vc6 access sql

1.select
sql="select * from Group_Operator WHERE GroupName = '"+str_GroupName+"'";
        sql="select * from GroupList";

2.update
sql.Format("UPDATE %s SET SendDelayTime = '" "%d" "' WHERE id = %d ","AlarmList",i,i_ID);
sql.Format("UPDATE %s SET CountDown = '" "%d" "' WHERE id = %d ","AlarmList",i_CountDownSet,i_ID);
sql.Format("UPDATE AlarmList SET ID = '" "%d" "' WHERE TagName = '" "%s" "' ",i,str_TagName);
3.时间查询

void CSearchDlg::OnButton1() 
{

	CMDIFrameWnd *pFrame =  (CMDIFrameWnd*)AfxGetApp()->m_pMainWnd;//主框架指针
	CMDIChildWnd *pChild =  (CMDIChildWnd *) pFrame->GetActiveFrame();//子框架指针
	CMyListView *pView = (CMyListView *) pChild->GetActiveView();//listview视
	CListCtrl *p=&pView->GetListCtrl();

	UpdateData(TRUE);
	CTime time;
	CString stry,strm,strd,date1,date2;
	CString strhour,strmin,strsec,time1,time2;

	m_date1.GetTime(time);
	stry.Format("%d",time.GetYear());
	strm.Format("%d",time.GetMonth());
	strd.Format("%d",time.GetDay());
	date1=stry+"-"+strm+"-"+strd;
	TRACE("date1=%s",date1);

	m_date2.GetTime(time);
	stry.Format("%d",time.GetYear());
	strm.Format("%d",time.GetMonth());
	strd.Format("%d",time.GetDay());
	date2=stry+"-"+strm+"-"+strd;
	TRACE("date2=%s",date2);

	m_time1.GetTime(time);
	strhour.Format("%d",time.GetHour());
	strmin.Format("%d",time.GetMinute());
	strsec.Format("%d",time.GetSecond());
	time1=" "+strhour+":"+strmin+":"+strsec;
	TRACE("time1=%s",time1);

	m_time2.GetTime(time);
	strhour.Format("%d",time.GetHour());
	strmin.Format("%d",time.GetMinute());
	strsec.Format("%d",time.GetSecond());
	time2=" "+strhour+":"+strmin+":"+strsec;
	TRACE("time2=%s",time2);

	CString str_combo1,str_combo2;
	m_combo1.GetWindowText(str_combo1);
	m_combo2.GetWindowText(str_combo2);

	try{
		CString sql;

		//在aceess的时间字段设置为时间类型，具体的可以是日期比如2012-01-1，可以是时间比如17:44:02，也可以是两者的组合比如2012-01-1 17:44:02
		//然后再vc中加入的时候想acces的表的时间字段中写的时候就需要按照这个格式写入字符串。
		//sql查询的时候需要用#代表查询的是时间
		//sql="SELECT * FROM my_table WHERE my_date>=#2012-01-1# and my_date<=#2012-01-10#";//不用变量查询
		//sql.Format("select*from my_table where my_date>=#" "%s" "# and my_date<= #" "%s" "# ",date1,date2);//format形式只查询日期
		//sql="select*from my_table where my_date>=#"+date1+"# and my_date<=#"+date2+"#";//只查询日期
		//sql="select*from History where SendTime>=#"+date1+time1+"# and SendTime<=#"+date2+time2+"#";
		if (str_combo1=="GroupList")
		{
			sql="select*from History where SendTime>=#"+date1+time1+"# and SendTime<=#"+date2+time2+"#";
			if (str_combo2!="all")
			{
			sql+=" and GroupName = '"+str_combo2+"'";
			}
		}
		else if (str_combo1=="AlarmList")
		{
			sql="select*from History where SendTime>=#"+date1+time1+"# and SendTime<=#"+date2+time2+"#";
			if (str_combo2!="all")
			{
				sql+=" and TagName = '"+str_combo2+"'";
			}
		}
		else if (str_combo1=="OperatorList")
		{
			sql="select*from History where SendTime>=#"+date1+time1+"# and SendTime<=#"+date2+time2+"#";
			if (str_combo2!="all")
			{
				sql+=" and OperatorName = '"+str_combo2+"'";
			}
		}

TRACE("sql=%s",sql);
		pView->display_table(m_pConnection,m_pRecordset,"AlarmList",p,sql);

	}
	catch(_com_error e)
	{
		AfxMessageBox(e.Description());
	}

}

4.delete
        sql="delete  from Group_Operator WHERE OperatorName = '"+str_Operator_In_Group+"'";
        sql+=" and GroupName ='"+str_combo1+"'";
使用字符串变量的地方需要用单引号标记起来，如 '"+var+" '

5.
直接访问
        str_temp=(char*)(_bstr_t)m_pRecordset->GetCollect("GroupName");
使用变量CString str_field="GroupName";
        str_temp=(char*)(_bstr_t)m_pRecordset->GetCollect(_variant_t(CString(str_field)));

索引变量
                str=(char*)(_bstr_t)pRecordset->GetCollect(_variant_t(long(ii)));
6.
                    sql="SELECT   COUNT   (*)   AS   counts   FROM   AlarmList";    
                    m_pRecordset_2 = m_pConnection->Execute((_bstr_t)sql,NULL,adCmdText);
                    int i_count=m_pRecordset_2-> GetCollect("counts").intVal; //取得记录的总数目
                    TRACE("%d",i_count);