[odb-users] help！ I want to query some line(20 rows) from a table, how to do it ?

[qgjie]

I have define tow object:  one is "line" , the other is "FixedLine".

class       Line
{
public:
    Line() {}
    friend  class   odb::access;


    long                    Line_Id;
    char                    Line_Title[PLATFORM_NAME_STRLEN];
    string                  Line_SubTxt;
    int                     Line_Price;
    int                     Line_VipPrice;

    ptime                   create_Time;
    ptime                   destroy_Time;

    shared_ptr<Manage_Admin>    admin;
    shared_ptr<base_PicClass>   pics;
    shared_ptr<Line_Town>       towns;
};
class       FixedLine : public Line
{
public:
    FixedLine(int price, int vipprice):Line() {}

private:
    FixedLine() {}
    friend  class   odb::access;
    int         type;
};

Now, I want to query 20 rows from the object FixedLine


How can I implementation?

I known the SQL like this "select type from FixedLine  limit 0, 20", but ODB ?
USE VIEW ?
thanks!