SQL Server connection string causing error? - c#

In a Winforms application, I have a connection string that causes an error
data source=(local);initial catalog=RegisterDB;persist security info=False
Error:
An unhandled exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll
Additional information:
A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: Named
Pipes Provider, error: 40 - Could not open a connection to SQL Server)
Thanks for the help Arif Ansari but it still gives the same error.
I'm using Microsoft Visual Studio 2013 Express with SQL Server. I created the database from within Microsoft Visual Studio 2013 Express
Can anyone help?
Hi marc_s
Sorry it didnt work. I created the Database RegisterDB manually with Microsoft Visual Studio 2013 Express in server "(localdb)\v11.0"
Can anyone help ???????

Please Try it
SqlConnection con = new SqlConnection("Data Source=(local);Database=RegisterDB;Integrated Security= true");

try this query as your connection string format
Server=myServerName\myInstanceName;Database=myDataBase;User Id=myUsername;
Password=myPassword;
or this
Server=myServerAddress;Database=myDataBase;Trusted_Connection=True;
basically check the instance of the server that you are running.
Check if the instance service is running or not.
Type services.msc in the start menu to open the Services List.
Check for the name SQL SERVER (your instance name).
If the instance status is Started, issue is in your connection string or user permissions.
Else if the status is empty or stopped, start the instance and then try connecting.
you may also refer this site for connection string format.

The SQL Server that comes with Visual Studio 2013 is the 2012 Express version - and that by default install the "LocalDB" support.
So I would try this connection string instead:
"data source=(localdb)\v11.0;initial catalog=RegisterDB;Integrated Security=SSPI;"
Does that work? If not: are you auto-creating the database, or if not, did you manually create that database RegisterDB that you're referencing in the connection string?

Related

C# app with SqlClient does not work on another computer

I have written an application that uses SqlClient and a local mdf database. However, it does not work on another machine (throwing an exception that the server cannot be run) and I assume this is because there is no SQL server installed? But I thought that using local database and SqlClient elimites the need for the server, something like the old SQL CE. Is that the problem?
EDIT Exception: System.Data.SqlClient.SqlException (0x80131904): A network-related or instance-specific error occurred while extablishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections
As for connection string, I keep the one generated by Visual Studio Express, just modify the path to use the app folder.
SqlConnection s = new SqlConnection(#"Data Source = (LocalDB)\MSSQLLocalDB; AttachDbFilename ="+ System.IO.Path.GetDirectoryName(Application.ExecutablePath)+ #"\Database1.mdf; Integrated Security = True");
Is there a simple way how to rework this so that my app does not require SQL server installed? All I need is to have it use the local database file in its folder.

Connection String to SQL Server 2014 Failing

A developer friend and I could not get a connection string to work on my PC.
I'm calling to a local db instance which is Management Studio 2014 (one of the free editions).
It fails on connection.Open();
The Code is:
string conn = ConfigurationManager.ConnectionStrings["DatabaseConnection"].ToString();
IDbConnection connection = new SqlConnection(conn);
connection.Open();
App.Config is:
<connectionStrings>
<add name="DatabaseConnection"
connectionString="data source=MIKE-PC; initial catalog=dbname;integrated security =True"
providerName="System.Data.SqlClient" />
</connectionStrings>
The Error is:
An unhandled exception of type 'System.Data.SqlClient.SqlException'
occurred in System.Data.dll
Additional information:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)
There are many possible issues that you can check to correct this:
Make sure your database server is running: open run or shortcut Window + R, type services.msc, hit enter. Make sure the SQL Server (SQLEXPRESS) service is running.
Open your SQL Management Studio. Try to connect to your database from there to make sure your server name (data source) and database name (initial catalog) are correct.
Make sure your database can be accessed using Integrated Security. You can tell that it does if you can connect to your database using "Windows Authentication" from your MS SQL Server Management Studio.
Hope this help.

Connect to local sql database in c#

I'm working on C# .net application that needs to connect to a simple database. This database is btw in the same visual studio project and is called Playerdatabase.mdf.
In the application I want to connect to the database by using the following code:
string connectionString = "Data Source=(LocalDB)\v11.0;AttachDbFilename=C:\\Users\\User1\\Documents\\Visual Studio 2013\\Projects\\ProreactorTest\\ProreactorTest\\Playerdatabase.mdf;Integrated Security=True;Connect Timeout=30";
SqlConnection con = new SqlConnection(connectionString);
con.Open();
But when I try to run the application and when it calls the open() method I got the exception:
Additional information: A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL
Inner exception: can not find network path.
I looked at the path (by browsing to it) and it looks fine. I also read that disabling the firewall works, tried that but got the same exception.
Does anybody have a idea or suggestion? Any feedback is welcome!

Unable to connect to local database in Visual Studio 2012 express For Web: (error 26)(C#)(SQL Server 2012)

Recently, I've made a simple website with a database (in an App_Data folder). I made a class file (in an App_Code folder) with the following method that will create a connection to the database:
public static SqlConnection ConnectToDb(string dbFileName)
{
string path = HttpContext.Current.Server.MapPath("App_Data/");
path += dbFileName;
string connString = #"Data Source=.\SQLEXPRESS;AttachDbFilename=" +
path +
";Integrated Security=True;User Instance=True";
SqlConnection conn = new SqlConnection(connString);
return conn;
}
When I need to open that connection, I get the following message:
A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
What I don't understand is that I used the -same- method in another website that I built over a year ago in Visual Studio 2010, where it worked fine.
I checked the path and it was correct, same with the database file name in the parameters.
What is wrong with the code or with VS's settings? Thanks in advance.
EDIT: Just tried to use (localDB)\v11.0 instead of .\SQLEXPRESS
and now I get this error message:
The user instance login flag is not allowed when connecting to a user instance of SQL Server.
You're getting that error because the (localDB)\v11.0 is already a user instance of SQL Server. When you were using the SQLEXPRESS SQL Server instance, well, it's not. So, just get rid of the User Instance=true on the connection string.

error while Connecting .mdf database

I developed a small project in visual studio 2010. In my project I attach a service-based database named database1.mdf.
My connectionString is :
Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True
It works fine on my developer pc but it throws an exception on a client's pc.
Exception is :
A network-related or instance-specific error occurred while
establishing a connection to SQL Server. The server was not found or
was not accessible. Verify that the instance name is correct and that
SQL Server is configured to allow remote connections. (provider: SQL
Network Interfaces, error: 26 - Error Locating Server/Instance
Specified)
I don't understand what is happening.
Two things need to occur before you can connect to a SQL Server Express database.
SQL Server Express must be installed on the target server. Having the file present isn't sufficient. (This is what the error you're experiencing likely means).
The path to your database file should be an absolute path to rule out the possibility of a file location error.
this connection string is for your developer machine. you share your database on the network. you also must update your connection string by adding ip address of your server.

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