带参数的sql语句

1.SQLServer

 private static SqlConnection conn = new SqlConnection("server=(local);Integrated Security=SSPI;database=JSFguanliDB;");
        private static SqlDataAdapter da;
        private static SqlCommand cmd;
        /// <summary>
        /// 登陆操作
        /// </summary>
        /// <param name="userName">用户名</param>
        /// <param name="passWord">密码</param>
        /// <returns>是否成功</returns>
        static public bool UserLogin(string userName, string passWord)
        {
            cmd = new SqlCommand("select yonghuming, yonghumima from denglubiao where yonghuming=@username and yonghumima=@passwd ", conn);
            SqlParameter param = cmd.Parameters.Add("@username", SqlDbType.NVarChar, 50);
            param.Value = userName;
            param = cmd.Parameters.Add("@passwd", SqlDbType.NVarChar, 50);
            param.Value = passWord;

            conn.Open();
            SqlDataReader rdr = cmd.ExecuteReader();

            bool login = false;

            try
            {
                if (rdr.HasRows)
                    login = true;
            }
            catch
            {
                login = false;
            }
            finally
            {
                conn.Close();
            }
            return login;

        }

2.Access

  private static OleDbConnection conn = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0; " +
  "Data Source=JSFguanliDB.mdb");
        private static OleDbDataAdapter da;
        private static OleDbCommand cmd;
        /// <summary>
        /// 登陆操作
        /// </summary>
        /// <param name="userName">用户名</param>
        /// <param name="passWord">密码</param>
        /// <returns>是否成功</returns>
        static public bool UserLogin(string userName, string passWord)
        {
            cmd = new OleDbCommand("select yonghuming, yonghumima from denglubiao where yonghuming=@username and yonghumima=@passwd ", conn);
            OleDbParameter param = cmd.Parameters.Add("@username", OleDbType.VarChar, 50);
            param.Value = userName;
            param = cmd.Parameters.Add("@passwd", OleDbType.VarChar, 50);
            param.Value = passWord;

            conn.Open();
            OleDbDataReader rdr = cmd.ExecuteReader();

            bool login = false;

            try
            {
                if (rdr.HasRows)
                    login = true;
            }
            catch
            {
                login = false;
            }
            finally
            {
                conn.Close();
            }
            return login;

        }