再次请问：VC6+ADO+ACCESS删除大于一个月的数据

再次请教：VC6+ADO+ACCESS删除大于一个月的数据。
数据库SLGO.MDB中 表名：bill, ID:20111010164032(存储的是年月日时分秒）通过这个ID的时间和当前时间比较，大于一个月的都删掉，数据库中只保留一个月的数据。

再增加新数据前判断，下面代码是加入新的数据。

贴一段我的代码：

void CDrugProjectPage::OnBtnNext() 
{

CString strSql;
CTciApp* pApp = (CTciApp*)AfxGetApp();


m_strBillID1=m_nPersonNo;


//判断单据号是否重复
strSql.Format(_T("SELECT * FROM bill where id = '%s'"),m_strBillID1);
HRESULT hr = pApp->m_pRecordset->Open(strSql.AllocSysString(),
pApp->m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
if(!SUCCEEDED(hr))
{
AfxMessageBox(_T("打开bill表出错"));
return;
}


if(!pApp->m_pRecordset->adoEOF)
{
AfxMessageBox(_T("已经存在该单据编号的记录"));
pApp->m_pRecordset->Close();
return;
}

pApp->m_pRecordset->Close();

//新增一条记录
strSql = _T("SELECT * FROM bill");
hr = pApp->m_pRecordset->Open(strSql.AllocSysString(),
pApp->m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
if(!SUCCEEDED(hr))
{
AfxMessageBox(_T("打开bill表出错"));
return;
///
}



try
{
CString str;

pApp->m_pRecordset->MoveFirst();


pApp->m_pRecordset->AddNew();

pApp->m_pRecordset->PutCollect("id",_variant_t(m_strBillID1));
pApp->m_pRecordset->PutCollect("type",_variant_t(m_nSectionNo));
str = m_tTime.Format(_T("%Y-%m-%d"));
pApp->m_pRecordset->PutCollect("time",_variant_t(str));
// pApp->m_pRecordset->PutCollect("name",_variant_t(m_nPersonName));


pApp->m_pRecordset->PutCollect("height",_variant_t(tci_person_height));
pApp->m_pRecordset->PutCollect("weight",_variant_t(tci_person_weight));
pApp->m_pRecordset->PutCollect("age",_variant_t(tci_person_age));
if(tci_person_sex==0)
pApp->m_pRecordset->PutCollect("sex",_variant_t(_T("男")));
else
pApp->m_pRecordset->PutCollect("sex",_variant_t(_T("女")));


for(int i=0;i<3;i++)
{
CRunChannel* prunChan1 = g_pRunTci->GetRunChannel(i);
const StTciRunParam* pRunParam1 = prunChan1->GetRunParam();
const StTciRunParam* m_pRunParam=g_pRunTci->GetRunChannel(0)->GetRunParam();
const DrugInfo* pDI1 = g_pDrugInfo->GetDrugInfo(pRunParam1->iDrugNameID);
const KineticInfo* pKI1 = g_pDrugInfo->GetKineticInfo(pRunParam1->iDrugNameID, pRunParam1->iKineticID);

switch(i)
{
case 0:
{
pApp->m_pRecordset->PutCollect("FirstChnlmode",_variant_t(g_szV_Mode[pRunParam1->iMode]));
pApp->m_pRecordset->PutCollect("FirstChnldrug",_variant_t(pDI1->szName));
pApp->m_pRecordset->PutCollect("FirstChnlmodel",_variant_t(pKI1->szName));
pApp->m_pRecordset->PutCollect("FirstChnlconc",_variant_t(pRunParam1->tci_syringe_drug_conc));
pApp->m_pRecordset->PutCollect("FirstChnltarget",_variant_t(m_pRunParam->tci_conc_SP));
}break;
case 1:
{
pApp->m_pRecordset->PutCollect("SecondChnlmode",_variant_t(g_szV_Mode[pRunParam1->iMode]));
pApp->m_pRecordset->PutCollect("SecondChnldrug",_variant_t(pDI1->szName));
pApp->m_pRecordset->PutCollect("SecondChnlmodel",_variant_t(pKI1->szName));
pApp->m_pRecordset->PutCollect("SecondChnlconc",_variant_t(pRunParam1->tci_syringe_drug_conc));
pApp->m_pRecordset->PutCollect("SecondChnltarget",_variant_t(m_pRunParam->tci_conc_SP));