c#带参数数组链接数据库方法

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

namespace DAL
{
    public class SQLHelper
    {
        private static readonly string connstring = ConfigurationManager.ConnectionStrings["connString"].ToString();
        /// <summary>
        /// 执行增、删、改操作
        /// </summary>
        /// <param name="sql">要执行的sql语句</param>
        /// <param name="param">参数数组</param>
        /// <returns>返回受影响的行数</returns>
        public static int Update(string sql,SqlParameter[] param)
        {
            SqlConnection conn = new SqlConnection(connstring);
            SqlCommand com = new SqlCommand(sql,conn);
            if (param!=null)
            {
                com.Parameters.AddRange(param);
            }
            try
            {
                conn.Open();
                return com.ExecuteNonQuery();
            }
            catch (Exception ex)
            {
                string info = "执行public static int Update(string sql,SqlParameter[] param)方法出错：" + ex.Message;
                throw new Exception(info);
            }
            finally
            {
                conn.Close();
            }
        }
        /// <summary>
        /// 执行返回单一结果及的方法
        /// </summary>
        /// <param name="sql">要执行的sql语句</param>
        /// <param name="param">参数数值</param>
        /// <returns>返回单一结果</returns>
        public static object GetExecuteScalar(string sql, SqlParameter[] param)
        {
            SqlConnection conn = new SqlConnection(connstring);
            SqlCommand com = new SqlCommand(sql, conn);
            if (param!=null)    
            {
                com.Parameters.AddRange(param);
            }
            try
            {
                conn.Open();
                return com.ExecuteScalar();
            }
            catch (Exception ex)
            {
                string info = "执行 public static object GetExecuteScalar(string sql, SqlParameter[] param)方法出错：" + ex.Message;
                throw new Exception(info);
            }
            finally
            { conn.Close(); }
        }
        /// <summary>
        /// 执行返回一个结果集
        /// </summary>
        /// <param name="sql">要执行的sql语句</param>
        /// <param name="param">参数数组</param>
        /// <returns>返回一个结果集合</returns>
        public static SqlDataReader Get(string sql,SqlParameter[] param)
        {
            SqlConnection conn = new SqlConnection(connstring);
            SqlCommand com = new SqlCommand(sql, conn);
            if (param!=null)
            {
                com.Parameters.AddRange(param);
            }
            try
            {
                conn.Open();
                return com.ExecuteReader(CommandBehavior.CloseConnection);
            }
            catch (Exception ex)
            {
                string info = "执行public static SqlDataReader Get(string sql,SqlParameter[] param)方法出错" + ex.Message;
                throw new Exception(info);
            }
        }
    }
}