A little design question here:
The requirements for the system go as follows:
all the content is stored on the backend in a database
the client(mobile app) downloads all of the data to have a local copy for offline access
The database on the backend is quite complex and contains entities/fields which are not(at least not currently) used in the mobile client.
What is the right way to design the local database ? Do I need to create a mirror copy of the backend database on the client ? Do I need to create my own data model regardless of what is on the backend ? Should there be any similarities between the two data models at all ?
Related
I have been working on iOS application for sometime, and I am using Core Data to manage the SQLite database for the application. The users of the application can update the data associated with their account using the application, but I would like to create a simple web form where users could update certain information asosciated with their account. Basically I would like a user to be able to access a web adress from their personal smartphone or computer, login, then update information asociated with the account stored on the iOS device. What are the possible solutions I could use to accomplish this?
Breaking down your question:
Currently you have an iOS app which uses a local SQLite DB to store data
You want to let users update information in this DB remotely (i.e, via a web site)
Unfortunately to do this you're going to need to make some significant changes to how your app works. This is because it's impractical - if not nearly impossible - to do this kind of thing and keep the database local to your device.
The standard way of achieving this would be to store your database remotely on a web server, and then have both your app and your web form interact with this server to retrieve and update data.
There are lots of different ways to do this. Fundamentally, you'll need a server running a database, and a web service to access it. You could implement this yourself, using something like MySQL or PostgreSQL, along with a language of your choosing (Ruby, PHP, Node, etc). Another option is to use one of several 'backend as a service' providers. These are companies that provide 'out of the box' backend functionality for mobile apps. Two popular providers are Parse (owned by Facebook) and Stackmob.
Whether you choose to do it yourself or use a backend provider will depend on how confident you are. It's not an especially hard or tricky thing to put together on your own, but there are several common pitfalls you're likely to encounter.
I am planning to build an iOS app with using DB(Ms-Sql).
However, people recommends not to access DB from Xcode.
They recommend me to use php or asp for accessing db through a webpage.
I want to know the reason.
Also I am going to use DB only for (view) select line (not insert, update nor delete).
so is it possible to access directly to db for viewing purpose only?
thank you
It's generally bad for an application (mobile, web, any client) to directly have access to any database for security issues. Clients really should not be accessing the database, which is often holding very private/secure data. It opens up vulnerabilities (i.e., sql injection attack).
A set of web services written in php or java or some back-end technology is a more secure, scalable system. These web services can connect to the database and retrieve data. Your iOS application can call the web services and receive the data..for example in the form of XML or JSON.
Currently I am using MySQL + RoR combination for storing data of my iOS application.
I use Core Data for offline storage.
So I have made a lot of APIs or various CRUD like operations.
Given the fact that Mongo stores entities as JSONs, and it also has a REST interface, is it possible to use Mongo without a web service in front of it to store data using its own REST API?
If No then whats the problem? Is it because of security concerns or its not possible at all.
If Yes, is it OK ?
Both concerns that you've raised are valid:
The MongoDB --rest feature is a simple readonly interface (no support for insert/update/remove operations).
It's also poor practice from a security point of view to expose your database server directly on the internet.
Suggested approaches would be to either:
1) Use (or build) a secure REST API for your application
2) Use a hosted MongoDB service that provides a secure REST API.
I am new to iOS app development and am interested in developing an app that needs to utilize existing technologies to sync app specific data across multiple i-devices (iPhone, iPad, Touch, etc.). As an example, the app can be installed on multiple devices. On one device, the user will initially create an account. Then in subsequent logins, the user may create a task list, and each task item may possibly include a captured photo image. On the user's second i-device, as he logs in, he would be able to see and access the list and images (locally). Can someone explain to me what technologies I can leverage on to implement such an app?
Specifically:
How do I set up and manage the user accounts? Do I Need a dedicated server and sql database set up for my entire user base? And what programming/scripting languages do I need to learn?
How about the mechanism of pushing and pulling app data from one device to another? Do I need some kind of cloud technologies (SaaS?) to handle the storage and transferring of the data?
Any specific open source or commercial products I can leverage on?
Thanks in advance.
Kenny
I personally have not have had a situation like this, but here is what I would recommend.
You will need to have a server set up with database software.
You will need to write an api for yourself based on HTTP POST (REST) or maybe you could write a SOAP service.
I would HIGHLY recommend purchasing an SSL cert. for your server that way you can send the username and password in your request and it will be encrypted automatically.
For the api, you have a whole selection of languages and databases at your disposal. I am personally biased towards asp net with an MSSQL server.
with your api you will need to write methods to authenticate the user, and then save and send your data.
In your app you will simply send web requests to the server (ASIHttpRequest maybe?) and you can receive JSON responses back, which you can then deserialize into workable objects and vice versa.
if you do use asp net, you can use the newtonsoft JSON library to convert your objects for sending and convert received objects.
I dont remember the name, but there also is a JSON library for obj-c that is usable on iPhone.
Use a SQL server and host a database of logins and passwords.
Then, from each device, create a connection to the server, and download the login information for the account.
Also, not to be rude but: Google it.
I currently develop an iOS app for a local business directory, and I use SQLite. This sadly means I must do several hours of data entry when new businesses are added and push the updated DB out, because the desktop site uses the Joomla CMS.
Obviously companies that provide directory services don't have to worry about such things. How do they do it? Core Data accompanied by a screen scraper?
PS. I apologise if this question is inappropriate to be asked on StackOverflow, I didn't know where else to ask.
Generally these companies have a client/server architecture where the data lives on a centralised server and the mobile apps pull the data through an exposed API over the internet.
To replicate this yourself, you would have a server with all the data and expose it through an API/web service (so you'd need to think about authentication and security) which your mobile app pulls from when it needs to update the database or just have the query sent to the web service and return the appropriate results so the database does not live on the iOS device itself. The downside to the first approach (updating the DB) is you'd need to wait for the DB to fully update before the user could use the application and the downside to the second approach is to make queries, the client would need an active internet connection.
The first thing you'd want to look at is if/how you can expose the data stored in the Joomla CMS through an API (XML/JSON?)