问题如下：

1、要开发一个兼容多种数据库（如ACCESS，SQL，ORACLE），看到有些用到了反射，有些用到了IF判断，想问：此种方法会不会影响到读写数据库的总执行时间？

2、还是如果关于多数据库，在三层结构中。数据访问层和中间业务层是不是要各写一个interface?然后根据不同的数据库类型然后实例化

3、在学习过程中。对数据库的操作总是读。改。删，增操作。每一个不同的操作都要写一个方法，不胜其烦。重复的地方很多（大部分只是SQL语句的不同），麻烦看下面代码？有没有什么方法还可以再精简它！！

public class NoteOperate
{
    SqlHelper Helper = new SqlHelper();
    public NoteOperate()
    {
        //
        // TODO: Add constructor logic here
        //
    }
    /// <summary>
    /// 添加留言
    /// </summary>
    /// <param name="userName"></param>
    /// <param name="postTime"></param>
    /// <param name="qq"></param>
    /// <param name="email"></param>
    /// <param name="ip"></param>
    /// <param name="agent"></param>
    /// <param name="Picture"></param>
    /// <param name="content"></param>
    /// <param name="hide"></param>
    /// <param name="auditNote"></param>
    public void InsertNote(string userName,DateTime postTime,string qq,string email,string ip,string agent,string Picture,string content,bool hide,bool auditNote)
    {
        OleDbParameter[] op ={
                                new OleDbParameter("@userName",userName),
                                new OleDbParameter("@postTime",postTime.ToString()),
                                new OleDbParameter("@qq",qq),
                                new OleDbParameter("@email",email),
                                new OleDbParameter("@ip",ip),
                                new OleDbParameter("@agent",agent),
                                new OleDbParameter("@picture",Picture),
                                new OleDbParameter("@content",content),
                                new OleDbParameter("@hide",hide),
                                new OleDbParameter("@auditNote",auditNote)
                            };
        string sqlText = "insert into NoteList(userName,postTime,qq,email,ip,agent,picture,content,hide,auditNote) values(@userName,@postTime,@qq,@email,@ip,@agent,@picture,@content,@hide,@auditNote)";
        Helper.ExecuteNonQuery(sqlText, op);
    }
    /// <summary>
    /// 根据ID审核留言
    /// </summary>
    /// <param name="id"></param>
    public void AuditNoteById(int id)
    {
        Helper.ExecuteNonQuery("update NoteList set auditNote='True' where id=" + id);
    }
    /// <summary>
    /// 根据ID删除留言
    /// </summary>
    /// <param name="id"></param>
    public void DeleteNoteById(int id)
    {
        Helper.ExecuteNonQuery("delete * from NoteList where id=" + id);
    }
    /// <summary>
    /// 根据ID回复留言
    /// </summary>
    /// <param name="id"></param>
    /// <param name="reContent"></param>
    /// <param name="reTime"></param>
    public void ReContentById(int id,string reContent,DateTime reTime)
    {
        OleDbParameter[] op ={
                                new OleDbParameter("@reContent",reContent),
                                new OleDbParameter("@reTime",reTime.ToString()),
                                 new OleDbParameter("@id",id),
                            };
        string sqlText = "update NoteList set reContent=@reContent,reTime=@reTime where id=@id";
        Helper.ExecuteNonQuery(sqlText);
    }
}