I am New to the more enhanced features of the C# and .NET coding practices
I have been trying to Find A solution to using a particular method in C# for Winforms, Windows Services And ASP.NET web Applications where you program your connection to SQL and Convert the C# Code file to a dll to be used in your project.
The idea is to Create the Connection and Convert it to a dll so that every time you start a function and need to make a database connection you will just write it where you say
Function ABC
{
//VB Version would be like this as i have seen this
Dim DCDLL as New Dataconn
//Where 'DCDLL' is the DLL file which is being declared as a new dataconnection
//C# Version would be Alon these Lines
SQLConnection DataConn = New SQLConnection(DCDLL)
}
I have only seen the VB Code version of the Call so I am not keen on the C# Method that this would be done
Meanwhile The DLL Holds all the other code like
string ConnectionString =
"Data Source=Datasource; UID=User; PWD=Pass; Persist Security
Info=True; Initial Catalog= Catalog";
Dataconn = new SqlConnection(ConnectionString);
Dataconn.Open();
the purpose of the DLL would be to handle the connection to the database, Open it catch errors if dataconnection is not successfull and close the connection if needed so that you dont have to programatically do this every time. Also it is only responsible for the connection therefore you can use a function to call the connection execute the procedure and whatever else is required.
The idea of using a DLL is just to make the Connection settings to the Database a little more secure, the Connection obviously wont become super secure but it adds more security than having the Code in you code pages etc.
i have spoken to and seen people use this type of method but my research on how to achieve this via google and other sources does not seem to understand what i am searching for.
I am trying to understand that when i code this file how it must be done as to ensure that it handles the database connection correctly without issues and doesnt break.
If anyone can Give me Examples in C# of how to do this it would be appreciated or if you know of any pages that have explained how to achieve this i would be most grateful for your assistance
You should put your connection strings in app.config / web.config, and use c# to get the values...
Get ConnectionString from app.config in c#
You can also encrypt the connection string...
http://msdn.microsoft.com/en-us/library/89211k9b(v=vs.80).aspx
Related
Recently I am working on an .Net project. We used EF to handle SQL, when we make an installer of the program, we realize that app.config is visible which mean that the connection string is not safe.
I am looking for a way to add connection string (or maybe secret code and username) to the EF so that the connection string is not visible.
Something like change old code from this
Using db As ConnectDb.adoSentoEntities= New ConnectDb.adoSentoEntities
'TODO
End Using
to this
Using db As ConnectDb.adoSentoEntities= New ConnectDb.adoSentoEntities(ConnectionString)
'TODO
End Using
But since we used connect code to SQL all over the place, changing every single line of code is not possible. There is a way I only need to add connection string once?
You’d be better off encrypting the connection string section in the app.config. You wouldn’t need to make any changes.
Storing any sort of configuration in an assembly can be read using a hex editor.
It’s been answered on here before.
Encrypting Connection String in web.config
You’d be better off using a trusted connection if you’re using SQL Server. The user running the app would need to have permissions and no username and password is required.
Save connection string is settings of project properties.
Go in project properties.
Select settings.
Add new setting as connection string and save connection string.
Then you can use it for whole project.
I tried searching the net for this probably simple answer, but without success. I have my WPF app almost ready - using connection strings to connect to my 3 databases (EnteralDB, ParenteralDB, PatientDB) that have several tables.
Problem is that it works while debugging because I hard wired the connection string to specific location (my desktop)
using (SQLiteConnection con = new SQLiteConnection(#"Data Source= C:\Users\Peter\Desktop\EnteralDB"))
But how I can I make the connection string "universal" - meaning that it will work when I create setup for the app and it will install on a new computer? How to embed the database files into the project so they are PART of the project itself and then somehow point with the connection strings to them?
Thank you very much for help!
EDIT Actually, the comment by Clemens is correct. I changed the connection string to just the filename (EnteralDB.db), set copy if newer with content for the database properties and it is working
I just created a desktop Winforms application with localhost database.
The connect string I am using is this:
SqlConnection connect = new SqlConnection(#"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\Administrator\Desktop\learningsystem\LearningSystem\LearningSystem\LearningSystem.mdf;Integrated Security=True");
If I want to run my application on other computers, how should I make it work?
EDIT：SOLUTION
Thank for all the help! I tried the following steps. I think it is working now. But please correct me if I did something tricky.
1. add a new setting item in project property setting. App.config will automatically update:
<connectionStrings>
<add name="LearningSystem.Properties.Settings.LearningConn" connectionString="Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\LearningSystem.mdf;Integrated Security=True;Connect Timeout=30"
providerName="System.Data.SqlClient" />
</connectionStrings>
2. In my program, just add the following statement to connect to the sql server
SqlConnection connect = new SqlConnection(#"Data Source = (LocalDB)\MSSQLLocalDB; AttachDbFilename=|DataDirectory|\LearningSystem.mdf;Integrated Security = True; Connect Timeout = 30");
Further question
If others will run this application on their computer(not in the same network), they just go into the project setting and change the value by selecting the database file I provide to them,the connectionString will automatically change, right?
Thanks!
It's generally a bad idea to hard code such stuff in your application. Normally, application settings and connection strings are placed in the application's configuration file (in the ConnectionStrings section).
Just like with all strings, you could build your connectionstring from dynamic parts (variables, settings, etc.) and then pass that generated connectionstring to the SqlConnection constructor. Again, to make those separate parts configurable without hard coding them in your application, you might want to add them to your application's configuration file (in the AppSettings section). But IMHO this is an overly complex solution in most scenarios. Putting the entire connectionstring in the ConnectionStrings section is more straightforward (and more flexible).
Anyway, again, to make your application configurable, you might use your application's configuration file (App.config or Web.config), you need to add a reference to System.Configuration in your project's .NET Framework dependencies and use the AppSettings and ConnectionStrings properties of the System.Configuration.ConfigurationManager class.
(Of course, there are more ways to make your application configurable. But using the application configuration file is one of the most straightforward solutions.)
Edit:
When deploying your app to another computer, you need to copy its database over too. If you want to use the application on multiple machines and let them connect to the same database, you might want to leave LocalDB and migrate the data to a SQL Server (Express) instance and make it accessible over the (local) network.
Edit 2 (regarding the recent edits in your post):
I see in step 1 that you are using an application setting (called LearningConn) in your solution now. That's fine. However, it is important that you also use that setting in step 2, like this:
SqlConnection connect = new SqlConnection(Properties.Settings.Default.LearningConn);
If you change the setting in Visual Studio, it will update the connection string. Since the setting will probably have application scope, it will not be possible to update the setting/connection string within your application in runtime (by the user).
I'm not sure if your connection string using |DataDirectory| will always work as expected in all scenarios. I have only been using it in ASP.NET webapplications. If it does work in WinForms applications, you might read this document to learn how to set it up. But personally I am somewhat sceptical about this approach.
I personally would opt for a solution where you use a placeholder in your connection string, which you replace with the full path to the .mdf file before you pass it to your SqlConnection constructor.
When you use "{DBFILE}" as the placeholder, for example, the value of your LearningConn setting would look like this:
Data
Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename={DBFILE};Integrated
Security=True;Connect Timeout=30
(Note that this value should be a single line without any line breaks!)
You might create a separate setting in your application called DbFile (of type string) to store the actual value that should be put in place of {DBFILE} in your connection string. When you use scope "user" for that setting, the value might be changed from within the application by the user. When saved, it might not be saved directly in the application's configuration file, however, but in an additional configuration file hidden somewhere in the user's Windows user profile. You might read this document to learn more about application settings.
Your code in step 2 might eventually look something like this:
string connectString = Properties.Settings.Default.LearningConn;
string dbFile = Properties.Settings.Default.LearningSystemDb;
connectString = connectString.Replace("{DBFILE}", dbFile);
SqlConnection connect = new SqlConnection(connectString);
To let your application's users select and store the database .mdf file to use, you might include (a variation of) the following code in your application somewhere:
using (var dlg = new System.Windows.Forms.OpenFileDialog())
{
dlg.Title = "Select database file to use";
dlg.Filter = "Database Files (*.mdf)|*.mdf";
dlg.CheckFileExists = true;
if (dlg.ShowDialog() == System.Windows.Forms.DialogResult.OK)
{
Properties.Settings.Default.DbFile = dlg.FileName;
Properties.Settings.Default.Save();
}
}
Your question is not clear!
you need work with one Database on 2 or more PC?!
OR
you need work with 2 separate programs?
if you need 2 separate programs :
you must copy .mdf file to other PC at same address or keep mdf address in app.config and read it before connect to SQL.
How to Read From app.config
if you need work with one Db you must connect to dataBase Server such as SQL Server and keep connection string in app.config in connectionStrings tag.
Get connection string from App.config
If you want to work on other PCs, rather than building it dynamically make the connection string more generic:
Server=(localdb)\\mssqllocaldb;Database=LearningSystem;Trusted_Connection=True;MultipleActiveResultSets=true
This should create the mdf file under 'mssqllocaldb' in %appdata% for each user. You might need LocalDb installed (which you tick during SQL Server installation)
I am using Visual Studio 2010 and Microsoft Access 2010 to develop a desktop application using C# programming language.
connection string is:
connectionString="Provider=Microsoft.ACE.OLEDB.12.0;Data
Source=|DataDirectory|\KBank.accdb;Persist Security Info=False"
and i give it the password in the C# code as follows:
public string GetConnectionStringByName()
{
string returnValue = null;
ConnectionStringSettings settings = ConfigurationManager.ConnectionStrings["Info_Bank_Project.Properties.Settings.KBankConnectionString"];
if (settings != null)
returnValue = settings.ConnectionString + ";Jet OLEDB:Database Password=blablabla";
return returnValue;
}
i have used the database in the project in just one simple "Select" query.
so, concerning to the security issue..
can any one decrypt the access database or see the password?
and what is your suggestion to make it hard for any one to see the database data
This is little old thread, My experience on this issue might help someone.
You can create C++ DLL with the strong password located inside it, then call it from C# app to encrypt/Decrypt methods with the data base file name.
No, your data is not safe, since anyone can inspect your code using an MSIL decompiler and retrieve your connection strings from your app. There will be a point at some point in your process where someone has the possibility of seeing that password, whether it's in memory, in reflection, or something else.
If you have data that is in the possession of someone other than you, not on your servers, then you can assume you no longer have control over that data.
Now, with all that said, you can make it harder for them to get to by encrypting the database file and obfuscating your code.
Why not just put the password in your app.config and encrypt the app.config.
See here
I have three computer in a office and I have installed my C#-2005 Project on all three
computers. But Problem is that Boss wants Sql-server-2000 on One PC out of three and other
would share the same.
I don’t know how to share Sql-server-2000 between three PC?. How to do?.
Confusion:-
Thanks for your co-operation but here I have a confusion on majority people said to check
TCP/IP address and consider the Connection string as per main server from client PC.
Suppose I have financial project and there would be thousand of connection string in a
project. As per above I have to change thousand of connection string as per main pc.
Now think it is a one customer's need If I have ten cutomer having same offer than think How much time I have to waste on it?. I have to modify thousand of connection string ten time more?.
If it is true than it will take lots of time on installation to each customer.
I don’t know if it is only way?.
The Connection string I have utilized on my each winform is as below:
string connstr = "server=.;initial catalog=maa;uid=mah;pwd=mah";
SqlConnection conn = new SqlConnection(connstr);
conn.Open();
Here suggested about Config File and same I don't know if some body give me idea about how to consider it with my C#2005 project than it will save my lots time.
When you connect to the database in your code, you'll a database connection string of some sort somewhere in there. Figure out the connection string for the Database server and set your code to point to that database server's connection info; I'd bet you currently you have it pointed at localhost
If you're using SQL Server you may need to enable remote connections on the database server.
added: you may need to modify firewall settings as well to allow SQL Server traffic (thanks Jared)
.
Edit: For putting the configuration string into a central location.
Your posted code
string connstr = "server=.;initial catalog=maa;uid=mah;pwd=mah";
SqlConnection conn = new SqlConnection(connstr);
conn.Open();
Change to
Assuming your application has a App.Config file then you'd add an entry in there like
<add key="DBConnectionString" value="server=.;initial catalog=maa;uid=mah;pwd=mah"/>
And change your C# code to be like
string connstr = ConfigurationManager.AppSettings["DBConnectionString"];
SqlConnection conn = new SqlConnection(connstr);
conn.Open();
Putting the ConfigManager call into a class might be a good idea if you have a lot of settings to retrieve and/or believe the configuration storage methodology might change down the road. Going with the above example is WAY better than having the string literal scattered throughout your code.
Enable theTCP/IP connection in SQL Server. So that you can connect remotely from any pc within the network
check here
If your problem is that you embedded your connection string in the code, then you are going to have to do some refactoring. These would be the general steps, you will have to tailor them a bit to your situation.
Add your connection string to the app.config file.
Create a static/shared method that will read the connection string from the
config file.
Do a find and replace in your solution to replace all
of the hard coded connection strings in your code with the (class
and) name of the method that gets the connection string.
This is probably going to be easier than rewriting all of your data calls to use something like enterprise library or EF.
You will need to do as the others suggested, such as changing the connection string and enabling TCP/IP within SQL Server, but you will also likely need to configure your firewall to allow requests to SQL Server (default port of 1433) through.