Database Discussion Boards

pnpfriend24-Mar-04 4:44

24-Mar-04 4:44

Hello all.. I use CDatabase and CRecordSet to access to MS Access database
Here what I did to update some record of the table
I have database called db1 and it contains table1
table one contains three columns, data1, data2, and data3

and I have an array to insert to the table1,
I want to update data2 if data3 = true

so I wrote the following code..

<br />
CDatabase db;<br />
MyCRecordSet(&db);<br />
<br />
BOOL bSuccess = db.Open(mdsn, FALSE, FALSE, "ODBC;",FALSE);<br />
tablename = "table1";<br />
rs.Open(CRecordset::forwardOnly,tablename);	<br />
//arr is an array that contains string.<br />
for(int i=0;i<5;i++)<br />
{<br />
  CString qstr = "Update " + tablename + " set data2 = '" + arr(i) + "' where data3=1";<br />
rs.m_pDataBase->ExecuteSQL(qstr);<br />
rs.Requery();<br />
<br />
 }<br />
db.Close();<br />

but the table didnt' get updated..
why..is it?
Thank you

Re: CRecordSet and requery

kzyczynski24-Mar-04 6:23

kzyczynski

24-Mar-04 6:23

Bill Gates says Smile | :)

:
CRecordset::forwardOnly A read-only recordset with only forward scrolling

Continuous Datagrid update

JM_FL24-Mar-04 1:10

JM_FL

24-Mar-04 1:10

Hello,

I've got the problem to keep a datagrid updated, everytime
changes at the database-table(sql-server) are made.
My first idea was to do this by polling (timer) and filling a DataSet,
but it seems not the best way Frown | :-(

Does anyone have suggestions?

thanks
Jörg

Re: Continuous Datagrid update

Mike Dimmick24-Mar-04 1:58

Mike Dimmick

24-Mar-04 1:58

There's currently no way for SQL Server to tell you when an update has occurred - this feature is coming in the next version, now due next year.

For the moment, you have to poll.

Stability. What an interesting concept. -- Chris Maunder

Acess Workflow and SQL 8.0

vikramlinux23-Mar-04 18:19

vikramlinux

23-Mar-04 18:19

Hi Friends,
I have some workflows created using office 2000 on sql server 2000(default instance). Now I want to port this workflows over Office XP developer using sql server (named instance). Here I am using template for parting. While Instantiating the template it gives me follwing error dialog box

---------------------------
DCOM Server modTBAD failure
---------------------------
The wizard is unable to create an application from the template because the DCOM server modTBAD failed to successfully complete the task.
---------------------------
OK
---------------------------

Does Anybody know the problem soln?

Vikram S

OleDbAdapter.Update problem

Tristan Rhodes23-Mar-04 10:35

Tristan Rhodes

23-Mar-04 10:35

I'm trying to update an access database via the update method from a modified dataset.

I know the dataset is modified, and the DataAdapter is valid and functional.

I fill my dataset with this command in the data adapter:

"SELECT [File Extentions].*
FROM [File Extentions]"

Then, i add a number of rows via this method:

		private bool Add(string extention, Type castType)<br />
		{<br />
			//Get Table<br />
			DataTable currentTable = ds_Data.Tables["Table"];<br />
			<br />
			//Get new row for table<br />
			DataRow newRow = currentTable.NewRow();<br />
<br />
			//Fill new row<br />
			newRow["File_Extention"] = extention;<br />
			newRow["File_Type"]		 = castType;<br />
<br />
			//Add Row<br />
			currentTable.Rows.Add(newRow);<br />
<br />
			ds_Data.AcceptChanges();<br />
<br />
			//Update database<br />
			adapter.Update(currentTable);<br />
<br />
			return true;<br />
		}

The changes are reflected in the data adapter, but not in the database.

Does anyone know why this is?

Cheers

Cata

Re: OleDbAdapter.Update problem

Edbert P23-Mar-04 11:35

Edbert P

23-Mar-04 11:35

I think it is because you are calling ds_Data.AcceptChanges().
It commits all the changes made to your dataset which means the DataRowState for all rows are changed from Added to Unchanged. Therefore, your adapter.Update(currentTable) won't update your database as the data in the table is considered original/unchanged.

Just remove the ds_Data.AcceptChanges() as the adapter.Update() will automatically call this for you. As long as you set the right InsertCommand your database should be updated.

Edbert P.
Sydney, Australia.

Re: OleDbAdapter.Update problem

Tristan Rhodes24-Mar-04 11:53

Tristan Rhodes

24-Mar-04 11:53

[EDIT]:
Sorry, found out why it was spitting it out. Didn't like spaces in the table name. My mistake, thanks for the help.
[EDIT]

If i don't use AcceptChanges, it throws an OLEDBException when i try to run the update method.

Any other ideas?

I'm pretty new to DB programming, just trying to get all the n00b stuff under my belt. Smile | :)

Cata

Connectionless recordset error

Adam Gritt23-Mar-04 4:35

Adam Gritt

23-Mar-04 4:35

In trying to create a recordset I keep getting an error when I open it under C#. I would use ADO.NET, but for backwards compliance with the application it talks too, I need ADO 2.6. Below is a snippet of the code I am using. If anyone has input as to what the problem may be, please let me know.

[code]
ADODB.Recordset rs = new ADODB.Recordset;
Object obj1 = null;
Object obj2 = null;

rs.Fields.Append( "Name", adVarChar, 32, adFldMayBeNull, null );
rs.CursorLocation = adUseClient;
rs.Open( obj1, obj2, adOpenForwardOnly, adLockReadOnly, -1 );
[/code]

This code causes a COMException under C# that says: "Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another." The same code works fine under regular c++ and VB6. Does anyone have any input to this?

Re: Connectionless recordset error

Mike Dimmick24-Mar-04 2:13

Mike Dimmick

24-Mar-04 2:13

If you need to omit an optional parameter in a COM call using C#, you should use System.Reflection.Missing.Value.

ADODB.Recordset rs = new ADODB.Recordset();
 
rs.Fields.Append( 
  "Name",
  DataTypeEnum.adVarChar, 
  32,
  FieldAttributeEnum.adFldMayBeNull,
  null );
 
rs.CursorLocation = CursorLocationEnum.adUseClient;
 
rs.Open(
  Missing.Value, 
  Missing.Value, 
  CursorTypeEnum.adOpenForwardOnly, 
  LockTypeEnum.adLockReadOnly, 
  -1 );

Stability. What an interesting concept. -- Chris Maunder

Re: Connectionless recordset error

Adam Gritt24-Mar-04 3:29

Adam Gritt

24-Mar-04 3:29

Thank you very much. I am still learning the intricisies of C# and haven't looked into the System.Reflection namespace much yet. Everything works fine now. Thanks for the help.

moving in mfc recordset

kzyczynski23-Mar-04 4:04

kzyczynski

23-Mar-04 4:04

just one small question

in my prog i have an i_data value from listctrl and i want to move in recorset
to record with the same ID member, so i'm doing this:
pDoc->m_fmediaMDBSet.MoveFirst();
while (!pDoc->m_fmediaMDBSet.IsEOF()) {
if (pDoc->m_fmediaMDBSet.m_ID == i_data)
break;
pDoc->m_fmediaMDBSet.MoveNext();
}
ASSERT(pDoc->m_fmediaMDBSet.m_ID == i_data);
...
and i don't like it Unsure | :~

is there a better (and faster) way to do this job?

thanks again
Chris

Re: moving in mfc recordset

DiWa25-Mar-04 8:33

DiWa

25-Mar-04 8:33

(Beep) not enough information to proceed (Beep)

My solution to such a problem:
I keep the recordset and the list-control in sync, so that the index of the list-element is the same as the one in the recordset, ie

int nIndex;
if( -1 ==( nIndex =GetListCtrl().GetNextItem( -1, LVNI_SELECTED )))
{
return;
}
m_pSet->SetPosition( nIndex+1 );

hope it will help Smile | :)

,
dirk

Re: moving in mfc recordset

kzyczynski26-Mar-04 3:19

kzyczynski

26-Mar-04 3:19

yess (: it is what i was looking for
I was using old mfc4.1.hlp documentation and there is nothing about
CRecordset::SetAbsolutePosition(..)

thanks
Chris

I need Free SQL Server 2000 EBook

xstoneheartx22-Mar-04 23:52

xstoneheartx

22-Mar-04 23:52

Hi I need a free SQL Server 2000 E-Book
Who can help me

i fpund one but it was in chinees language.. Frown | :(

Re: I need Free SQL Server 2000 EBook

Mike Dimmick23-Mar-04 3:54

Mike Dimmick

23-Mar-04 3:54

SQL Server 2000 Books Online, updated January 2004: http://www.microsoft.com/downloads/details.aspx?FamilyID=a6f79cb1-a420-445f-8a4b-bd77a7da194b&DisplayLang=en[^]

Stability. What an interesting concept. -- Chris Maunder

Re: I need Free SQL Server 2000 EBook

Sarvesvara (BVKS) Dasa27-Mar-04 3:07

Sarvesvara (BVKS) Dasa

27-Mar-04 3:07

Thanks

I was born intelligent
Education ruined me!.

Month to date in SP

Anonymous22-Mar-04 10:26

Anonymous

22-Mar-04 10:26

I want to create a Stored procedure that looks up data based off the last full month and also one for year to date data. These SP will fire as part as a script so there can be no user input regarding the dates. Is there a way to do this?

Chris

Re: Month to date in SP

Edbert P22-Mar-04 11:27

Edbert P

22-Mar-04 11:27

Sure.
Just put a condition like below for data from the last month

WHERE MONTH(dtmTransactionDate) = MONTH(DATEADD(m, -1, GETDATE()))<br />
AND YEAR(dtmTransactionDate) = YEAR(DATEADD(m, -1, GETDATE()))

If you need to get specific date (e.g. starting from 15 of Jan to 15 of Feb) just add DAY condition to it.
For year to date, just subtract 1 year from the current date using the DATEADD function.

Edbert P.
Sydney, Australia.

Re: Month to date in SP

michanne26-Mar-04 2:58

michanne

26-Mar-04 2:58

If you are interested in the last full month and need the last day - you run into problems with February.

Try:

declare @month char(10),@lastmonth datetime

set @month = Convert(Char(6),getdate(),112)+'01'
Print @month

select @lastmonth = dateadd(m,-1,cast(@month as datetime))
print @lastmonth --First day of prior month

select @lastmonth = dateadd(d,-1,cast(@month as datetime))
print @lastmonth --Last day of prior month

Barbara

SQL For Smarties

afronaut22-Mar-04 10:00

afronaut

22-Mar-04 10:00

create table TestLoan(
loanid int identity(1,1),
custid int,
loanvalue varchar(50)
)
GO

INSERT INTO TestLoan values(2,'First Loan')
INSERT INTO TestLoan values(2,'Second Loan')
INSERT INTO TestLoan values(2,'Third Loan')
INSERT INTO TestLoan values(2,'Fourth Loan')
INSERT INTO TestLoan values(2,'Fifth Loan')

GO

Does anyone know a way I could return the 3 most recent loans in the same row? The trick would be making it always be the 3 most recent loans, no matter what else was added.

*->>Always working on my game, teach me
*->>something new.
cout << "dav1d\n";

Re: SQL For Smarties

Edbert P22-Mar-04 11:16

Edbert P

22-Mar-04 11:16

Here is one that you might be able to use:

DECLARE @TotalLoanValue varchar(150)<br />
<br />
SELECT TOP 3 @TotalLoanValue = COALESCE(@TotalLoanValue + ', ', '') + loanvalue<br />
FROM TestLoan<br />
ORDER BY loanid DESC<br />
<br />
SELECT @TotalLoanValue

This will work with SQL 2K. I haven't tested it with any other DBs.
It will return something like this:
Fifth Loan, Fourth Loan, Third Loan

I hope this helps Smile | :)

Edbert P.
Sydney, Australia.

Re: SQL For Smarties

afronaut22-Mar-04 11:42

afronaut

22-Mar-04 11:42

Wow Edbert - I'm not even sure how this works. Isn't COALESCE meant to return the first non null value? Can you explain the mechanics a bit?

*->>Always working on my game, teach me
*->>something new.
cout << "dav1d\n";

Re: SQL For Smarties

Edbert P22-Mar-04 12:08

Edbert P

22-Mar-04 12:08

Sorry, it was 9AM in the morning and I haven't had my coffee Poke tongue | ;-P

Yes, COALESCE is meant to return the first non-null value from the values passed.

Have a look at this code:
SELECT TOP 3 @TotalLoanValue = COALESCE(@TotalLoanValue + ', ', '') + loanvalue

The first time the @TotalLoanValue variable is processed, it will return NULL as the value. I use COALESCE to return empty string ('') instead, so when I concatenate the next rows, they will not result in null.
You can also use ISNULL(@TotalLoanValue + ', ', '') instead of COALESCE(@TotalLoanValue + ', ', '') as they're basically doing the same thing, except that ISNULL only accepts two values.

What the whole SQL statement does is just to concatenate the result of the query into one comma-delimited string. Just change the delimiter if you need to.

Good luck! Big Grin | :-D

PS: Use WHERE loanvalue IS NOT NULL if you want to always return 3 records.

Edbert P.
Sydney, Australia.

Re: SQL For Smarties

Bill Dean8-Apr-04 1:59

Bill Dean

8-Apr-04 1:59

Self joins! There are a beautiful thing when some Neanderthal wants a denormalized report from you nice orderly normalized data structure. WTF | :WTF:

Try this (works on sql server. Access is ???):

select top 1 * 
from 
	testloan t1,
	testloan  t2,
	testloan t3
where 
	t1.loanid<>t2.loanid and
	t2.loanid<>t3.loanid and
	t1.loanid<>t3.loanid
order by 
	t1.loanid desc,
	t2.loanid desc,
	t3.loanid desc

Bill

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