Microsoft KB Archive/313295

= How to use the server name parameter in a connection string to specify the client network library =

Article ID: 313295

Article Last Modified on 11/30/2005

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APPLIES TO


 * Microsoft SQL Server 2000 Standard Edition
 * Microsoft SQL Server 2000 64-bit Edition
 * Microsoft Data Access Components 2.6
 * Microsoft Data Access Components 2.6 Service Pack 1
 * Microsoft Data Access Components 2.6 Service Pack 2
 * Microsoft Data Access Components 2.7
 * Microsoft SQL Server 2005 Standard Edition
 * Microsoft SQL Server 2005 Express Edition
 * Microsoft SQL Server 2005 Developer Edition
 * Microsoft SQL Server 2005 Enterprise Edition
 * Microsoft SQL Server 2005 Workgroup Edition

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This article was previously published under Q313295



IN THIS TASK
SUMMARY Code Sample
 * Use the Code Sample with Various Network Libraries

REFERENCES



SUMMARY
This article describes how to programmatically specify the client network library in the connection string when you connect to a SQL Server database.

In Microsoft Data Access Components (MDAC) 2.6 and later, you can specify the client access library by using the  parameter in connection string. Therefore, you can specify a specific client access library when you are prompted by an application for a server name to which to connect. This behavior can be very useful when you are testing and troubleshooting connectivity issues for SQL Server.

For example, you can use the Osql command-line utility to connect to SQL Server and to force it to use the TCP/IP network library: osql -Stcp:myServer,portNumber -E back to the top

Code Sample
The following Microsoft Visual C# .NET code sample demonstrates how to set the connection string. The connection string has the same format irrespective of the language that you use: using System; using System.Data; using System.Data.SqlClient;

namespace getCurrentProtocol {   ///     /// Main Application Driver Class ///    class Driver {       static void Main(string[] args) {           string sCxn = &quot;server=myServer;Integrated Security=SSPI; database=master&quot;; //string sCxn = &quot;server=np:myServer;Integrated Security=SSPI; database=master&quot;; //string sCxn = &quot;server=tcp:myServer;Integrated Security=SSPI; database=master&quot;; //string sCxn = &quot;server=rpc:myServer;Integrated Security=SSPI; database=master&quot;; //string sCxn = &quot;server=lpc:myServer;Integrated Security=SSPI; database=master&quot;; string sCmd = &quot;SELECT net_library from sysprocesses where spid=@@spid&quot;; SqlConnection cxn = new SqlConnection(sCxn); SqlCommand sqlCmd = new SqlCommand(sCmd, cxn); SqlDataAdapter sqlDa = new SqlDataAdapter(sCmd, cxn); DataTable dt = new DataTable; try {               sqlDa.Fill(dt); Console.WriteLine(&quot;Hit ENTER to continue ...&quot;); Console.ReadLine; foreach (DataRow dr in dt.Rows) Console.WriteLine(dr[&quot;net_library&quot;]); }            catch (SqlException e)            { Console.WriteLine(e.StackTrace); Console.WriteLine(&quot;SQL Error Number: &quot; + e.Number); Console.WriteLine(&quot;SQL Error Message: &quot; + e.Message); }       }    } } Note the connection string and particularly the value of the server parameter: string sCxn = &quot;server=myServer;Integrated Security=SSPI; database=northwind&quot; back to the top

Use the Code Sample with Various Network Libraries
The following code samples demonstrate how to use the value of the server parameter to specify various network libraries:   TCP/IP:

server=tcp:hostname You can optionally specify a specific port number. By default, the port is 1433. server=tcp:hostname, portNumber   Named Pipes:

server=np:hostname You can optionally specify a specific named pipe.

server=np:\\hostname\pipe\pipeName By default, the pipe name is sql\query. If you connect to a named instance, the pipe name is typically in the following format:

MSSQL$instnaceName\sql\query

  Multiprotocol:

server=rpc:hostname You can optionally specify the underlying protocol.

server=rpc:hostname, protocol The default value of the underlying protocol is determined by the operating system settings where a protocol can have any one of the following values:

  Shared Memory: server=lpc:hostname   NWlink IPX/SPX: server=spx:hostname   Banyan VINES: server=vines:hostname   Apple Talk: server=adsp:hostname </li></ul>

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