I am planning in creating a student information system where multiple computers can access the same server through LAN connection. The server will have a database about the students information. I pretty much have a background in creating a program similar to this but i was only able to make it for 1 computer. I don't know how to connect that database to another computer. Like for instance:
Teacher A uses Computer 1 to access the Student Information System and
Teacher B uses Computer 2 to access it as well. Any modification done
by Teacher A will be updated to the database and it will be seen as
well for Teacher B.
And my other concern is whether I should make it web-based or not. I only have an experience with using WPF Application for this kind of system but someone told me that its easier if i used a web-based instead in this kind of networking idea. Can you tell me the advantages and disadvantages of using a web-based and its counterpart.
to summarize:
How can I connect multiple computers to access a single database system.
Which is better to use if its web-based application or desktop application.
Much appreciated.
Couple of points
Set up a machine for making it a server where your database will be residing. All the machines will be pointing to this server and database using LAN.
You can create both web based and desktop based application. I would prefer to go for web based application so that in future you can extend to access this system outside the college premises.
Both Web based and desktop based application can work for you in this case. For the database you can use SQlServer2008 and share this database over the LAN so that it can be accessed from all the computers in the network.
You must create one server machine for the database which will be accessed by other client machines on your LAN.
It is quite easy you just need to give the ipaddress of sql machine in connection string instead of "." And every thing else will be same .
You will have more than one solution to make the database be used in different locations.
1- Regarding the desktop application we can setup the application on a terminal server (considering the server configurations and how many users will access the server) and the user will access the sever through the terminal service (the application will access only one database for all users in different locations.
2- The desktop application can be run in a several locations accessing a database at the same location, By using the (Database Replication) we will have an updated data in all location.
3- The application that the users access over the internet is called a (web application), it is a software that is accessed through a web browser running on client’s machine called a web application, the application will access only one database for all users.
4- Adding a (web service) to the desktop application will allows different machines to interact with each other through a network.
The question is which is the best solution?
Option (1) is the easiest one because we don't need changing anything in the application but if the internet connection is disabled no one can access the application and if a bad internet connection then we will facing many complaints from the users.
Option(2) is good because we don't need changing anything in the application as well the database server will replicate the information with each other and update the information for all locations.
I prefer option(4) when designing a new application.
I prefer option(2) when the application is old and there is no ability to modify or it will take a lot of time to modify.
Related
I have an application that has two main parts. First, the client, basicly is the user iterface, second, a repository that is a library, that connects with the database and has all the logic to insert, update, delete... and ensures the coherence of the data.
The application is not deplyed yet, and by the moment the client uses directly the repository to access to the database. But when I will have to deploy the application to be used for many users, inside the LAN, I think that this is not the best solution.
First solution
Install the client and the repository in all the computer of the users that need the application.
This have the disadvantage that when I update the application, I have to update many applications, and perhaps not all the applications are updated because of any reason. So if the update is of the repository that fix some problem, if the client that has not updated the application will introduce incoherence data in the database, if the fix is to correct this type of problem.
Second solution
The client use direcly the repository, but the application is installed in a network drive. I have only one installation, so if I need to update the application, I have to do it once.
The application is not so big, about 12MB, but it could be a bit slow because has to go through the net from the server to user computer. So perhaps some user could copy the application to the local computer, so I can't ensure that happens the problem with the first solution.
Third solution
The client application does not use the repository directly, the repository is in the server and the client use WCF to communicate with the server, and the server uses the repository to access to the database.
The disadvantage is that the server has to run the repository, so if there are many clients connected, it needs a lot of RAM, instead that if the computers of the users have the application in local, the memory is needed in the local computer.
In sumary, when I have to deply this kind of application, which is the best solution, or which is the solution that would you use in your projects?
Thank you so much.
This really depends on your deployment method, are you using a ClickOnce to deploy it? If so you could keep the data local to each PC, avoid those RAM issue, and if you send out a new update change the required version number and set it to check prior to running, that way they will be unable to run the program without updating it. The problem is they must have network access, but this would also be an issue with remote data. In this situation you would only need network access during the update, not sure if this would be an issue or not.
This isn't exactly a code question as much as it is an advice question. I currently working on a program for a small business. This program does a multitude of things from updating their local access database, edits and updates Word and Excel docs, etc. Now I have the WPF/C# based program running on a Windows 8 computer but they would like to be able to run it from multiple computers. My first instinct was to make the project again as a WPF Browser application. My questions is how would one set something like that up? Would I have to dedicate a computer with special software to handle just this program, the database, and their documents? Any Suggestions or tips would be greatly appreciated.
It doesn't have to be a WPF Browser App to run on multiple PCs. I suggest using Click Once deployment, where all users automatically get the latest version from a shared folder on an office server or just one of the other PCs in the office.
If they want all of these instances of your application to connect to a common data source or sources, then you will need one computer that hosts the server application and its database (you'll now have 2 projects: the server application, which might run as a Windows Service and have no UI, and the client application, which is the WPF app).
This computer be an existing Windows server in the office or it can even be just one of the PCs in the office, but that PC must be kept on for others to use the app and if anyone reboots it in the middle of the day others could lose some of the data they were updating.
Fundamentally, you need to alter the WPF application so that it fetches and sends its data from/to the "server," most likely using WCF services.
It is a lot to digest, but in incremental steps you can get there. The biggest hurdle will be getting your first successful WCF communication between server and client. Once you cross that threshold you'll be well on your way!
I have a question regarding C# Windows Forms connecting to external hosted databases.
I have a GoDaddy SQLServer 2008 database that I use for my web development database purposes. I am creating a C# windows form and I need that to connect to the database. I know how to connect a C# Windows Form to a local database, so I figured that the only difference would be to use a different connection string.
The connection string I am using is as follows:
Data Source=limeoatsdb.db.8996219.hostedresource.com; Initial Catalog=database; User ID=userid; Password=password;
I replaced the values above with dummy values, but obviously in my code they have the correct values.
First of all, is it even possible to connect a C# windows form to a GoDaddy database?
Secondly, if it is possible, any ideas on what I am doing wrong?
This is not possible. GoDaddy blocks all connections to its databases from systems it doesn't manage.
This is typical of many hosting companies. It's common that you can only use their databases from their own systems, for security reasons.
If you need access to your data, you'd need to create some form of intermediary step, such as building an API in your website which could be accessed by your form.
Beyond GoDaddy blocking ports, I should point out this is a bad idea if you plan on distributing the app.
If you allow clients to connect directly to your database, you're essentially leaving the front door wide open. There'd be nothing stopping me from connecting to your DB server with SQL Management Studio and fiddling with your data.
Think of it this way: in a web app, you'd never give client-side JavaScript direct access to your database. Instead, it has to go through your app server.
I'd create some kind of server that provides an API that the client Win Form can call. The server can even be a regular web server that provides REST/SOAP/whatever APIs. A good place to start might be looking in to WCF.
Yes, you can connect to a SQL Server database on GoDaddy servers.
It's a feature I've used to access the database through SQL Server Management Studio.
Check this: https://stackoverflow.com/questions/357147/go-daddy-sql-server-2005-remote-connection
Basically, when creating your database, make sure you check the "Direct Access" option.
Obviously, this is a security issue you must be aware of.
Now, i am planning to have 1 main computer and 2 client computer in the same domain. I want to run a form application in the main computer that uses Sqlite database. Then I want to query some data in the main computer from client computers. What would be your suggestions about those 2 questions of mine:
What is the best way to implement this server-client structure to communicate computers.
What is the best way to get a big datatable from main computer that uses sqlite.
I am using .Net Framework 4.0 for Form applications.
you may share the directory, either via Netbios (aka samba, for linux users) or nfs.
however, this is not a good idea, since sqlite locks the file, this may break your implementation if the filesystem fails for whatever reason. you might want to use a real distributed architecture, helping concurrency and load balancing.
another way would be to use sqlite, but proxy it through a web service, made by you specifically for this. it will serve the requests, and it would be run in the same server where you want the sqlite file, so you can avoid sharing the file/directory containing the database
You could set up a WCF service that serializes and deserializes commonly shared model/domain objects. WCF sends it across the wire.
I'm going to develop a POS system for medium scale company
and the requirement for me is to make all data on time for all of their branches
while in my mind, move the server from local to web would solve this problem
but, i never done any online server for window application
may i know what is the best option for use as secure database ?
such as SQL can handle this well ?
i tried to google but all of the result return is not what i want
may i know what will you do when you facing this problem ?
my knowledge on coding is just VB and CS
also SQL for database
i would like to learn new if there is better option
i hope it is impossible to access by anonymous and it is store secure at back-end only
What you probably want to do is create a series of services exposed on the internet and accessed by your application. All database access would be mediated by these services. For security you would probably want to build them in WCF and expose them through IIS. Then your Windows application would just call these services for most of its processing.
If you design it properly you could also have it work with a local database as well so that it could work in a disconnected manner if, for example, your servers go down.
Typically you don't move the server off of the site premises.
The problem is that they will go completely down in the event your remote server is inaccessible. Things that can cause this are internet service interruption (pretty common), remote server overloaded (common enough), basically anything that can stop the traffic between the store location and your remove server will bring them to their knees. The first time this happens they'll scream. The second time and they'll want your head due to the lost sales.
Instead, leave a sql server at each location. Set up a master sql server somewhere. Then set up a VPN connection between the stores and this central office. Finally, have the store sql boxes do merge replication with the central office. Incidentally, don't use the built in replication, but an off the shelf product which specializes in replicating sql server. The built in one can be difficult to learn.
In the event their internet connection goes dark the individual stores will still be able to function. It will also remain performant as all of the desktop app traffic is purely to the local sql box.
Solving replication errors is much easier than dealing with a flaky ISP.
I would recommend you to check Viravis Platform out.
It is an application platform that also can be used just as an online database for any .NET client with the provided SDK. It has its own generic windows and web clients and some custom web solutions for some specific applications.
You may be using it as a complete solution or as a secure online database backend.