Re: Add Column to Access database using OleDB - C# Discussion Boards

How do I read the Identity Column using ADO.NET

derik_konark26-Dec-03 4:24

26-Dec-03 4:24

Need some help :
When I tried to read Identity column with ADO.NET DataReader, I'm getting the following error::=>
"The data value could not be converted for reasons other than sign mismatch or data overflow.For example, the data was corrupted in the data store but the row was still retrievable."..

The Code which I wrote is described below:
oDR is data reader
while(oDR.Read())
{ListItem oItem = new ListItem(oDR.GetString(2),oDR.GetInt32(0).ToString());
wsdrpdwnlst1.Items.Add(oItem);} //wsdrpdwnlst1 is a list box
Note : (where oDR.GetInt32(0) supposed to give me the identity column.) but I am getting the above error. I need the help at the earliest if possible.
Cry | :((

Re: How do I read the Identity Column using ADO.NET

LongRange.Shooter30-Dec-03 10:01

LongRange.Shooter

30-Dec-03 10:01

The error is definitely pointing at your oDR.GetInt32(0).ToString() portion of your code. You don't show what the SQL select statement looks like. But it sounds like the data you are getting is either not Int32 (and thus cannot convert it) or IS CORRUPT.

The first thing to do is find out just what the problem is with the data. Put a breakpoint at the while statement, step into the read, then do a QuickWatch on the oDR object to see what your second parameter data actually is. It could be something as simple as the fact that the data IS numeric, but your database is returning leading SPACES instead of leading ZERO.

If the data looks like crap, then the next thing to do is take the SQL that you are using in your program and run it inside Query Analyzer if is SQL or the equivalent if it is Oracle. See what you get back with the raw SQL and make sure your SELECT statement is truly executing the way you think it is.

All Debug 101 tasks.

_____________________________________________
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Not because of those that do evil,
but because of those who look on and do nothing.}

ProvideProperty Attribute Problem

Takeru Koushirou26-Dec-03 2:22

Takeru Koushirou

26-Dec-03 2:22

Heyas,

I am writing on a component which uses the ProvideProperty Attribute to add new properties to other existing components. And it works fine. But, the new property doesn't have any description etc., in other words no Description, Editor etc. Attribute to make it fine. I am searching for hours now but didn't find any way to add Attributes to ProvideProperty-added properties Cry | :((

.

Does anyone have experience in this?

Thanks,
'Mike

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Re: ProvideProperty Attribute Problem

Alex Korchemniy26-Dec-03 7:29

Alex Korchemniy

26-Dec-03 7:29

Maybe you are looking too hard. Take a look at this :

http://www.codeproject.com/dotnet/iextenderprovider.asp

All you have to do is this :

[Description("Description")]
[Category("Appearance")]
public string GetMyString(Panel p)
{
return EnsurePropertiesExists(p).MyString;
}

You set the description attribute not in the class, but on the actual GetXXXX function.

Re: ProvideProperty Attribute Problem

Takeru Koushirou26-Dec-03 8:07

Takeru Koushirou

26-Dec-03 8:07

Ah, thanks very much!
This works. I already tried same as in the given code, but using the SetXXX method... well wrong choice >.<
Now it works perfect Big Grin | :-D

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Add Column to Access database using OleDB

Wouter Van Ranst26-Dec-03 1:32

Wouter Van Ranst

26-Dec-03 1:32

Hi guys,

I've been searching for this for 4 hours, but it just doens't seem to work.

I have an access database, and i have to add a column to it.

Here's my code:

string connString = "Provider=Microsoft.Jet.OLEDB.4.0;" +<br />
	@"Data Source=D:\My Documents\Visual Studio 2003.NET\VerboServe\Verboserve.mdb;" +<br />
	"User ID=Admin;" +<br />
	"Password=";<br />
OleDbConnection conn = new OleDbConnection(connString);<br />
DataSet ds = new DataSet();<br />
<br />
conn.Open();<br />
<br />
OleDbDataAdapter dataAdapter = new OleDbDataAdapter("SELECT * FROM Verbs", conn);<br />
OleDbCommandBuilder commandBuilder = new OleDbCommandBuilder(dataAdapter);<br />
<br />
dataAdapter.Fill(ds, "Verbs");<br />
<br />
ds.Tables["Verbs"].Columns.Add("Wouter");<br />
<br />
foreach (DataRow thisRow in ds.Tables["Verbs"].Rows)<br />
{<br />
	thisRow["Wouter"] = "True";<br />
}<br />
<br />
commandBuilder.QuotePrefix = "[";<br />
commandBuilder.QuoteSuffix = "]";<br />
<br />
ds.AcceptChanges();<br />
dataAdapter.Update(ds, "Verbs");

Can anyone tell me how to do this?

Thanks,

Wouter

Re: Add Column to Access database using OleDB

Heath Stewart27-Dec-03 5:09

Heath Stewart

27-Dec-03 5:09

ds.AcceptChanges is marking all rows as normal. DataAdapter.Update searches for changed rows and updates them, then internally calls AcceptChanges. Since you're doing this yourself BEFORE calling Update, the Update method is NOT seeing any changes.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
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-----END GEEK CODE BLOCK-----

Re: Add Column to Access database using OleDB

Wouter Van Ranst27-Dec-03 6:56

Wouter Van Ranst

27-Dec-03 6:56

Thankx for the info, but i am adding columns here, or is that the same?

Re: Add Column to Access database using OleDB

Heath Stewart27-Dec-03 7:01

Heath Stewart

27-Dec-03 7:01

You can't do it that way. You either have to issue an ALTER TABLE command or use a product-specific library to modify the database structure, like DDL for Access or SQL-DMO or SQL Server. This has been addressed many times before here. I suggest you click Search Comments and see some of the replies for more details and other ideas. While searching comments, you should probably also include the ADO.NET forum, too.

Re: Add Column to Access database using OleDB

Wouter Van Ranst27-Dec-03 7:23

Wouter Van Ranst

27-Dec-03 7:23

Thanks,

I'll do that

Socket Program>?????

h_wing25-Dec-03 22:45

h_wing

25-Dec-03 22:45

i'm make Socket program
this is Receive file this img file, avi file..
but can't Receive XMLfiles

this is source
* Receive File info
================================================================
while(rData!=null)
{
byte[] rbuffer = new Byte[1024];
int rcount = rData.Receive(rbuffer, rbuffer.Length, 0);
string Cm = ed.GetString(rbuffer);
Cm = Cm.Substring(0, rcount);
Cml = null;
Cml = Cm.Split(':');
this.listBox1.Items.Add("Header Info");
this.listBox1.Items.Add("Data Type : " + Cml[0]);
this.listBox1.Items.Add("Data Name : " + Cml[1]);
this.listBox1.Items.Add("Data Length : " + Cml[2]);
if (Cml[0] == "Binnary")
{ FileReceive(rData, Cml);}
else if (Cml[0] == "Str")
{this.listBox1.Items.Add("String Value :" + Cml[3]);}
rData.Close();
rData = null;}
===================================================================
* Receive file
================================================================
FileStream fout = new FileStream(@"c:\youngTemp\" + cml[1]+"1",FileMode.Create, FileAccess.Write);
NetworkStream nfs = new NetworkStream(rData);
long DataSize = int.Parse(cml[2]);
long rby = 0;
try
{
while(rby < DataSize)
{ byte[] buffer = new Byte[1024]; int i = nfs.Read(buffer, 0, buffer.Length); fout.Write(buffer, 0, i); rby += 1;
}
this.listBox1.Items.Add("Success ");}catch(Exception ex)
{
this.listBox1.Items.Add("Error");
this.listBox1.Items.Add("Error is : " + ex.ToString());}
finally{
fout.Close();nfs.Close();
nfs= null;fout = null;}
=====================================================================

Re: Socket Program>?????

Heath Stewart27-Dec-03 5:07

Heath Stewart

27-Dec-03 5:07

You should debug your code. An XML file is no different than a image file or an AVI - they are all just a stream of bytes. If your app treats them as such (And your code indicates that you do), then your app doesn't care - at the time of transfer - what is in the files themselves. XML files are not these special files sent from God, but just a formatted document, formatted accordingly to certain "guidelines" just like the various image codecs and AVI codecs.

The only problem I can see if your code is that you're writing out a binary file. Depending on how bytes are written or transfered, you may need to take file encodings into account. The only difference between the XML files you mention and the image and AVI files is that the former is a text file (ASCII, UTF8, Unicode, etc.) while the latter two are binary. There many be a problem in the way you handle text files. You should consider what FTP does, which is send such files using a text encoding while transfering.

simple generic add,mod,delete

gotohellthen25-Dec-03 21:59

gotohellthen

25-Dec-03 21:59

how to build a generic application which will take a table as a parameter
& do add,modify, delete operations on that table can some one offer a solution please !

Dileepa

Re: simple generic add,mod,delete

Heath Stewart27-Dec-03 5:02

Heath Stewart

27-Dec-03 5:02

You can't take a table as a parameter. You could take a table name or a filename with a DataTable (serialized as XML) in it. Then use commands in the System.Data namespace (like System.Data.SqlClient.SqlCommand or System.Data.SqlClient.SqlDataAdapter) to do what you need. All the documentation is in the .NET SDK documentation and there are plenty of examples here on the CP site.

detect connection

heba_zien25-Dec-03 12:05

heba_zien

25-Dec-03 12:05

hi i am making a program that controlling connecting to net, and ineed to detect connections which connected outside my program, i want to detect any connection on pc to find duration i didn,t find the way

Printing Page Number

Mazdak25-Dec-03 9:07

Mazdak

25-Dec-03 9:07

How can I set page number in printing progress? Any property or trick?

Mazy

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Re: Printing Page Number

Heath Stewart27-Dec-03 5:00

Heath Stewart

27-Dec-03 5:00

Handle the PrintDocument.PrintPage event and increment your printed page counter from 1 with each callback to your event handler.

Re: Printing Page Number

Mazdak27-Dec-03 8:50

Mazdak

27-Dec-03 8:50

Thanks Heath. Is that possible to find out number of page before printing?

Mazy

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Re: Printing Page Number

Heath Stewart27-Dec-03 11:20

Heath Stewart

27-Dec-03 11:20

That depends on you - it's your code generating and printing pages after all. If you're simply printing text, you can get the height of the font, factor in the extra line height (which you control) and margins, and measure the string to print. From that you could calculate the number of pages. If you're drawing pictures and what-not, you calculate the picture size multiplied by any zoom amounts (percentages).

Re: Printing Page Number

Mazdak27-Dec-03 19:35

Mazdak

27-Dec-03 19:35

Thanks Heath. I got the point. Smile | :)

Mazy

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Clicking through transparent windows

Anonymous25-Dec-03 5:06

Anonymous

25-Dec-03 5:06

I have a 50% transparent window that is on top of the desktop.

I want the user to be able to click 'Through the transparent window' onto objects behind it ... my computer.

The transparent window does not need force it just needs to be ontop of all the other windows.

another example is .. if you press alt-ctrl-del to bring up task manager how can i program the window to pass mouse clicks on it to the window behined it, if task manger is my program?

I hope this is clear enough to answer Smile | :)

Re: Clicking through transparent windows

Takeru Koushirou26-Dec-03 8:12

Takeru Koushirou

26-Dec-03 8:12

Maybe it would help to enumerate the visible windows, find the window laying under your window but top of all other windows and the click point lies in it's client area and pass WM_* event message to the window...
Maybe there is another easier way to do that, but maybe this will help. Good luck ^^

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multi-thread multicast server

GTR3425-Dec-03 1:19

GTR34

25-Dec-03 1:19

is it possible to write a multi-thread multicast server?
that mean one server can have many multicast group and serve different client?
any reference website about it??
thanks a lot!

Re: multi-thread multicast server

Heath Stewart27-Dec-03 4:56

Heath Stewart

27-Dec-03 4:56

Sure, why not? You can make a program do practically anything you want. Search CP for examples, or google the net with appropriate keywords. Mostly, if you use the same multicast port for the different threads handling different clients, send some sort of identifier (client name/version, etc.) so the proper thread can process it and others can drop it.

Calling function in a C# dll from C++ code

Member 78143724-Dec-03 17:05

Member 781437

24-Dec-03 17:05

Is it possible to call functions in a C# dll from C++ code? If so, what do I set in the build properties of the C# dll to create the .lib the C++ code needs?

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