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A dataset returns a collection of DataTables, in this case it would only contain one Table. I don't think it is possible to query DataSets using SQL. You would need to iterate through the table until you found an ID matching 1 and retrieve the name. Personally I prefer to use XML literals and LinQ to retrieve data from xml files like this
Dim datatest As XDocument = XDocument.Load("Test.xml")
For Each student In From element In datatest...<Tab1>
If student...<ID>.Value = 1 Then
name = student...<Name>.Value
Exit For
End If
Next
MsgBox(Name)
That makes everything very concise and readable.
Hope this helps.
Happy Coding
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Is that only one way to do quering a dataset?
I tried Dataset.Select("ID=1") but it is not enought for my requirement.
anyway thanks.
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You could always bind the data to a bunch of controls e.g. bindingsource, bindingnavigator and datagridview and then use the FILTER property of the BindingSource, as it acts just like a 'where' clause in SQL.
Dave
Don't forget to rate messages!Find Me On: Web| Facebook| Twitter| LinkedInWaving? dave.m.auld[at]googlewave.com
modified on Thursday, July 15, 2010 10:10 AM
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i have an examination system that will be run twice a year. some of the tables are setup some are transactional. should i archive or backup at end of each processing
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yes, obviously.
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i mean which onewill be better
modified on Wednesday, July 14, 2010 12:09 PM
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that sounds like a functional question; I can't decide what functionality you need, you should know.
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Surely that depends on couple of things;
1) is the old data still required to be accesssed regularly
2) is the storage system running out of space
there are probably other factors........
If the data is no longer required to be routinely accessed and/or you are short of space, then archive out to another medium.
As for backup, you should be running routine incremental or full backup whenever you feel it is appropriate given the value of the data and business impact in the event of a data interruption.
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dear all
this is first time for me to use winsock in vb6, i don't how to exchange data in 2 different exe, although i searched online, but i still didn't get what i expect. anyone can tell me this point--step by step. thanks a lot.
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zhiyuan16 wrote: this is first time for me to use winsock in vb6, i don't how to exchange data in 2 different exe,
There's a basic example here[^]. Best way to go would be to analyze examples, and try to build something similar.
zhiyuan16 wrote: although i searched online, but i still didn't get what i expect. anyone can tell me this point--step by step.
That begs the question on what you're expecting, and what the requirements for the communications are.
I are Troll 
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Hi,
Following sample shows the use of Winsock in vb6. Just copy, paste & Test.
To Test in local mode (if currently u don't have two machines connected)
Make "yourproject.exe" & run in double instance then:
in 1 instance click Listen(Command2) And another click Connect(Command2).
Then Type text in Text3 and click on Send(Command3).
Option Explicit
Private Sub Command1_Click()
Winsock1.Connect Me.Text1, Me.Text2
End Sub
Private Sub Command2_Click()
Winsock1.LocalPort = Me.Text2
Winsock1.Listen
End Sub
Private Sub Command3_Click()
Winsock1.SendData Me.Text3.Text
Me.Caption = "Local Send" & Me.Text3.Text
End Sub
Private Sub Winsock1_DataArrival(ByVal bytesTotal As Long)
Dim AD As String
Winsock1.GetData AD
Me.Caption = "Remote: " & AD
End Sub
Private Sub Winsock1_ConnectionRequest(ByVal requestID As Long)
On Error Resume Next
Winsock1.Close
Winsock1.Accept requestID
Me.Caption = "Request accepted"
End Sub
Private Sub Winsock1_Close()
Me.Caption = "Closed"
End Sub
Private Sub Winsock1_Connect()
Me.Caption = "Chat Started at " & Time
End Sub
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i bind a datagridview(window form) to a datable. but i added extra checkbox column from design . i notice it does not check whn i run it
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Normally this should work, even if your datatable (rows) is empty.
How did you work things out, exactly?
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i have resolve. i need to check editing thanks
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I am using the following borrowed code to insert an image into an RTF, as that aspect of RTF seemed way beyond me
[code]Public Sub InsertImage(ByVal _image As Image)
Dim _rtf As New StringBuilder()
' Append the RTF header
_rtf.Append(RTF_HEADER)
' Create the font table using the RichTextBox's current font and append
' it to the RTF string
_rtf.Append(GetFontTable(Me.Font))
' Create the image control string and append it to the RTF string
_rtf.Append(GetImagePrefix(_image))
' Create the Windows Metafile and append its bytes in HEX format
_rtf.Append(GetRtfImage(_image))
' Close the RTF image control string
_rtf.Append(RTF_IMAGE_POST)
Me.SelectedRtf = _rtf.ToString()
End Sub
Private Function GetImagePrefix(ByVal _image As Image) As String
Dim _rtf As New StringBuilder()
' Calculate the current width of the image in (0.01)mm
Dim picw As Integer = CType(Math.Round((_image.Width / xDpi) * HMM_PER_INCH), Integer)
' Calculate the current height of the image in (0.01)mm
Dim pich As Integer = CType(Math.Round((_image.Height / yDpi) * HMM_PER_INCH), Integer)
' Calculate the target width of the image in twips
Dim picwgoal As Integer = CType(Math.Round((_image.Width / xDpi) * TWIPS_PER_INCH), Integer)
' Calculate the target height of the image in twips
Dim pichgoal As Integer = CType(Math.Round((_image.Height / yDpi) * TWIPS_PER_INCH), Integer)
' Append values to RTF string
_rtf.Append("{\pict\wmetafile8")
_rtf.Append("\picw")
_rtf.Append(picw)
_rtf.Append("\pich")
_rtf.Append(pich)
_rtf.Append("\picwgoal")
_rtf.Append(picwgoal)
_rtf.Append("\pichgoal")
_rtf.Append(picw)
_rtf.Append(" ")
Return _rtf.ToString()
End Function
<DllImportAttribute("gdiplus.dll")> _
Private Shared Function GdipEmfToWmfBits(ByVal _hEmf As IntPtr, ByVal _bufferSize As UInt32, ByVal _buffer As Byte(), ByVal _mappingMode As Integer, ByVal _flags As EmfToWmfBitsFlags) As UInt32
End Function
''' <summary>
''' Wraps the image in an Enhanced Metafile by drawing the image onto the
''' graphics context, then converts the Enhanced Metafile to a Windows
''' Metafile, and finally appends the bits of the Windows Metafile in HEX
''' to a string and returns the string.
''' </summary>
''' <param name="_image"></param>
''' <returns>
''' A string containing the bits of a Windows Metafile in HEX
''' </returns>
Private Function GetRtfImage(ByVal _image As Image) As String
Dim _rtf As StringBuilder = Nothing
' Used to store the enhanced metafile
Dim _stream As MemoryStream = Nothing
' Used to create the metafile and draw the image
Dim _graphics As Graphics = Nothing
' The enhanced metafile
Dim _metaFile As Metafile = Nothing
' Handle to the device context used to create the metafile
Dim _hdc As IntPtr
Try
_rtf = New StringBuilder()
_stream = New MemoryStream()
' Get a graphics context from the RichTextBox
Using _graphics1 As Graphics = Me.CreateGraphics()
' Get the device context from the graphics context
_hdc = _graphics1.GetHdc()
' Create a new Enhanced Metafile from the device context
_metaFile = New Metafile(_stream, _hdc)
' Release the device context
_graphics1.ReleaseHdc(_hdc)
End Using
' Get a graphics context from the Enhanced Metafile
Using _graphics1 As Graphics = Graphics.FromImage(_metaFile)
' Draw the image on the Enhanced Metafile
_graphics1.DrawImage(_image, New Rectangle(0, 0, _image.Width, _image.Height))
End Using
' Get the handle of the Enhanced Metafile
Dim _hEmf As IntPtr = _metaFile.GetHenhmetafile()
' A call to EmfToWmfBits with a null buffer return the size of the
' buffer need to store the WMF bits. Use this to get the buffer
' size.
Dim _bufferSize As UInt32 = GdipEmfToWmfBits(_hEmf, 0, Nothing, MM_ANISOTROPIC, EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault)
' Create an array to hold the bits
Dim _buffer As Byte() = New Byte(CInt(_bufferSize)) {}
' A call to EmfToWmfBits with a valid buffer copies the bits into the
' buffer an returns the number of bits in the WMF.
Dim _convertedSize As UInt32 = GdipEmfToWmfBits(_hEmf, _bufferSize, _buffer, MM_ANISOTROPIC, EmfToWmfBitsFlags.EmfToWmfBitsFlagsDefault)
For i As Integer = 0 To _buffer.Length - 1
' Append the bits to the RTF string
_rtf.Append([String].Format("{0:X2}", _buffer(i)))
Next
Return _rtf.ToString()
Finally
If _graphics IsNot Nothing Then
_graphics.Dispose()
End If
If _metaFile IsNot Nothing Then
_metaFile.Dispose()
End If
If _stream IsNot Nothing Then
_stream.Close()
End If
End Try
End Function
[/code]
sorry for so much code, anyway if i use that, the image is huge, here is a sample untouched image
i tried inserting the image with wordpad and copying the picw, pich, pichgoal, and picwgoal values from the wordpad generated RTF, but then the image looked almost squeezed together. i did notice the image hex values seemed quite different, i can't simply copy as the image itself will be different each run, I am at a loss, any help is appreciated
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Yuck.
Put your code in a code block and write in paragraphs.
Also, put the question at the top and refer to code below, it makes it much more likely people will help.
They will not want to wade through treacle to get to the question.
Anyways, hav you tried to shrink the image?
------------------------------------
I will never again mention that I was the poster of the One Millionth Lounge Post, nor that it was complete drivel. Dalek Dave
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Formating the code would help but never mind. Looks like a typo.
djdrew wrote: Append values to RTF string
_rtf.Append("{\pict\wmetafile8")
_rtf.Append("\picw")
_rtf.Append(picw)
_rtf.Append("\pich")
_rtf.Append(pich)
_rtf.Append("\picwgoal")
_rtf.Append(picwgoal)
_rtf.Append("\pichgoal")
_rtf.Append(picw)
_rtf.Append(" ")
Should be :
_rtf.Append("{\pict\wmetafile8")
_rtf.Append("\picw")
_rtf.Append(picw)
_rtf.Append("\pich")
_rtf.Append(pich)
_rtf.Append("\picwgoal")
_rtf.Append(picwgoal)
_rtf.Append("\pichgoal")
_rtf.Append(pichgoal)
_rtf.Append(" ")
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thank you both, i apologize as i'm very new here and not used to posting at all, i'll try to get more familiar with the proper way and give your solution a try as well, i can't believe i didn't notice that
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Hi,everyone!I used a treeview control in a splitcontainer,I want it to work like frame web:when I click one node,some controls display on right.I wrote the NodeMouseClick Event like these:
Private Sub treeQiaoTi_NodeMouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeNodeMouseClickEventArgs) Handles treeQiaoTi.NodeMouseClick
If e.Node.Text = "abc" Then
panJieGuan2.Visible = False
Panel1.Visible = True
Else
Panel1.Visible = False
panJieGuan2.Visible = True
End If
End Sub
When I clicked the node "abc",the panel1 displayed on right,but after I clicked other nodes,panJieGuan2 is not shown.
panel1 and panJieGuan2 were all on splitcontainer right panel,panJieGuan2 was above panel1.
PLZ give me some suggestions and help me !!THX!
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Have a look at this link click here
but a snippet here shows how to read a selected node into a label
Public Class Form12 Inherits System.Windows.Forms.Form
#Region " Windows Form Designer generated code "
#End Region
Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As_
System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
Label1.Text = "You are here->" & " " & e.Node.FullPath
'displaying the path of the selected node
Label2.Text = "Current node selected:" & " " & e.Node.Text
'displaying the selected node
End Sub
End Class
As barmey as a sack of badgers
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Hi,Simon!Emmmmm...I think your suggestion is that I should write other event to get selectnode?
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something else you could try is on your current method is
messagebox.show TreeView1.SelectedNode.Text
where treeview1 is the name of your treeview
As barmey as a sack of badgers
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Simon,I use msgbox to show the select node,I found that it got forcus on mouse click,emm...,I means when I click "123",the e.node is really "123",and this time the controls occured.
But I found another question.For example,Panel 2 was on Panel 1,Panel 2 relies on Panel 1.I want when I clicked node 1,Panel 1 should display;when I clicked node 2,Panel 2 should display.Could you tell me how could do this?
Thanks a lot!
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If panel1 is a child of panel2 OR Panel2 is a child of Panel1 you'll never see child panelin your form.
Check the following Code:
Private Sub treeQiaoTi_NodeMouseClick(ByVal sender As Object, ByVal e As System.Windows.Forms.TreeNodeMouseClickEventArgs) Handles treeQiaoTi.NodeMouseClick
Me.Text = e.Node.Text
If e.Node.Text = "abc" Then
panJieGuan2.Visible = False
Panel1.Visible = True
Panel1.BringToFront()
Else
Panel1.Visible = False
panJieGuan2.Visible = True
panJieGuan2.BringToFront()
End If
End Sub
This is not Necessary yet:
Private Sub treeQiaoTi_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles treeQiaoTi.AfterSelect
End Sub
Use <pre lang="vb"> Visual Basic Code Here.</pre>
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Hi,Aslam，thank you very much!
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