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.
Related
I am using I am using Visual Studio 2017. I just created a brand new mdf file in my project (Right click on App Data -> Add New Item -> SQL Server Database) and I called the file TestDatabase.mdf
Now I am trying to connect to it via a connection string:
<add name="TestConnection" connectionString="Server=.\SQLExpress;AttachDbFilename=|DataDirectory|TestDatabase.mdf;Database=TestDatabase; Trusted_Connection=Yes;" providerName="System.Data.SqlClient" />
Next I created a Model and then Created a EntityFramework Controller, but now when I goto the controller index method I get this error:
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 am I doing wrong?
Make sure you testDatabase.mdf available in App_Data folder.
<connectionStrings>
<add name="ConnectionName"
connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|DatabaseName.mdf;Integrated Security=True;User Instance=True"
providerName="System.Data.SqlClient" />
</connectionStrings>
This connection string that you have written is incorrect.
<add name="TestConnection" connectionString="Server=.\SQLExpress;AttachDbFilename=|DataDirectory|TestDatabase.mdf;Database=TestDatabase; Trusted_Connection=Yes;" providerName="System.Data.SqlClient" />
I assume that you have SQL Express installed in your system. This will provide a local instance of SQL to run on your machine.
As you said you are using Visual Studio 2017, you can follow these steps to get the correct connection string
Open Server Explorer
Right Click on your Database and click Properties
A property window will open, copy the ConnectionString and make sure it looks like this:
<add name="YourDbName" connectionString="Data Source=YourComputerName\SQLEXPRESS;Initial Catalog=YourDbName;Integrated Security=True" />
And now talking about this:
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)
You are getting this error because it is not getting the instance name to connect to the database. In my example, SQLEXPRESS serves as an instance name. If you don't have SQLEXPRESS you can download it from here:
https://www.microsoft.com/en-in/sql-server/sql-server-editions-express
You can follow the prompt and install this package in your system.
Once you install this, your instance will get activated. Connect your Db once again.I am sure it will work.
In case, if this error comes again, you can follow these steps:
Hit Windows + R and type services.msc and hit OK
From the given lists, search for SqlServer (SQLEXPRESS) and click start the service. This will activate your instance once again and your database is now ready to connect to your application.
Hope this helps.
Although I can connect to the server when I'm using either legacy SqlConnection or Sql Management Studio, I'm not able to make connection to Sql Server via Entity framework. In addition I've check all following things:
Data Source or Server Name or IP address is correct. it is: SKI-PC\
I'm sure that my instance name is correct.
Remote connections are allowed and also there is no firewall.
The error I'm facing 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)
Just for clarifying, my connection string in app.config is:
<add name="MyEntities" connectionString="metadata=res://*/DataModel.csdl|res://*/DataModel.ssdl|res://*/DataModel.msl;provider=System.Data.SqlClient;provider connection string="data source=SKI-PC\SEP;initial catalog=Restaurant;user id=sa;password=;MultipleActiveResultSets=True;App=EntityFramework"" providerName="System.Data.EntityClient" />
here is the connection string
<add name="Tapo_ModelContainer" connectionString="metadata=res://*/filename.csdl|res://*/filename.ssdl|res://*/filename.msl;provider=System.Data.SqlClient;provider connection string='Data Source=(LocalDB)\MSSQLLocalDB;Initial Catalog=APTapo;Integrated Security=True;MultipleActiveResultSets=True;Application Name=EntityFramework'" providerName="System.Data.SqlClient" />
The Exception
System.Data.EntityException {"The underlying provider failed on Open."}
inner Exception
"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)"
inner exception
"The system cannot find the file specified"
If i use the normal SqlConnection class, i can connect to the database.
It could be because of the permissions.
in the Authentication section. If you can not write the correct connection string you can use Connect To Database option in Tools menu item and if Test Connection is ok then copy the connection string.
I have created a login application using ASP.NET and SQL Server. It runs perfectly on my localhost but as soon as I uploaded it on GODADDY, I got the ERROR regarding the connection string.
I have also changed the connection string with the one provided by GODADDY but it did not work.
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).
Exception Details: 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: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified)
I have made DLL and BLL namespaces to which i gave reference of my asp.net application.
I have used connection string in two files (1) in DLL/clsdll.cs file (2) in web.config file as follows
Connection String in clsdll.cs file :-
con = new SqlConnection("Data Source=XXXX;Integrated Security=False;User ID=ZZZZZ;Password=YYYYY;Initial Catalog=demo1;Connect Timeout=15;Encrypt=False;Packet Size=4096");
Connection String in WEB.CONFIG file :-
<connectionStrings>
<add name="SampleConnectionString"
connectionString="Data Source=XXXX;Integrated Security=SSIP;User ID=ZZZZZ;Password=YYYYY;Initial Catalog=demo1;Connect Timeout=15;Encrypt=False;Packet Size=4096"/>
</connectionStrings>
The connection string above is the one provided by GODADDY but it doesn't work.
Can anyone help me out with this please....
only this much info is required you can remove the rest and try once
data source=XXXX;user id=XXXX; password=XXXX; initial catalog=XXXX;
Well, in your web.config, you have both the "Integrated Security" (with a spelling typo - it should be Integrated Security=SSPI) as well as an explicit username/password.
Don't do that - either you use integrated security (unlikely, in a hosted environment), or then you use user ID=.../Password=... - but don't enable BOTH at the same time!
In your case, I would try
<connectionStrings>
<add name="SampleConnectionString"
connectionString="Data Source=XXXX;Initial Catalog=demo1;User ID=ZZZZZ;Password=YYYYY;"/>
</connectionStrings>
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?