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Jun 23rd, 2009

Problem in Connecting to a database

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Hi all,

i am trying some code examples given in a book. I am getting an error while connecting to the database.I have installed sqlexpress edition and trying to connect to system database "master".

Below is the error 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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server)"

And here is the code which i am trying.

C# Syntax (Toggle Plain Text)
class Program
    {
        static void Main(string[] args)
        {
            // Create a connection string builder
            SqlConnectionStringBuilder csb = new SqlConnectionStringBuilder();
 
            // Define connection string attributes using three techniques
            csb.DataSource = "(local)";
            csb.Add("Initial Catalog", "master");
            csb["Integrated Security"] = true;
 
            // Output the connection string from the connection string builder
            Console.WriteLine("Connection string:\n{0}", csb.ConnectionString);
 
            // Create a connection string from the connection string builder
            SqlConnection connection = new SqlConnection(csb.ConnectionString);
            // Open and close the connection
            connection.Open();
            Console.WriteLine("\nConnectionState = {0}", connection.State);
            connection.Close();
            Console.WriteLine("ConnectionState = {0}", connection.State);
 
            Console.WriteLine("\nPress any key to continue.");
            Console.ReadKey();
        }
    }
class Program
    {
        static void Main(string[] args)
        {
            // Create a connection string builder
            SqlConnectionStringBuilder csb = new SqlConnectionStringBuilder();

            // Define connection string attributes using three techniques
            csb.DataSource = "(local)";
            csb.Add("Initial Catalog", "master");
            csb["Integrated Security"] = true;

            // Output the connection string from the connection string builder
            Console.WriteLine("Connection string:\n{0}", csb.ConnectionString);

            // Create a connection string from the connection string builder
            SqlConnection connection = new SqlConnection(csb.ConnectionString);
            // Open and close the connection
            connection.Open();
            Console.WriteLine("\nConnectionState = {0}", connection.State);
            connection.Close();
            Console.WriteLine("ConnectionState = {0}", connection.State);

            Console.WriteLine("\nPress any key to continue.");
            Console.ReadKey();
        }
    }

pls help me...

Thanks

Last edited by Ancient Dragon; Jun 24th, 2009 at 9:12 am. Reason: add code tags and removed color tags

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nmakkena

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since Dec 2008

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Jun 23rd, 2009

Re: Problem in Connecting to a database

Here is an example of connecting to an SQL Database, executing a query, and loading a DataTable:

c# Syntax (Toggle Plain Text)
    private void button1_Click(object sender, EventArgs e)
    {
      const string connStr = "Data Source=apex2006sql;Initial Catalog=Leather;Integrated Security=True;";
      const string query = "Select * From Invoice Where InvNumber = @InvNumber";
      using (DataTable dt = new DataTable())
      {
        using (SqlConnection conn = new SqlConnection(connStr))
        {
          conn.Open();
          using (SqlCommand cmd = new SqlCommand(query, conn))
          {
            cmd.Parameters.Add(new SqlParameter("@InvNumber", 1100));
            using (SqlDataReader dr = cmd.ExecuteReader())
            {
              dt.Load(dr);
            }
          }
          conn.Close();
        }
        System.Diagnostics.Debugger.Break();
      }
    }
    private void button1_Click(object sender, EventArgs e)
    {
      const string connStr = "Data Source=apex2006sql;Initial Catalog=Leather;Integrated Security=True;";
      const string query = "Select * From Invoice Where InvNumber = @InvNumber";
      using (DataTable dt = new DataTable())
      {
        using (SqlConnection conn = new SqlConnection(connStr))
        {
          conn.Open();
          using (SqlCommand cmd = new SqlCommand(query, conn))
          {
            cmd.Parameters.Add(new SqlParameter("@InvNumber", 1100));
            using (SqlDataReader dr = cmd.ExecuteReader())
            {
              dt.Load(dr);
            }
          }
          conn.Close();
        }
        System.Diagnostics.Debugger.Break();
      }
    }

By default SQL does not enable network protocols which results in the error message you are seeing. Here is the parameters to install SQL 2005 express (the password needs to be changed, i set it as p@ssw0rd):

C# Syntax (Toggle Plain Text)
"setup.exe" /qb ADDLOCAL=SQL_Engine,SQL_Data_Files,SQL_Replication,Client_Components,Connectivity,SQL_SSMSEE INSTANCENAME=SqlExpress SAVESYSDB=1 SQLBROWSERAUTOSTART=1 SQLAUTOSTART=1 AGTAUTOSTART=1 SECURITYMODE=SQL SAPWD=p@ssw0rd DISABLENETWORKPROTOCOLS=0 ERRORREPORTING=0 SQMREPORTING=0 ADDUSERASADMIN=1 INSTALLSQLDIR="%ProgramFiles%\Microsoft SQL Server\"
 
"setup.exe" /qb ADDLOCAL=SQL_Engine,SQL_Data_Files,SQL_Replication,Client_Components,Connectivity,SQL_SSMSEE INSTANCENAME=SqlExpress SAVESYSDB=1 SQLBROWSERAUTOSTART=1 SQLAUTOSTART=1 AGTAUTOSTART=1 SECURITYMODE=SQL SAPWD=p@ssw0rd DISABLENETWORKPROTOCOLS=0 ERRORREPORTING=0 SQMREPORTING=0 ADDUSERASADMIN=1 INSTALLSQLDIR="%ProgramFiles%\Microsoft SQL Server\"

SQL 2005 Express enable remote connections:
http://support.microsoft.com/kb/914277

SQL 2008 Express enable remote connections:
http://www.linglom.com/2009/03/28/en...-2008-express/

sknake

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Jun 23rd, 2009

Re: Problem in Connecting to a database

plus don't forget to check up network settings - firewalls and antivirus can do funny things

VIeditorlover

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since Dec 2007

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Jun 23rd, 2009

Re: Problem in Connecting to a database

Start SQL server instance.

adatapost

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Posting Genius

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