I would like to read/write data from my Oracle DB into my iPhone code.
Can you suggest some methods for the same?
One possible solution is provide your iOS App a REST Api and implement methods to read/update/delete your model entities.
If you could access a database directly from your iOS App, for every change in your model you had to deploy a new version on your iOS App. Providing a REST Api you can made changes in your model and do not change parameters or response on your services.
Don't.
Database connections generally expect to be reliable. Connections from an iPhone aren't.
Also, any DB administrator would tell you that the first step to ensuring database security is to lock down the number of places from which the database can be directly accessed. This is why you never (or should never) see client devices talking directly to a database.
Instead, implement an intermediary (such as a web service) that accepts, e.g., HTTPS connections from the iPhone in the usual manner (NSURLConnection, etc.) and does the actual database heavy lifting itself. I'm not an Oracle expert, but I would assume that they have some products that help you do this with relatively little effort given how common a task it is. If not, it should be fairly straightforward for you to implement your own in Java, Python, or a language of your choosing.
Related
I would like to give a web app with a PostgreSQL database 100% offline functionality. In an ideal case the database should be completely replicated in the browser per user, and synchronized when online. So that the same code can be used to talk to both the offline and online database. I know this is possible with PouchDB and CouchDB, but have not found a solution that works with PostgreSQL. Is this at all possible?
Short answer: I don't know of anything like this that currently exists.
However, in theory, this could be made to work...(long answer:)
Write a PostgreSQL backend for levelup (one exists for MySQL: https://github.com/kesla/mysqldown)
Wire up pouch-server to read/write from your PostgreSQL db using pouchdb's existing leveldb adapter (which in turn will have to be configured to use your postgres backend). Congrats, you can now sync data using PouchDB!
Whether an approach like this is practical in reality for your application is a different question you'll have to answer.
You may be wondering, for example, "will I be able to sync an existing complex schema with multiple tables to the client with this approach?" The answer is probably not - the mysqldown implementation of leveldown uses a single MySQL table with three fields: id, key, and value (source), and I imagine any general-purpose PostgreSQL adapter would be similar (nothing says you can't do a special-purpose adapter just for your app though!).
On the other hand, if you were to implement a couchdb-compatible API (or a subset- you may not need attachments, for example) over your existing database schema, there's nothing stopping you from using PouchDB on the client to talk directly to that as if it were an actual CouchDB - just pop in the URL and call replicate()! Implementing the replication protocol might be a fair bit of work, since you'd need to track revisions and so on somewhere - but again, technically not impossible!
There are also implementations of levelup's backend storage that are designed for browsers. See level.js, which could be another way to sync between a server-side Postgres levelup backend and the browser.
TL;DR: There's tons of work being done around Javascript databases right now. Is syncing with Postgres impossible? probably not. Would it be a lot of work? Definitely. Worth it? Who knows, but it would be cool.
Without installing PostgreSQL on the client? No. Obviously you can cache data for offline use, but an entire RDBMS+procedural languages in Javscript, no.
I have a rather simple idea for an iPhone app. What I need to accomplish:
Allow login of users (which means I'll have to store usernames, passwords, and other account info).
Allow users to submit strings that other users can view.
Attributes attached to each string that must be tracked (i.e. "votes, views, comments, etc.).
As such, I assume I'll need to start learning about databases and working between a server and client. I've gotten my feet wet in OSX/iOS programming (specifically Objective-C) before. I want to learn how one can accomplish a data-based application and the needs I listed above.
I've done some light research and discovered something called SQLite (free and open-source is always good). Is this the right path to achieve what I want to do? I'm a total "noob" when it comes to this field of server/client/data "stuff".
Your help is greatly appreciated.
SQLLite is more like a local database. Really, the database that you will use is unimportant. It sounds like a project with webservices. Inside your webservices, you might connect to a Microsoft SQL Server or anything you want.
I think you should study how to setup a webservice that can be accessed in your code. Webservices is not an Objective-C topic, it applies to any platform. Your project is more like a web development project.
You can save user's credentials in keychain.
#Kinderchocolate is right about introducing database into your project.
It hears about a app which need transmitting data among clients.It means your need server database and local database.
For server database,I recommend you to use Parse.Parse is a platform which provide a convenient way to use their server database with Objective-c in your app.This tool will save many times and energy(it's not necessary to learn PHP,Apache,Mysql).Parse is not free of course,but it has a free period and enough for you to examine your idea.
Here's Parse!.
For local database,I recommend you to use Core Data,Which is provided by XCode.Core data is so strong to meet your need.You can find a way to use Core Data in many books.
Go try Firebase for database in the cloud. (On the server). In Swift 4 there is complete support for Firebase and SQLite
Okay, so I'm currently developing an iphone app that I plan to take into production and scale. I'm a bit lost on the whole subject.
What is better to use: core data or sqlite? (as the local DB)
Also, can sqlite be used exclusively to communicate with my remote server as well? At first I thought it could but I've been reading that sqlite isn't great to use on servers that get a massive amount of hits.
I've read that oracle, mysql, or mssql may be better to use on a remote server and that I can communicate with these servers via REST or SOAP.
I plan to be able to both read and write to a remote server. The files transferred will mostly be small data objects and pictures. Speed is of the essence, so I'd like to know which options are my fastest routes. Of course, I want the option to scale and not have performance take too much of a hit as well.
On the subject of Core Data vs sqlite see this question.
SQLite is a small and lite embedded SQL database engine. It's not meant to used in server environments. In general, it's not a good idea to communicate directly over the Internet. It's more common to have some sort of process logic between the client code and the database to do a range of things like validate input, process business logic, security, etc. You can implement this sort of layer in REST, SOAP, or whatever you like. Since your clients will be mobile devices, a http based web service (like REST or SOAP) is a good idea as all mobility platforms have inbuilt API support for http messaging. There are lots and lots of options on the server depending on what type of server you want to setup and run with.
If your new to this, maybe you should read something like 'Patterns of Enterprise Application Architecture' by Martin Fowler to get a idea of what sort of design patterns people use to implement the server side layering.
Let me start by saying: this is my 1st post here, this is a bit lenghty, and I havent done Windows Forms development in years....with that in mind please excuse me if this isn't directly a programming question and please bear with me as I really need the help!!
I have been asked to develop a Windows Forms app for our company that talks to a central (local area network) Linux Server hosting a PostgreSQL database. The app is to allow users to authenticate themselves into the system and thereafter conduct the usual transactions with the PG database. Ordinarily, I would propose writing a webforms app against Mono, but the clients need to utilise local resources such as USB peripheral devices, so that is out of the question. While it might not seem clear, my questions are italised below:
Dilemma #1:
The application is meant to be always connected. How should I structure my DAL/BLL - Should this reside on the server or with the client?
Dilemma #2:
I have been reading up on Client Application Services (CAS), and it seems like a great fit for authentication, as everything is exposed via URIs. I know that a .NET Data Provider exists for PostgreSQL, but not too sure if CAS will all work on a Linux (Debian) server? Believe me, I would get my hands dirty and try myself, but I need to come up with a logical design first before resources are allocated to me for "trial purposes"!
Dilemma #3:
If the DAL/BLL is to reside on the server, is there any way I can create data services, and expose only these services to authenticated clients. There is a (security) requirement whereby a connection string with username and password to the database cannot be present on any client machines...even if security on the database side is quite rigid. I'm guessing that the only way for this to work would be to create the various CRUD data service methods that are exposed by an ASP.NET app, and have the WindowsForms make a request for data or persist data to the ASP.NET app (thru a URI) and have that return a resultset or value. Would I be correct in assuming this? Should I be looking into WCF Data Services? and will WCF work with a non-SQL Server database?
Thank you for taking the time out to read this, but know that I am desperately seeking any advice on this! THANKS A MILLION!!!!
EDIT:
I am considering also using NHibernate as my ORM
Some parts of your questions are complicated and beyond my expertise. However, in general you can do almost anything you put effort into, CAP theorem and the like aside.
DAL/BLL stuff in general can reside in any of the tiers. I put a lot of this in my database and some in the middle tier, however this is to allow re-use in different environments which may or may not be a goal for you. The thing is I would think through carefully the separation of concerns issues here and what sorts of centralization of logic you want to place. The further back, the more re-usable this becomes but this is not always a free tradeoff.
I am not entirely familiar with CAS but it looked like AJAX kinds of stuff from what I saw on the MSDN web site. That could be wrong, but if it is right, then you have an issue in that such requests may be stateless and this could be an issue if you need a constant connection.
On the whole based on what you are saying it sounds cleanest to do a two tier rather than a three tier app, and have the DAL/BLL sit on the client, possibly supported by stored procedures in the server. You can then set PostgreSQL up to authenticate against whatever you use on your network (KRB5 if AD is what I would recommend). This simplifies your data access, and it allows you to control permissions based on the authentication against the database. Since you can authenticate users based on AD, you can then set permissions accordingly.
One important consideration is going to be number of connections. PostgreSQL does have some places where every current connection must be checked and iterated through, and connection startup and tear-down overhead in some cases can be significant. So one important decision will involve connection pooling. Whether or not you use connection pooling to boost performance will depend on what you are doing but I have seen cases where PostgreSQL has handled 600 connections without serious problems.
I'm writing a game for iPhone, and I want an online leaderboard using mySQL, which i'm very familiar with.
How do I implement this in my app?
I would assume there's a framework/library i need to obtain?
You don't.
You most certainly DO NOT want to expose and publish your database connection to the "live" internet. That's simply folly.
The database listeners simply aren't designed to work over such an unrestricted domain. They tend to live sheltered lives.
Instead, you should front your database with another service that IS designed for the wilds of the internet. This service can handle the authentication, encryption, load balancing, etc. requirements that good internet servers support.
Most folks today use some variant of web service, posting XML or JSON, but you can do whatever you want.
But don't open the DB connection to the live internet. You're just asking for trouble.
You should abstract the DB technology from the app, wrap your MySQL DB with a simple web service and run it on a web server, then you can use standard HTTP requests to interact with your database from your app.
My suggestions (not by any means the only way to do this)...
Use Django (or some other simple web framework) to wrap your database model, you can ever have django generate the code from your existing DB schema.
Write a few basic views to modify your DB using basic HTTP POST calls and send the username and score data in the POST data
Write a few simple pages that return the data you want in an XML format that you app can parse and display however you want, these are essentially just very simple generated web pages.
Now you have a publicly accessible leaderboard server that your app can interface with by posting scores and retrieving data through simple socket HTTP calls.
This may be outside your scope, but have you considered using OpenFeint instead to do Leaderboards and more? There's no actual framework/library from Apple to create a leaderboard in GameKit. You have to write one yourself from scratch. Although, using the OpenFeint library would give you all this for you, but that's if you want to use it.
More information here on a tutorial to do just what you're asking.
http://icodeblog.com/2009/10/29/iphone-coding-tutorial-creating-an-online-leaderboard-for-your-games/