opening a connection to a database...

[bords]

can you please explain the lines in opening a connection to a database?where will i base the datasource, the initial catalog, uid.....?

[avirag]

Basically that is shows connection string of your application with your database.........

[sknake]

What type of database connection are you using? The connection strings vary by driver. Here is some english variable names associated with the connection string file names:

public static string BuildSqlNativeConnStr(string server, string database)
    {
      return string.Format("Data Source={0};Initial Catalog={1};Integrated Security=True;", server, database);
    }
    public static string BuildSqlNativeConnStr(string server, string database, string username, string password)
    {
      return string.Format("Data Source={0};Initial Catalog={1};Integrated Security=False;User Id={2};Password={3};", 
        server, 
        database,
        username,
        password);
    }
    public static string BuildExcelConnectionString(string Filename, bool FirstRowContainsHeaders)
    {
      return string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source='{0}';Extended Properties=\"Excel 8.0;HDR={1};\"",
                          Filename.Replace("'", "''"),
                          FirstRowContainsHeaders ? "Yes" : "No");
    }
    public static string BuildExcel2007ConnectionString(string Filename, bool FirstRowContainsHeaders)
    {
      return string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source={0};Extended Properties=\"Excel 12.0;HDR={1}\";",
                            Filename.Replace("'", "''"),
                            FirstRowContainsHeaders ? "Yes" : "No");
    }
    public static string BuildAccessConnectionString(string Filename, string Username, string Password, string DatabasePassword)
    {
      return string.Format("Provider=Microsoft.Jet.OLEDB.4.0;Data Source='{0}';User Id={1};Password={2};Jet OLEDB:Database Password={3};",
                                   Filename.Replace("'", "''"),
                                   Username,
                                   Password,
                                   DatabasePassword);
    }
    public static string BuildAccess2007ConnectionString(string Filename, string DatabasePassword)
    {
      return string.Format("Provider=Microsoft.ACE.OLEDB.12.0;Data Source='{0}';Persist Security Info=False;Jet OLEDB:Database Password={1};",
                                 Filename.Replace("'", "''"),
                                 DatabasePassword);
    }
    public static string BuildODBCConnectionString(string DSN)
    {
      return string.Format("DSN={0}", DSN);
    }

[pmatah]

Here is a good place to start; please scroll down the page for explainations of each property.
http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqlconnection.connectionstring(VS.71).aspx