初识三层架构(2)

                        }
                    }
                    return cmd.ExecuteNonQuery();
                }
            }
        }
        /// <summary>
        /// 执行非查询语句
        /// </summary>
        /// <param name="sql">SQL语句</param>
        /// <param name="parameters">传入变量</param>
        /// <returns>返回查询结果中的第一行第一列的值</returns>
        public static object ExecuteScalar(string sql, params SqlParameter[] parameters)
        {
            using (SqlConnection con = new SqlConnection(conStr))
            {
                con.Open();
                using (SqlCommand cmd = con.CreateCommand())
                {
                    cmd.CommandText = sql;
                    if (parameters != null)
                    {
                        foreach (SqlParameter param in parameters)
                        {
                            cmd.Parameters.Add(param);
                        }
                    }