有个网站是分三层架构实现的，其中数据访问层是一些基础的访问数据库的类组成，这些类以前从未进行异常检测和处理，请问是否需要添加异常处理，如果需要，能写个例子给我看看,真心求教大虾们！

public class DBase
{
 public DBase(string str)
    {
        dbstr=str;
    }
    private OleDbConnection con;
    private string dbstr;
    OleDbCommand cmd;

    public void Open()
    {
        if (con == null)
        {
            string constr="Provider=Microsoft.Jet.OLEDB.4.0;Data Source="+dbstr;
            con = new OleDbConnection(constr);
        }
        if (con.State == ConnectionState.Closed)
            con.Open();
    }
    public void Close()
    {
        if (con != null)
            con.Close();
    }
    public void Dispose()
    {
        if (con != null)
        {
            con.Dispose();
        }
    }
    public OleDbParameter MakeInParam(string ParamName, OleDbType DbType, int Size, object Value)
    {
        OleDbParameter param = new OleDbParameter();
        param.ParameterName=ParamName;
        param.OleDbType=DbType;
        param.Size=Size;
        param.Value=Value;
        return param;
    }
    public int ReadCount(string Sqlstr, OleDbParameter[] Params)     
    {
        cmd = new OleDbCommand();
        cmd.Connection = con;
        foreach (OleDbParameter param in Params)
            cmd.Parameters.Add(param);
        cmd.CommandText = Sqlstr;
        OleDbDataReader rd = cmd.ExecuteReader();
        rd.Read();
        int count= rd.GetInt32(0);
        rd.Dispose();
        cmd = null;
        return count;
    }
    public OleDbDataReader CreateReader1(string Sqlstr, OleDbParameter[] Params)     
    {
        cmd = new OleDbCommand();
        cmd.Connection = con;
        foreach (OleDbParameter param in Params)
            cmd.Parameters.Add(param);
        cmd.CommandText = Sqlstr;
        OleDbDataReader rd = cmd.ExecuteReader();
        return rd;
    }
    public OleDbDataReader CreateReader2(string Sqlstr)
    {
        cmd = new OleDbCommand();
        cmd.Connection = con;
        cmd.CommandText = Sqlstr;
        OleDbDataReader rd = cmd.ExecuteReader();
        return rd;
    }
    public bool Createbool(string Sqlstr, OleDbParameter[] Params)
    {
        cmd = new OleDbCommand();
        cmd.Connection = con;
        foreach (OleDbParameter param in Params)
            cmd.Parameters.Add(param);
        cmd.CommandText = Sqlstr;
        try
        {
            OleDbDataReader rd = cmd.ExecuteReader();
            return true;
        }
        catch
        {
            return false;
        }

    }

在此基础上能加上异常处理吗？