Re: DAO/ADO/ODBC - C / C++ / MFC Discussion Boards

Re: DAO/ADO/ODBC

Jonathan [Darka]2-Aug-06 21:21

Jonathan [Darka]

2-Aug-06 21:21

Tara14 wrote:
Is ADO faster than DAO?

Not when dealing with JET databases, if your database code is limited to working with JET then DAO is much faster than ADO, you should use ADO if you are a VB developer or if your are a C++ developer and don't mind slow database access.

What you should be using is OLEDB.

regards,

Darka [Xanya]

"When you're taught to love everyone, to love your enemies, then what value does that place on love?"

Re: DAO/ADO/ODBC

Tara142-Aug-06 21:29

Tara14

2-Aug-06 21:29

My work is mostly related to small to medium database. That would be about 100 records with about hundred fields. I use Jet database for all my work. Is that good enough? Or should I be using something else?

Fortitudine Vincimus!

Re: DAO/ADO/ODBC

Jonathan [Darka]2-Aug-06 21:31

Jonathan [Darka]

2-Aug-06 21:31

Tara14 wrote:
Is that good enough

It should be ok, I would just stick with Jet and DAO if you have to use a Microsoft Access database.

Darka [Xanya]

"When you're taught to love everyone, to love your enemies, then what value does that place on love?"

Re: DAO/ADO/ODBC

Tara142-Aug-06 21:50

Tara14

2-Aug-06 21:50

Thanks.

Fortitudine Vincimus!

Re: DAO/ADO/ODBC

Viorel.2-Aug-06 21:26

Viorel.

2-Aug-06 21:26

Besides switching from DAO, I think you can try to improve the speed by disabling redraw operations:

myListCtrl.SetRedraw(FALSE);

// add items
. . .

myListCtrl.SetRedraw(TRUE);

If you know the number of items to be added, you can call SetItemCount before.

Additionally, you can investigate the "virtual list" concept.

For some information see http://www.pocketpcdn.com/articles/list_view.html[^].

I hope this helps.

Re: DAO/ADO/ODBC

Tara142-Aug-06 21:32

Tara14

2-Aug-06 21:32

Viorel. wrote:
If you know the number of items to be added, you can call SetItemCount before.

I did that, but it did not help much.

Viorel. wrote:
Additionally, you can investigate the "virtual list" concept.

I did search for virtual lists, but from what I gathered, it looked like one cannot do many things with virtual lists - for example: sorting cannot be done.

Fortitudine Vincimus!

Re: DAO/ADO/ODBC [modified]

Phil.Benson3-Aug-06 0:05

Phil.Benson

3-Aug-06 0:05

Tara14 wrote:
I did search for virtual lists, but from what I gathered, it looked like one cannot do many things with virtual lists - for example: sorting cannot be done.

This is not true. If you create a virtual list, you must handle the displaying of the data, and you can also handle the column click, call the requery function of the table and then invalidate the list control.

For example: Override the listviews column click virtual method...

void YourListControlView::OnColumnClick(NMHDR* pNMHDR, LRESULT* pResult){

if(NULL == pYourTable){
return;
}

*pResult = 1;
LPNMLISTVIEW pNMLV = reinterpret_cast<LPNMLISTVIEW>(pNMHDR);
ASSERT(pNMLV);

CString _sOrderBy;
CString _sOrder;
CString _sFieldName;
CDaoFieldInfo info;
ZeroMemory(&info, sizeof(CDaoFieldInfo));

m_bSortAscending = (m_nSortColumn != pNMLV->iSubItem) ? true : !m_bSortAscending;
m_nSortColumn = pNMLV->iSubItem;

if(m_bSortAscending){
_sOrder = _T(" ASC");
}
else{
_sOrder = _T(" DESC");
}

try{
pYourTable->GetFieldInfo(nSortColumn, info);
_sFieldName = info.m_strName;

_sOrderBy.Format(_T("%s %s"), _sFieldName, _sOrder);

// Requery the table
// *****************
pYourTable->m_strSort = _sOrderBy;
pYourTable->m_strFilter = _T(""); // You may need to change this !!
pYourTable->Requery();
pYourTable->MoveFirst();
}
catch(CDaoException* px_e){
#ifdef _DEBUG
px_e->ReportError();
#endif
px_e->Delete();
}

// Invalidate the list control so
// that it will be refreshed
// ******************************
GetListCtrl().Invalidate();

....

}

This assumes that your table class is derived from CDaoRecordSet. I use my own classes for DAO access, and any of the main functions (Requery, Movexx etc are capsled)

In this example, I have two member variablesto keep track of the current column and the order of sorting (m_nSortColumn, m_bSortAscending)

Also, using GetListCtrl().SetItemCountEx(nNumberOfRecordsPresnet) will speed up the displaying of the data.

Hope this helps a bit
mfg
Phil

Who the f*** is General Failure, and why is he reading my harddisk?

-- modified at 6:06 Thursday 3rd August, 2006

Re: DAO/ADO/ODBC

Tara143-Aug-06 1:54

Tara14

3-Aug-06 1:54

Thank you. I shall try it out.

Usually what I do is read data from the database and fill the list.

void CXBudget::AddPayeeList2()
{
CDBcreate *p = new CDBcreate; // this is the class I have make to handle creating a database, adding tables, adding fields, getting value as double etc ...
	CDaoDatabase *pdB=new CDaoDatabase();
	pdB->Open(path,FALSE,FALSE,pwd);
	CString TabNam = curTableName;
	sql = ("SELECT * FROM "+TabNam+" WHERE param='budget' ORDER BY cat,payee");

	CDaoRecordset *rs;
	rs = new CDaoRecordset(pdB);
	rs->Open(AFX_DAO_USE_DEFAULT_TYPE,sql,NULL);
	CString strCategory, strPayee;
	CString strTp;
	int nFeldCount;
	nCol = 2; ;
	int nRow = 0;
	CString strRowTotal;
	
	m_XBudgetLIST_Main.DeleteAllItems(); // main list
	m_XBudgetLIST_RowTotal.DeleteAllItems();// list on the side of main list to display row total values

	nFeldCount = p->getFieldCount(pdB,strBudgetName);
	while (!rs->IsEOF()) // looping through all the rows of the database
	{
		strCategory = p->GetAsString(rs,1);
		m_XBudgetLIST_Main.InsertItem(nRow,strCategory);
		strPayee = p->GetAsString(rs,2);
		m_XBudgetLIST_Main.SetItemText(nRow,1,strPayee);
		for ( int i = 3;i<nFeldCount;i++)// looping through the columns
		{
			strTp = pCol->SetValue(p->GetAsDouble(rs,i));
			m_XBudgetLIST_Main.SetItemText(nRow,nCol,strTp);
		
			nCol++;
		}
		nCol = 2;
		strRowTotal = pCol->SetValue(Payee_RowTotal(strCategory,strPayee));
		m_XBudgetLIST_RowTotal.InsertItem(nRow,strRowTotal);
		rs->MoveNext();
		nRow++;
	}
	
	pdB->Close();
	rs->Close();
   	delete p;
	delete pdB;
	delete rs;

When the number of colunms are too many, the time for the loop to be fully executed is looong.

Fortitudine Vincimus!

Re: DAO/ADO/ODBC

Phil.Benson3-Aug-06 2:17

Phil.Benson

3-Aug-06 2:17

I would consider the following:

Both lists should be virtual, this means that you must provide the information to be displayed as needed by the list control. There are lots of tuts on Code Project regarding virtual lists.

When you load the information from the DB, set the number of rows for each list useing the method I described in my last post. Keep a member variable of the DB, and an index of the current record, as an absolute value. When the list wnats to display a specific row, it will request the item value to be displayed, i.e. row 0, subitem 0, 1, 2, 3, etc. This you can do on the fly, reading the row from the DB, getting the corresponding sub item (field) and displaying it. I know this may seem slow, but it works a treat, as only the information that is to be ACTUALLY DISPLAYED is required.

As for your secondary list that is to display information, I would suggest that you create a query def using the information provided from the main table...

mfg

Phil

Who the f*** is General Failure, and why is he reading my harddisk?

Re: DAO/ADO/ODBC

Tara143-Aug-06 22:19

Tara14

3-Aug-06 22:19

Thanks a lot. So very kind of you to explain in such detail.

I shall change my program to use virtual lists. I am begining to understand them quite well now. I have been running away from it all this while. Lets see if I end up falling in love with virtual lists.

I shall let you know what happens.

Thanks again.

Fortitudine Vincimus!

Re: DAO/ADO/ODBC

Tara142-Aug-06 21:48

Tara14

2-Aug-06 21:48

I just now added SetRedraw to my lists. They are loading significanly faster now.

Thanks a lot.

Fortitudine Vincimus!

get date from COleDateTime

Sam_the_xalan2-Aug-06 20:21

Sam_the_xalan

2-Aug-06 20:21

Hai frens,

I need to get only the date info. Need to set time to 0.

// Get the current date.
COleDateTime DateValidTill = COleDateTime::GetCurrentTime();

Wud like to get a better solution than the following.

DateValidTill.SetDateTime( DateValidTill.GetYear(),DateValidTill.GetMonth(),DateValidTill.GetDay(),0, 0, 0 );

Re: get date from COleDateTime

Steve Echols2-Aug-06 21:12

Steve Echols

2-Aug-06 21:12

Try:

COleDateTime DateValidTill = COleDateTime::GetCurrentTime();
DateValidTill.SetTime(0, 0, 0);

- S
50 cups of coffee and you know it's on!

File does not open

Ratish Philip2-Aug-06 19:52

Ratish Philip

2-Aug-06 19:52

I have an application which reads a file of particular extension, say, *.abc.
When I run the application and invoke the CFileDialog to select a file of this extension, it opens the file correctly.
Similarly, Dragging and Dropping the file to the application also works fine.
But when I right-click on the .abc file and select Open With... and select my application.exe, the application comes up but it does not open the file.

How should I accomplish this?

Cutebug

Re: File does not open

Christian Graus2-Aug-06 19:58

Christian Graus

2-Aug-06 19:58

Your application need to accept the file path as a parameter when it's run, so typing "yourapp.exe file.abc" on the command line should open the image.

Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog

Re: File does not open

toxcct2-Aug-06 20:45

toxcct

2-Aug-06 20:45

the CFileDialog class doesn't open the file for you. it only provides you an interface (dialogBox) to pick the files you want to open, bu it only returns the absolute paths of these files. only then, when your application gets those files, it has the choice to actually opening them or not.

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: File does not open

Sarath C2-Aug-06 21:22

Sarath C

2-Aug-06 21:22

Process your command line arguments.

SaRath.

"Where I am from, there is no plan B. So, take advantage of today becuase tomorrow is not promised. - 50 Cent"

My Blog | Understanding State Pattern

Question: @ DavidCrow about NetUserGetInfo()

Programm3r2-Aug-06 19:50

Programm3r

2-Aug-06 19:50

Well the function returns:

If the function succeeds, the return value is NERR_Success.
If the function fails, the return value can be one of the following error codes.
- ERROR_ACCESS_DENIED The user does not have access to the requested information.
- NERR_InvalidComputer The computer name is invalid.
- NERR_UserNotFound The user name could not be found.

So the thing is I hard code the username and the servername is NULL (servername is NULL, the local computer is used.)

But still the function is not equal to NERR_Success, thus it returns a false.

For example:
============

LPWSTR domaincontroller = NULL;

NET_API_STATUS nStatus;
WCHAR *uni_username = NULL;
uni_username =L"richardb"

nStatus = NetUserGetInfo(domaincontroller, uni_username, 3, (LPBYTE*)&buffer);

if(nStatus != NERR_Success){
retval = NULL;
return false;
}else{
return true;
}
}
===========
I have no idea what could be wrong. WTF | :WTF:

David could you plz help or know of a site or something ... anything

Thanx

Regards

Programm3r

Re: Question: @ DavidCrow about NetUserGetInfo()

Hamid_RT2-Aug-06 20:28

Hamid_RT

2-Aug-06 20:28

<br />
...<br />
...<br />
  GetUserName(lpuser, &dword);<br />
  USES_CONVERSION;<br />
nStatus = NetUserGetInfo(NULL/*local computer*/, A2W(lpuser), 3, (LPBYTE*)&buffer);<br />
then nStatus =0<br />

WhiteSky

Re: Question: @ DavidCrow about NetUserGetInfo()

Programm3r2-Aug-06 20:39

Programm3r

2-Aug-06 20:39

WhiteSky .... you lost me .. WTF | :WTF:

Regards

Programm3r

Re: Question: @ DavidCrow about NetUserGetInfo()

ThatsAlok2-Aug-06 22:03

ThatsAlok

2-Aug-06 22:03

Programm3r wrote:
eSky .... you lost me ..

offcourse

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
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Re: Question: @ DavidCrow about NetUserGetInfo()

toxcct2-Aug-06 20:43

toxcct

2-Aug-06 20:43

Programm3r wrote:
Question: @ DavidCrow

why don't you ask this on the thread you began earlier on the subject ?
why do you want only DavidCrow to answer you ?
why do you think forums are mad for ?

Suspicious | :suss:

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: Question: @ DavidCrow about NetUserGetInfo()

Programm3r2-Aug-06 20:49

Programm3r

2-Aug-06 20:49

why don't you ask this on the thread you began earlier on the subject ?
- Well first of all, I have no idea.....
why do you want only DavidCrow to answer you ?
- The question wasn't just indended for him, he was the one how answer the
question, and thus the reason his name appears.
why do you think forums are mad for ?
- ??? mad ???

Thanx for your comments

Regards

Programm3r

Re: Question: @ DavidCrow about NetUserGetInfo()

toxcct2-Aug-06 20:55

toxcct

2-Aug-06 20:55

Programm3r wrote:
why do you think forums are mad for ?
- ??? mad ???

made

TOXCCT >>> GEII power

[VisualCalc 3.0 updated ][Flags Beginner's Guide new! ]

Re: Question: @ DavidCrow about NetUserGetInfo()

Programm3r2-Aug-06 20:58

Programm3r

2-Aug-06 20:58

Besides all that .... do you perhaps have a solotion to my problem?

Regards

Programm3r

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.