MFC中关于修改access数据库数据出现的问题

CString strDBFile=_T(".\\fruit.mdb");
CString strConnect;
strConnect.Format(_T("ODBC;DRIVER={MICROSOFT ACCESS DRIVER (*.mdb)};UID=sa;PWD=;DBQ=%s"), strDBFile);
if(m_db.Open(NULL, FALSE, FALSE, strConnect))
{
m_buy.m_pDatabase=&m_db;
m_buy.Open(AFX_DB_USE_DEFAULT_TYPE, "SELECT * FROM buy where id>0");
m_buy.MoveFirst();

m_buy.m_NUM=m_INNUM1;
m_buy.m_INPRICE=m_IN1;
m_buy.MoveNext();
m_buy.m_NUM=m_INNUM2;
m_buy.m_INPRICE=m_IN2;
m_buy.MoveNext();
m_buy.m_NUM=m_INNUM3;
m_buy.m_INPRICE=m_IN3;

m_buy.Update();
UpdateData(0);
m_buy.Close();
m_db.Close();
}然后运行的时候说更新或删除的企图失败了~~~~~~~~~~~~~~~~~~~~
buy 是表明，关联m_buy

不会~