I am planning to create a desktop app (Java or C# WPF) which would be used by multiple users. The requirements are such that a Graph DB like Neo4j fits perfectly into the scheme of things. I have done some investigations and it looks really good. I am working on the community edition. Now here is the problem. From what I have observed, I am able to make only one connection to the database. The moment I try to make a connection from another instance I get an error. Even accessing on localhost:7474 gives an error.
Is this by design? I understand that in a web App, I can still use a static reference to a single DB instance and work with it. But in a desktop app scenario how do I ensure that multiple users are able to access the database from their apps?
Your app instances can access the same neo4j server through its REST API. There is no need to directly connect to the DB.
Here is a page that shows you how to do that in Java.
Related
I have a Delphi-based client-server application. The server is a fairly simple application with a TRemoteDataModule. The client application connects to it via a TSocketConnection.
Everything is working fine on that front.
Is there a way to access the list of currently active connections for the TRemoteDataModule?
The reason I'm asking is because I would like to prevent users from connecting from more than one machine at a time to the same server, so I figured I would keep a list of usernames per connection and check against it whenever a new connection is attempted, or beforehand, client-side, via a a COM function.
Or should I be using some other mechanism altogether?
As an aside, is there a way to see which threading model and instancing model were used when creating the RDM? I'm not the one who created it, and I don't know where to find that.
Cheers!
Using Delphi XE5, if that makes a difference
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 a thinking of creating an iPhone/iOS app that would include a feature where one user could create a list of words and then save them to their account on a server. Also (and this is very important), the user could share their list with other users by giving them permission.
So my question is, how can I go about creating such a server? For right now, I have a home computer (running Windows XP that just stores data for my music system) which I can use to host the server. I am also open to the use of other online storage services like Google Drive or Dropbox (I can't remember if Amazon does anything like that). However (and I know this may complicate things a bit), but at least for now, I want/need to stick with free services/options.
Just to recap, the key features that I am looking for are:
create users/accounts (on the server)
eventually I may [try] to incorporate the use of other services to log users in like with their email account, OpenId, etc.
the ability to access (log in to) the server (with credentials) from my app
the ability to send/receive data between the server and my app
the ability to share data between users
I know this is a lot to ask for, but if anyone has any suggestions or can get me going in the right direction, it would be much appreciated.
The basic setup would be as follows:
Backend: Database (MySQL), Web server (Apache), with server side scripting (PHP).
Client: iOS device with developed app.
Communication: use HTTP client/server model, communicating with something like JSON.
This is much the same setup as a web server, but instead of serving html/css/javascript etc the results will be JSON.
As far as implementing specifics such as login in, and sharing data between users, this is purely dependent on your implementation. This is not trivial, and not something that can be easily stated in a single post.
Hope this helps.
You could build your own webservice in PHP, Ruby or Python. If you do so I would recommend building a RESTful webservice (http://en.wikipedia.org/wiki/Representational_state_transfer) and then use RestKit (http://restkit.org/) to handle the data in the iOS app. Especially RestKit's CoreData integration is nice in my opinion.
Another solution would be using a service like Parse (https://parse.com/products/data). The first million or so requests per month are free but after that it could get pricy. I personally have not tried it so I couldn't tell you if it is any good.
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.
I'm developing a tool that will comprise a central website and a desktop application. I've only really done entirely online developent, or entirely offline/client-side development before and not really had to link the two. I could use some help in how to approach passing data to/from the online site & desktop app.
The desktop app needs to communicate & do some control of iTunes, so initially I'm building this in Cocoa on OSX & making use of the ScriptingBridge framework.
On the website side I'm thinking of using Ruby on Rails, with data stored in a mySQL database, as I'm fairly familiar & seems like a good match for the online job it has to do. (But open to other suggestions if there's a better approach!)
I'm struggling to find the best approach to easily transfer data between the Cocoa app & the online rails database - is there a simple way of having the Cocoa app access the online database directly, or is it typical to dump some XML onto the webserver and have the app read that?
Opening a RESTful API on your RoR system is as simple as you can get. Have your desktop app communicate with that API using JSON or XML.
Advantages to using JSON rather than XML: (1) extremely simple to manipulate in Rails (2) extremely simple to work with in Javascript, should the need arise to build a web client in addition to the desktop one.
It's a very bad idea to have the desktop app communicate directly with your remote database. Two main reasons:
Security. Such a setup just begs to be hacked. Some databases are "built for the web" (CouchDB comes to mind) and would be alright here, but MySQL isn't.
Flexibility. With desktop application in the field, making changes and distributing them to all clients is hard. Should the need arise to change your schema, the web application layer frequently allows you to keep the interface with the desktop clients stable.