will be completed soon.


TL;DR: see the usage section if you only read code :)

The entry point in JsonDB is the JDBDatabase. You create an instance of JDBDatabase and specify to persist data on file or only in memory.

With an instance of JDBDatabase you then get a named JDBCollection which is a collection of documents (You can see JDBCollection as an SQL table).

With a JDBCollection you can insert and update documents. You can also create a JDBView, which is a queryable subset of JSON paths (You can see JDBView as an SQL view).

You can also query the JDBCollection directly, in which case a JDBView will be created on the fly for you, tailored for your query criteria and sort descriptor.

With a JDBCollection or a JDBView, you can create a JDBQuery by specifying a query criteria and sort descriptor.

In either ways, a JDBQuery will be created (you can see JDBQuery as a kind of SQL prepared statement). With a JDBQuery you can fetch the first document only or all the documents with an optional NSRange and/or projection. You can also (transactionally) batch remove and modify documents.

Finally, in JsonDB, a document is any objects graph compatible with NSJSONSerialization with a NSDictionary as the top level object.


The demo application is a generic database browser. It allows you to create/list collections, import JSON documents from URL, create/save/list/execute queries, create/save/list documents.

To run the demo application:

With pod try

In a terminal, simply execute:

$ pod try JsonDB

and run the target named JsonDB-Demo-iOS in Xcode.

With git clone

Clone the repository and run pod install from the JsonDB-Tests directory:

$ git clone
$ cd JsonDB/JsonDB-Tests
$ pod install

open the workspace:

$ open JsonDB-Tests.xcworkspace

and run the target named JsonDB-Demo-iOS in Xcode.



Download and unzip the project. Every file you need is under the JsonDB directory. But, you will also need to install the dependencies manually.


After adding the pod (or installing the library) to your project, just import it:

#import "JsonDB.h"

and follow the example usage.


JsonDB needs OS X (10.7+) or iOS (5.0+).

It also needs FMDB which is automatically installed if you use CocoaPods (you do right ?).


Open a database at the specified path (here, on iOS, main.jsondb in the application's Document directory will be created if it does not exists)

NSString *dbPath = [[NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) firstObject] stringByAppendingPathComponent:@"/main.jsondb"];
JDBDatabase *database = [JDBDatabase databaseAtPath:dbPath];

Get a collection of document (will be created on the fly if it does not exists)

JDBCollection *collection = [database collection:@"GameScore"];

Insert schema less documents into the collection (an id will be auto generated for each document since they do not have one)

[collection save:@{@"playerName": @"Sean Plott", @"score": @1337, @"cheatMode": @NO}];
[collection save:@{@"playerName": @"John Smith", @"score": @9001, @"cheatMode": @NO}];
[collection save:@{@"playerName": @"John Appleseed", @"score": @1234, @"cheatMode": @YES}];

Find who is cheating (this will returns an array of document)

NSArray *cheaters = [[collection find:@{@"cheatMode": @YES}] all];
expect(cheaters[0][@"playerName"]).to.equal(@"John Appleseed");

Find the players named John ordered alphabetically

NSArray *johns = [[collection find:@{@"playerName": @{@"$like": @"John %"}} sort:@[@"playerName"]] all];
expect(johns[0][@"playerName"]).to.equal(@"John Appleseed");

Find the first one with a score over 9000, flag it as a cheater and return the old document

NSDictionary *over9000 = [[collection find:@{@"score": @{@"$gt": @9000}}] firstAndModify:^JDBModifyOperation(NSMutableDictionary *document) {
    document[@"cheatMode"] = @YES;
    return JDBModifyOperationUpdate | JDBModifyOperationReturnOld;


Pierre-David Bélanger,


JsonDB is available under the MIT license. See the LICENSE file for more info.