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.
Related
I have a UWP C# app and I need to connect to my SQL Server Express database.
When I connect to the database from tools option in Visual Studio, I can copy the connection string. Connectivity tests successfully, but when I try to connect with code I always get this error:
System.Data.SqlClient.SqlException: 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: TCP Provider, error: 25 - Connection string is not valid)
string connectionString =
#"Data Source=DESKTOP-IF672GA\SQLEXPRESS;Initial Catalog=TestDatabase;Integrated Security=True";
SqlConnection sc = new SqlConnection(connectionString);
sc.Open();
Enabling TPC/IP in SQL Server configuration manager helped.
Lookup UWP sandboxing as a likely cause.
I can reproduce your issue when I use Windows authentication. Could you please try to use SQL Server authentication instead of Windows authentication?
As follows:
string connectionString =#"Data Source = DESKTOP-IF672GA\SQLEXPRESS;Initial Catalog = TestDatabase;User ID=xxx;Password=xxxxx";
enable Named Pipes, and TCP/IP.
Type compmgmt.msc in the CommandLine, to Open SQL Server Configuration Manager.
Enable Named Pipes, and TCP/IP.
restart SQL service and Server Browser.
If not work, Open the Package.appxmanifest file of your UWP project in the manifest designer. In the Capabilities tab, select the Enterprise Authentication checkbox if you are using Windows Authentication for authenticating your SQL Server. and following:
privateNetworkClientServer
enterpriseAuthentication
internetClient
internetClientServer
https://learn.microsoft.com/en-us/windows/uwp/data-access/sql-server-databases#first-set-up-your-solution
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.
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?
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.
I have the following code to connect to a sql server compact edition 2008:
private SqlConnection sqlConn;
public void createConnection()
{
String connectionString = #"Data Source=C:\Projects\somefile.sdf;Persist Security Info=False";
sqlConn = new SqlConnection(connectionString);
sqlConn.Open();
}
However, I keep getting the following error when sqlConn.Open() is executed:
"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)"
Does anyone have any ideas what the problem might be? I can create a connection to the db in the database explorer but it doesn't seem to work in code.
The Sql* classes in System.Data.SqlClient can only be used to connect to a regular SQL Server instance.
To connect to a SQL CE database, you need to create a SqlCeConnection object in System.Data.SqlServerCe.dll.
Is the sdf file in the same directory as the executing application?
How to specify the location of the SDF file
Often times the .SDF database is not running in the current directory so it becomes necessary to programatically set the path to the SDF file. This is an example (.net C#) on how to do this when the SDF file is located in the same directory as the executing application.
Data Source=" + (System.IO.Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly().GetName().CodeBase) + "\\MyData.sdf;Persist Security Info=False;
Source