asp.net有关数据库连接问题

    public class SqlDBHelper
    {
        //在配置文件Web.Config中获取连接字符串
        public static string connectionStr = ConfigurationManager.ConnectionStrings["connectionStr"].ConnectionString;

        /// <summary>
        /// 执行增删改T-SQL语句，返回执行成功与否
        /// </summary>
        /// <param name="strSql">T-SQL语句或存储过程名称</param>
        /// <param name="cmdType">T-SQL语句类别</param>
        /// <param name="param">参数列表</param>
        /// <returns>返回值为：true/false</returns>
        public static bool DoExecuteNonQuery(string strSql, CommandType cmdType, params SqlParameter[] param)
        {
            using (SqlConnection con = new SqlConnection(connectionStr))
            {
                try
                {
                    con.Open();
                    SqlCommand com = new SqlCommand(strSql, con);
                     = cmdType;
                    if (param.Length > 0)
                        com.Parameters.AddRange(param);

                    int flag = com.ExecuteNonQuery();
                    return flag > 0 ? true : false;
                }
                catch(Exception ex)
                {
                    throw new Exception("SQL Connection Faile,Bring Error DoExecuteNonQuery : "+ex.Message);
                }
                finally
                {
                    con.Close();
                }
            }
        }
}