第一次连接SQL2005数据库，很简单的

class Program

    {

        static void Main(string[] args)

        {

            string strCon = "Data Source=PC-201011141515\\SQLEXPRESS;User ID=sa;password=5447763;database=MYFIRSTDB";

            SqlConnection cmd;

            cmd = new SqlConnection(strCon);

            try

            {

                cmd.Open();

                Console.WriteLine("成功");

                cmd.Close();

            }

            catch(Exception e)

            {

                string strerror=e.ToString();

                Console.WriteLine(e.ToString());

                using(StreamWriter sw=new StreamWriter(@"G:\C#\exception.txt"))

                {

                    sw.Write(e.ToString());

                    sw.Close();

                }

                

            }

            Console.ReadKey();

        }

    }

System.Data.SqlClient.SqlException: 无法打开登录所请求的数据库 "MYFIRSTDB"。登录失败。

用户 'sa' 登录失败。

   在 System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)

   在 System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)

   在 System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)

   在 System.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)

   在 System.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(SqlConnection owningObject, SqlConnectionString connectionOptions, String newPassword, Boolean redirectedUserInstance)

   在 System.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, Object providerInfo, String newPassword, SqlConnection owningObject, Boolean redirectedUserInstance)

   在 System.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection)

   在 System.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnection owningConnection, DbConnectionPool pool, DbConnectionOptions options)

   在 System.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject)

   在 System.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject)

   在 System.Data.ProviderBase.DbConnectionPool.GetConnection(DbConnection owningObject)

   在 System.Data.ProviderBase.DbConnectionFactory.GetConnection(DbConnection owningConnection)

   在 System.Data.ProviderBase.DbConnectionClosed.OpenConnection(DbConnection outerConnection, DbConnectionFactory connectionFactory)

   在 System.Data.SqlClient.SqlConnection.Open()

   在 ConsoleApplication1sql.Program.Main(String[] args) 位置 d:\我的文档\Visual Studio 2005\Projects\ConsoleApplication1sql\ConsoleApplication1sql\Program.cs:行号 19