c#链接数据库问题

Question

想做登录界面可是不知道怎么弄
        private bool readDataBase()
        {
            OleDbConnection conn = new OleDbConnection(
          "Provider=Microsoft.Jet.OLEDB.4.0;" +
          "Data Source=d:\\db1.mdb");
            conn.Open();
            OleDbCommand command = conn.CreateCommand();
            command.CommandText =
                "SELECT * FROM tableuser " +
                "where name = " + textBox1.Text;
            OleDbDataReader dataReader = command.ExecuteReader();
            dataReader.Read();
            if (dataReader["pword"].ToString() == textBox2.Text)
            {
                return true;
            }
            return false;        }

Answer 1

using(OleDbConnection conn = new OleDbConnection(""))
{
  conn.Open();
  OleDbCommand command = conn.CreateCommand("SELECT * FROM tableuser where [name] = '" + textBox1.Text+"'",conn);
  OleDbDataReader dataReader = command.ExecuteReader(CommandBehavior.CloseConnection);
  if(dataReader.Read())
  {
  }
}

Answer 2

 static string connectionstring = "server=.;database=db_CSManage;uid=sa;pwd=as;";
            /// <summary>
            /// 执行T-SQL语句
            /// </summary>
            /// <param name="sql">T-SQL(update,delete,insert)</param>
            /// <returns></returns>
            public static int ExecuteNoQuery(string sql)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlCommand cmd = new SqlCommand(sql, con);
                try
                {
                    con.Open();
                    int i = cmd.ExecuteNonQuery();
                    return i;                }
                catch (SqlException ex)
                {
                    throw ex;                }
            }
            /// <summary>
            /// 执行T-SQL返回DataSet
            /// </summary>
            /// <param name="sql">T-SQL语句</param>
            /// <returns></returns>
            public static DataSet ExecuteNoQueryDataSet(string sql)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlDataAdapter sda = new SqlDataAdapter(sql, con);
                try
                {
                    DataSet ds = new DataSet();
                    sda.Fill(ds);
                    return ds;
                }
                catch (SqlException ex)
                {
                    throw ex;
                }
            }
            /// <summary>
            /// 执行T-SQL返回DataSet
            /// </summary>
            /// <param name="sql">T-SQL or Porc</param>
            /// <param name="cmdtype">命令类型</param>
            /// <param name="commandpara">参数</param>
            /// <returns>DataSet</returns>
            public static DataSet ExecuteNoQueryDataSet(string sql, CommandType cmdtype, SqlParameter[] commandpara)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlDataAdapter sda = new SqlDataAdapter(sql, con);
                if (commandpara != null)
                {
                    paramadd(sda.SelectCommand, cmdtype, commandpara);
                }
                try
                {
                    DataSet ds = new DataSet();
                    sda.Fill(ds);
                    return ds;                }
                catch (SqlException ex)
                {
                    throw ex;                }            }            /// <summary>
            /// 执行带参数,命令类型T-SQL
            /// </summary>
            /// <param name="sql">T-SQL</param>
            /// <param name="cmdtype">命令类型</param>
            /// <param name="commandpara">参数</param>
            /// <returns></returns>
            public static int ExecuteNoQuerypara(string sql, CommandType cmdtype, SqlParameter[] commandpara)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlCommand cmd = new SqlCommand(sql, con);
                paramadd(cmd, cmdtype, commandpara);
                try
                {
                    con.Open();
                    int i = cmd.ExecuteNonQuery();
                    return i;                }
                catch (SqlException ex)
                {
                    throw ex;                }            }            /// <summary>
            /// 执行T-SQL语句
            /// 返回第一行第一列
            /// </summary>
            /// <param name="sql">T-SQL</param>
            /// <returns></returns>
            public static int ExecuteScalar(string sql)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlCommand cmd = new SqlCommand(sql, con);
                int scalar = 0;
                try
                {
                    con.Open();
                    object obj = cmd.ExecuteScalar();
                    if (obj != null)
                    {
                        scalar = Convert.ToInt16(obj);
                    }
                    return scalar;                }
                catch (SqlException ex)
                {
                    throw ex;                }
            }
            /// <summary>
            /// 执行T-SQL语句
            /// 返回第一行第一列
            /// </summary>
            /// <param name="sql">t-sql语句</param>
            /// <param name="cmdtype">Command命令类型</param>
            /// <param name="commandpara"></param>
            /// <returns></returns>
            public static string ExecuteScalar(string sql, CommandType cmdtype, SqlParameter[] commandpara)
            {
                SqlConnection con = new SqlConnection(connectionstring);
                SqlCommand cmd = new SqlCommand(sql, con);
                string scalar = "";
                if (commandpara != null)
                {
                    paramadd(cmd, cmdtype, commandpara);                }
                try
                {
                    con.Open();
                    object obj = cmd.ExecuteScalar();
                    if (obj != null)
                    {
                        scalar = obj.ToString();
                    }
                    return scalar;                }
                catch (SqlException ex)
                {
                    throw ex;                }
            }
            private static void paramadd(SqlCommand cmd, CommandType cmdtype, SqlParameter[] commandpara)
            {
                cmd.CommandType = cmdtype;
                foreach (SqlParameter sqlpara in commandpara)
                {
                    cmd.Parameters.Add(sqlpara);
                }            }