Visual Basic

Re: sorting a subset of a datatable in a different order

4-Oct-11 3:30

First, sorting is only applicable to records shown to the user. Databases do not care about record order, so sorting them and writing the sorted records back to the database does absolutely nothing. The records will not be moved aorund to the new sorted order.

So, what's the point of all this?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Armigo4-Oct-11 22:52

Armigo

4-Oct-11 22:52

Hi Dave,

thanks for your reply. I'm working with ADO-classes and i fill my datatable (ADO-class) with data from my database. I use the "ORDER BY"-statement in my SQL-string to fill my datatable in the needed order. But at one specific part i need to change the order.

For example, i fill my datatable via a tableadapter (also ADO-class) with the SQL-Statement

SQL

SELECT * FROM myDB ORDER BY a, b DESC

Then, the data are stored in my datatable in exact the order given by the statement. I go through my datatable an do some calculations with my records. When i reach - lets say - record No.30, i want to change the order of the next 10 records. After the 10 records, the order should remain the same as before.

I hope you could understand it better now.

Re: sorting a subset of a datatable in a different order

Simon_Whale4-Oct-11 23:36

Simon_Whale

4-Oct-11 23:36

If I understand you correctly you

Want to modify your a subsection of your datatable with a new order which still sits within the same datatable?

If I have this correct then as far as I am aware there is no existing method that can do this other than making yourself a routine to rebuild the datatable in the order that you want

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

Re: sorting a subset of a datatable in a different order

Dave Kreskowiak5-Oct-11 4:46

Re: sorting a subset of a datatable in a different order

5-Oct-11 4:46

Well, You'd have to build your own DataView from the data in the DataTable object, adding the records you need in the order you need them. You will have to implement your own sorting algorithm to do this.

In your example, you'd have to add records 0 through 29, then create a collection of records 30 through 40, send that to be sorted, then add those sorted records to the view, then add the remaining records.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Armigo10-Oct-11 2:30

Armigo

10-Oct-11 2:30

Hello everybody and thanks for your replies,

i could manage to solve the problem with the algorithm presented in my first post. Here is my solution for those, who are interested in it:

iBlockRowStart = iCurrentRow
iBlockRowStop = iBlockRowStart

' Step 1: The first row of the block is recognized through a previous if-inquiry. Now get the last row with the appropiate condition - in this case the block ends until the day of week in the current row isn't friday
' DS is my DataSet, which is already filled with data 

Do While System.Convert.ToDateTime(DS.Tables("AnyTable").Rows(iBlockRowStop).Item("Date")).DayOfWeek = dayofweek.Friday
	iBlockRowStop = iBlockRowStop + 1
	If iBlockRowStop = DS.Tables("AnyTable").Rows.Count Then
		Exit Do
	End If
Loop
iBlockRowStop = iBlockRowStop - 1
						
' Step 2: Clone tablestructure and then copy block-rows to a new, temporary datatable
tempTable = DS.Tables("AnyTable").Clone()
For j = iBlockRowStart To iBlockRowStop
	tempTable.ImportRow(DS.Tables("AnyTable").Rows(j))
Next
						
' Step 3, 4 & 5: Assign Data to DataView, Sort Data and reassign to new DataTable
View = tempTable.DefaultView
View.Sort = "ColA, ColB"
Dim tempTable2 as DataTable = View.ToTable()
						
' Step 6: Copy datarows of tempTable2 into the section of the table in my DataSet, specified by my indices
For j = iBlockRowStart To iBlockRowStop
	For k = 0 To tempTable2.Columns.Count - 1
		DS.Tables("AnyTable").Rows(j).Item(k) = tempTable2.Rows(j - iBlockRowStart).Item(k)
	Next
Next

With this piece of code it is possible to sort a part of a datatable in a dataset in another order. In my case, i needed this repeatedly when the date of my record was friday. I needed to sort my "friday-records" in another order. My datatable was filled with data of a month, so i had four fridays...

Thanks again for your help!

Re: sorting a subset of a datatable in a different order

Luc Pattyn4-Oct-11 4:08

Luc Pattyn

4-Oct-11 4:08

Not sure I understand you, however if the sort I get wouldn't do what I want I would:

1.
either: provide a better comparer (implement ICompare, which is very easy) and have the built-in Sort use that;
here[^] is a little article on the subject.

2.
or: add a column (possibly never to be shown), make sure its cells get numbered in the order I want, then sort on that column.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

adding a reference System.Web.UI

Minenhle Ndlovu3-Oct-11 3:20

Minenhle Ndlovu

3-Oct-11 3:20

Hi please help

How can i add the reference to my windows form here is my references

Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls---here is giving me an error
Imports System.Net
Imports System.Configuration
Imports System.Text.RegularExpressions
Imports System.IO
Imports System.Text
Imports System.Web.UI.HtmlControls----here is giving me errors again...

I am sending an sms from windows form...

Dave Kreskowiak3-Oct-11 3:39

3-Oct-11 3:39

If all you're doing is send an SMS you don't need the references to System.Web.UI and System.Web.UI.WebControls, nor System.Web.UI.HtmlControls, unless, of course, you're writing an ASP.NET application and not a Windows Forms app.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Luc Pattyn3-Oct-11 4:27

Luc Pattyn

3-Oct-11 4:27

Minenhle Ndlovu wrote:
here is giving me an error

and I bet the error message is telling you exactly what is wrong.
BTW: if you don't understand the error message, it would still be wise to post it so others who do can help.

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Simon_Whale3-Oct-11 4:46

Simon_Whale

3-Oct-11 4:46

You need to add a reference to the system.web .net library in your application

Lobster Thermidor aux crevettes with a Mornay sauce, served in a Provençale manner with shallots and aubergines, garnished with truffle pate, brandy and a fried egg on top and Spam - Monty Python Spam Sketch

How to print multiple reportviewer report on a single button?

Eddy Vluggen3-Oct-11 8:30

Eddy Vluggen

3-Oct-11 8:30

Minenhle Ndlovu wrote:
How can i add the reference to my windows form here is my references

Those are imports; it says what is being imported in that unit, from all the references that are available in your project.

Are you using Visual Studio? If so, go to the "Project" menu and choose "Add reference" from there. Both SharpDevelop and MonoDevelop have a similar options. If you're using a text-editor, you'll have to edit the project by hand.

Bastard Programmer from Hell Suspicious | :suss:

C#Coudou2-Oct-11 13:46

C#Coudou

2-Oct-11 13:46

Hi all,

In access, we can print multiple report in a single button, how
to do that in asp.net? I'm using report viewer.
I really appreciate who can gave me a detailed solution. I ask already google.

Thanks in advance!

C# コードMicrosoft End User
2000-2008

「「「「「「「「「「「「「「「「「「「「「「「「「「「「
The best things in life are free
」」」」」」」」」」」」」」」」」」」」」」」」」」」」

How to create my own spammer with VBscript

Shubhamraj1-Oct-11 20:01

Shubhamraj

1-Oct-11 20:01

Hey.Frnds...I want to know how to create my own Spammer wid Vbscript....Plz Give me answer of this..Plz describe wid Basics frnds...

Richard MacCutchan1-Oct-11 21:29

Richard MacCutchan

1-Oct-11 21:29

Not here!

Unrequited desire is character building. OriginalGriff

Dalek Dave1-Oct-11 22:44

Dalek Dave

1-Oct-11 22:44

Certainly.

All you need to do is get some education, a decent job and a sexual partner.

Then you won't need to be a complete arse.

It is the sort of thing that morons and losers do, and it shows you are someone in need of a life.

------------------------------------

I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave

CCC Link[^]
Trolls[^]

Sander Rossel2-Oct-11 0:16

Sander Rossel

2-Oct-11 0:16

It's an OO world.

public class Naerling : Lazy<Person>{}

Richard MacCutchan2-Oct-11 1:49

Richard MacCutchan

2-Oct-11 1:49

I do like the subtleties in your use of language.

Unrequited desire is character building. OriginalGriff

Dave Kreskowiak2-Oct-11 1:57

2-Oct-11 1:57

Your asking a bunch of people who HATE spam with a passion how to write something that send that stuff out?? And you call us "friends"??

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Re: Playing with services

Bert Mitton3-Oct-11 3:10

Bert Mitton

3-Oct-11 3:10

Thanks for the laugh. It's a rough Monday morning, and I needed it.

Playing with services

DeDelva30-Sep-11 2:15

DeDelva

30-Sep-11 2:15

Hello All,

I'm playing with interactions between excel and vb.net...

Everytime i start an excel application it become's one of my processes in my taskbar.

I always put my vars from workbook,sheets,app to nothing at the end
i collect my garbage

But wath do i forget to dispose this from the services??

I'm kind a noob so can somebody provide me some help?

I just want to clean up after using...

oSheet = Nothing
           oBook = Nothing
           oExcel.Quit()
           oExcel = Nothing
           GC.Collect()

Thx in advance

Dave Kreskowiak30-Sep-11 3:36