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hi evreyone
is it possible to use xml file as database ?
if yes, is someone has any sample code in C# that can do Insert,Update and Delete job's ?
thank's alot for any help
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Yes you can. But it doesnt mean you should. Performance wise its even a worse idea.
To do insert/update/delete you will need to load the xml document, find the node that you want as parent (for insert) or the node you want to update/delete, perform the action you need to do and then save the document again.
Loading the document once and keeping it in memory will speed up the process if its small amounts of data, else you'll find yourself running out of memory soon.
Hope this helps.
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thank's for the quick anser
by database is very very small and i think,
that it will be better to use xml insted access or sql server
can i get any sample ?
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As Guffa has said, its easy to load the data in a datatable and then save it as xml. That will increase query performance. That will however increase your xml document size.
If you dont want to use that way, heres a really simplified example of an update to a xml file:
<?xml version="1.0"?>
<Employees>
<Employee>
<ID>1</ID>
<FirstName>John</FirstName>
<LastName>Doe</LastName>
</Employee>
<Employee>
<ID>2</ID>
<FirstName>Peter</FirstName>
<LastName>Pan</LastName>
</Employee>
</Employees>
string xmlFilePath = @"C:\Employees.xml";
int EmployeeIdToUpdate = 2;
string NewEmployeeLastName = "Panne";
System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
doc.Load(xmlFilePath);
System.Xml.XmlNode eNode = doc.SelectSingleNode("Employees");
for (int i = 0; i < eNode.ChildNodes.Count; i++)
{
System.Xml.XmlNode employeeNode = eNode.ChildNodes[i];
int ID = int.Parse(employeeNode.SelectSingleNode("ID").InnerText);
if (ID == EmployeeIdToUpdate)
{
//Perform action
employeeNode.SelectSingleNode("LastName").InnerText = NewEmployeeLastName;
}
}
doc.Save(xmlFilePath);
Hope this helps.
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You can save and load a DataTable as xml. Load the DataTable, change the DataRow items, and then save it.
Despite everything, the person most likely to be fooling you next is yourself.
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good.....
can i get code sample ?
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.NET has many XML manipulation classes available. Use any of them to load and save data to XML file. If you are looking for file system based database, consider SQL lite[^]
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Just use a borderless form.
xacc.ide - now with TabsToSpaces support IronScheme - 1.0 beta 1 - coming soon ((lambda (x) `((lambda (x) ,x) ',x)) '`((lambda (x) ,x) ',x))
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OK... but how do i find out, WHERE the Window should have its location?
And... "close" the form... how works that? Because, if it's a DialogForm i can't close it by clicking somewhere else!
modified on Tuesday, October 14, 2008 8:38 AM
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I am not getting right direction to add plugin for IE in C#.
In my project I added BHO .But I want to add it as a browser Extension.
If anyone knows how to do it.so help me out.
Will be very much thankfull to all....
email:bishu_473@yahoo.co.in
regards
bishwajeet
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I have a problem when I want call funtion in gridview by using templatefield.
The scenario is like this :
I want to call function : % of Compliance = getComplaince(field1,field2) in gridview. For your information field1 and field2 to in this gridview was set visible=false.
For example field1 = 1, field2 =1
The code is like below :
Field 1 Field 2 Application Definition % of Compliance
1 1 SMP Sistem Maklumbalas getCompliance(1,1)
2 1 E-App E-Application getComplaince(2,1)
getCompliance Function
1 public string getCompliance(int applicationID, int serviceID)
2 {
3 serviceCalculation c = new serviceCalculation();
4 string itemAB = c.getItemAB(serviceID, applicationID, lblError);
5 string[] splitItem = itemAB.Split(',');
6 string comply = c.countCompliant(splitItem[0].ToString(), splitItem[1].ToString());
7 return comply + "%";
8 }
getItemAB Function
1 public string getItemAB(int service, int applicationID, Label lblError)
2 {
3 database d = new database("S15TeRS");
4 int valueA = 0;
5 int valueB = 0;
6 double percentage = 0.0;
7 int counter = 0;
8 string query = "SELECT ss.ValueA,ss.ValueB,ss.Percentage FROM StateService ss" +
9 " INNER JOIN papv2.dbo.tblState s ON s.stateID = ss.stateID" +
10 " WHERE" +
11 " ss.ApplicationID='" + applicationID + "' AND ss.Service ='" + service + "'" +
12 " UNION" +
13 " SELECT ks.ValueA, ks.ValueB, ks.Percentage FROM KawasanService ks" +
14 " INNER JOIN papv2.dbo.tblKawasan k ON k.kawasanID = ks.kawasanID" +
15 " WHERE ks.ApplicationID='"+ applicationID +"' AND ks.Service='"+ service +"'" +
16 " UNION" +
17 " SELECT cs.ValueA, cs.ValueB, cs.Percentage FROM CawanganService cs" +
18 " INNER JOIN papv2.dbo.tblCawangan c ON c.cawanganID = cs.cawanganID" +
19 " INNER JOIN papv2.dbo.tblKawasan k ON k.kawasanID = c.cawanganID" +
20 " WHERE cs.ApplicationID='"+ applicationID +"' AND cs.Service='"+ service +"'";
21
22 try
23 {
24 d.Query = query;
25 d.InitDataReader();
26 while (d.findMoreRows())
27 {
28 counter++;
29 valueA += Int32.Parse(d.returnRow("ValueA"));
30 valueB += Int32.Parse(d.returnRow("ValueB"));
31 percentage += double.Parse(d.returnRow("Percentage"));
32 }
33 return valueA + "," + valueB;
34 }
35 catch (Exception ex)
36 {
37 lblError.Text = ex.Message.ToString();
38 return "";
39 }
40 }
41
countComplaint Function
1 public string countCompliant(string x, string y)
2 {
3 if (!(x.Trim().Equals("")) && !(y.Trim().Equals("")))
4 {
5 double a = double.Parse(x);
6 double b = double.Parse(y);
7 double compliant = b / a * 100;
8 double roundComplaint = Math.Round(compliant, 2);
9 return roundComplaint.ToString();
10 }
11 else
12 return "";
13 }
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Hi
I am trying to set two different background images to two different resolution monitors.
I know that i can use somthing like
<br />
const int SPI_SETDESKWALLPAPER = 20 ;<br />
const int SPIF_UPDATEINIFILE = 0x01;<br />
const int SPIF_SENDWININICHANGE = 0x02;<br />
<br />
[DllImport("user32.dll", CharSet=CharSet.Auto)]<br />
static extern int SystemParametersInfo (int uAction , int uParam , string lpvParam , int fuWinIni) ;<br />
<br />
<br />
and so on to get and set the wallpaper for a single monitor, but i am not sure how to expand this to work with 2 or more monitors.
I have had a look at the Screens.AllScreens class, but that seems more about the resolution and so on.
Anyone have any thoughts on how to do this?
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Does windows even support this ??
ASCII tables, HTML entities, types, string formats and more info for the serious coder at: www.codecharts.com
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I think theres a program called ultramon that can do it, and my nvidia graphics driver software can assign a diffferent image to each monitor.
Im very sure its possible.
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yeah. Makes sense that is is driver-dependent. I cant do it on my Matrox G550.
ASCII tables, HTML entities, types, string formats and more info for the serious coder at: www.codecharts.com
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I have been working on a notepad program that has sorting functions, I am having problems sorting large files, I have been getting outofmemoryexceptions, my test machines have had overkill amounts of memory, so that's not the issue. I have made sure to null and dispose my variables and objects, using "USING" code blocks as frequently as possible. I can't seem to solve this problem. I believe that an external sorting algorithm would be the only possible solution. But I can't find anything on it. I have read an outline of a the idea. but I just can't figure out how to implement one. I have scoured google, yahoo, ask, and dogpile for hours. there just doesn't seem to be any examples of a external merge sort anywhere. There is plenty of proof it exists, collage syllabuses with external merge sort in title, a wikki page describing its usage, I just can't find any C# help about.
if anyone could help me with an example, or a code snippet, or just a more in depth explanation that i might grow on.
I am at a loss,
Thanks,
DiamondDrake
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External sorting is just a term to mean a sort algorithm that can sort a large load of data without requiring it to all be loaded into memory at the same time.
The simplest example is the external merge sort. You just divide the data into equal sized blocks that you can handle. Sort each block and write it back to disk. Then load the first few values of each block into input buffers, and merge them into an output buffer. When the output buffer fills, write it to disk and clear it. If an input buffer empties, load some extra values from it's associated block.
This wikipedia article has a step by step process, and a few useful links. http://en.wikipedia.org/wiki/External_sort[^]
Before you consider this though, make sure you really need it. If you are sorting hundreds and hundreds of megabytes of data, then yes you need to do something like this. How big is the data file you are sorting? If it can sensibly be held in ram in one go, then you probably don't need to do external sorting.
Simon
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I appreciate the reply, and I am sorting text files that could possibly contain up to 4 million lines, I have written a method to sort lines of text by a column, or columns selected on the first line. this requires creating several copies of this 4 million line doc in memory. and leads to an out of memory exception, my method works perfect with 500 thousand lines or less, my test doc is 1 million lines, and it runs out of memory.
I get the idea, and i have read that wiki page already. I get the idea. I just don't understand how you can sort in chunks, I understand how to separated the document into parts, and sort each of those, then loading segments of each part and sorting those together and appending them to a file. but that doesn't actually sort all the data does it?
it doesn't seem right.
or at least I can't seem to get it to work right.
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Easiest thing is probably an example.
Take the numbers 0 to 9.
1 7 3 5 2 9 8 4 6 0
Lets assume you can only load 5 at a time into memory.
Load the first block of 5.
1 7 3 5 2 - Lets call this block A.
Now sort block A, using what ever method you want.
1 2 3 5 7.
Now save block A to disk.
Now load the next block.
9 8 4 6 0 - Lets call this block B.
Sort block B.
0 4 6 8 9.
Now save block B to disk.
A - 1 2 3 5 7
B - 0 4 6 8 9
Now you create an input buffer for each block, and 1 output buffer
In this case, we've already said we can manage 5 in memory at a time, so lets make our input buffers 1 item big, and our output buffer 3 items big.
Load the first items from blocks A & B into the input buffers.
InA: 1
InB: 0
Out: Nothing yet.
Now you take the lowest of all the input buffers. In this case buffer B. Move it to the output buffer.
InA: 1
InB: Empty
Out: 0
As buffer B is now empty, you load the next item from B into the buffer. (In this case 4)
InA: 1
InB: 4
Out: 0
Now you just repeat the process. So you move the lowest value to the output buffer.
InA: Empty
InB: 4
Out: 0 1
Then load the next item from A into the empty input buffer.
InA: 2
InB: 4
Out: 0 1
Then move the lowest to the output buffer
InA: Empty
InB: 4
Out: 0 1 2
Now the output buffer is full (remember we said the output buffer was 3 big). So you write the output buffer to disk.
InA: Empty
InB: 4
Out: Empty
Final sorted on disk: 0 1 2
Now you need to load the next value from block A (because InA has become empty)
InA: 3
InB: 4
Out: Empty
Then move the lowest to the output buffer
InA: Empty
InB: 4
Out: 3
Then load the next for any empty input buffers
InA: 5
InB: 4
Out: 3
Move lowest to the output buffer
InA: 5
InB: Empty
Out: 3 4
Load for any empty input buffers
InA: 5
InB: 6
Out: 3 4
Is it starting to be clear now?
1st, Divide into manageable blocks.
Sort each block and write back to disk.
Load the first bit of each block into an input buffer.
Process the input buffers, and move the lowest value into the output buffer.
Every time an input buffer runs empty, you load the next few data items from the associated block.
Every time the output buffer fills up, you write it to disk, and append it to the data already there.
Obviously, this is a simple example. You wouldn't really do this with a list of 10 numbers. And your block sizes and buffers would be much bigger.
Essentially, it's just a merge sort, but your not keeping each block in memory.
Good luck
Simon
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 Thanks, It makes perfect sense now. I appreciate it endlessly.
DiamondDrake
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how can i use that treeview in crystal report viewer? it´s always blank.
At least in the sample codes i download!!! 
nelsonpaixao@yahoo.com.br
trying to help & get help
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I have a database that has many types of variables; varchar, int, date, image.
I connect it to my c# application, even builted a fine dataset to fit my report.
OK, all data is present in my report, but the images aren´t there!!!
The IBLOBfieldObject suitable for pictures is always blank.
In dataset the image is a byte[], right? YES
I even trigger the same procedure in a datagridview and the pictures appear there!!!
I dont have a clue
nelsonpaixao@yahoo.com.br
trying to help & get help
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