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i'm trying to update a checkbox state from vb to an ms access database.
can anyone fix my code for me pleae?
it says "no value given for one or more parameters(what does this mean?).
Imports System.Data.OleDb
Public Class Block
Public conn As OleDbConnection
Public comm As OleDbCommand
Public dr As OleDbDataReader
Public da As OleDbDataAdapter
Dim icount As Integer
Private Sub Btnblock_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnBlock.Click
'when the logon button is pressed
Dim ManagerLogin As String
'declares the variable
Try
conn = New OleDbConnection 'establishes that conn is a new connection
conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=|DataDirectory|\PCBank.mdb" 'the name of the connection (name of the database on the end)
conn.Open() 'opens the connection
comm = New OleDbCommand 'establishes that comm is a new command
comm.Connection = conn 'the connection for the command is the connection specified
comm.CommandType = CommandType.Text 'the commands are in text
ManagerLogin = "SELECT DISTINCT Password FROM Accounts WHERE ManagerID='" & Me.tbID.Text & "' "
'the variables value is an SQL command, selects value that is equal to the id AND password.
''MessageBox.Show(ManagerLogin) 'shows the sql command (only needed for testing)
comm.CommandText = ManagerLogin 'the variable is declared as a command
dr = comm.ExecuteReader 'gives the variable a value
conn = New OleDbConnection("provider=microsoft.jet.oledb.4.0;data source=PCBank.mdb")
conn.Open()
comm = New OleDbCommand("update into Accounts(Blocked) values('" & (chBlock.CheckState) & "')", conn)
icount = comm.ExecuteNonQuery()
MsgBox("record inserted")
chBlock.Checked = False
Catch ex As Exception
MsgBox(ex.Message)
If dr.Read() Then (it doesn't like this line either)'if the entry is correct (readable)
Me.Close()
Form2.Show() 'show the index varibale (form)
'close the current form
Else 'if the entry is incorrect
MessageBox.Show("Invalid ID, please try again") 'displays error message
tbID.Clear() 'clears the managerid
End If 'end if
End Try
conn.Close()
End Sub
Private Sub Block_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
End Sub
End Class
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Problem could be that you're trying to use a data reader object to do the update when a data reader provides forward-only, read-only access.
You may find this[^] helpful when it comes to using data readers.
For updating a database you should rather use a DataAdapter[^].
Seems like you're using .NET 1.1, right?
Also, why are you initializing & opening your connection object twice? If it's not giving you errors it's at least incurring unnecessary overheads. Try refining your code to be a bit simpler, you'll feel the benefit in time 
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Hi,
I've created an application to save a picture from a webcam as a BMP, but this image is saved at 320x240 pixels.
What i would like to do is after saving this image, have vb open it up in a non visible picture box if need be, and save then crop at 162*197. i have used avicap32.dll and user32.dll . now plz tell me about croping.
Regards
Msaqlain
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I just answered this question, did you try what I told you before asking it again ? You don't need those dlls, all you need to do is redraw the image section you want on a smaller bitmap.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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hi dear i have developed a program in vb.net that just connect my webcame and take pic now i want to make a function that will crop my pictures so for that give me any help about it any function or any compoenet etc.
Regards
Msaqlain
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Once the image has been captured, you can just draw any portion of it onto a new Bitmap, so create one the right size and draw the portion you require onto it.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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hey, i am working on a voice command and control project, our pc works as we give it command through mike.
i can open,close, mininize,maximize applications like notepad, wordpad, run, taskmanager through my programm.
but i want to get wave file info which is taken as input to pc. and through i want my project to work more efficientely, and accurately.
does anyone know??
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sanket h modi wrote: i want to get wave file info which is taken as input to pc. and through i want my project to work more efficientely, and accurately.
What do you mean by "work more efficientely, and accurately"?? That's a very generic and subjective description that can be applied to any aspect of your PC or application. You'ce going to have to be more specific about what you want.
Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007
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You can either write your own installer, or use something like Wise for Window Installer to build one.
Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007
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Hello all,
Does anyone know how to show more than one database collumns in a listbox??
In documentation i read that it was not possible bus is there anyone who knows a backdoor for it?
Thanks.
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if you just want to display data then while retrieving Concatenate it in sql query........but i dont think u can see more than one column in a listbox..may be i am wrong
Tirtha
Miles to go before I sleep
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Use a ListView.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
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Is it that easy?
Shame on me!!
I wil try it.
Thanks
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But how will i bind the listview to the database table?
There is no datasource property.
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ListView doesn't have any datasource property...u have to add Items and Subitems to display ur data....
Tirtha
Miles to go before I sleep
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If you need an object exposing the DataSource property then use the DataGrid.
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
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if u have a dataset(say myDataset) populated with your records then try this....(code is in vb.net)
Dim lvItem As ListViewItem<br />
For i As Integer = 0 To myDataset.Tables(0).Rows.Count - 1<br />
lvItem = New ListViewItem(myDataset.Tables(0).Rows(i).Item(0))<br />
For j As Integer = 0 To NumberOfSelectedField<br />
lsItem.SubItems.Add(CStr(myDataset.Tables(0).Rows(i).Item(j + 1)))<br />
Next<br />
myListView.Items.Add(lvItem)<br />
Next
Tirtha
Miles to go before I sleep
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Hello,
Which Exception appears when inserting duplicated data (primairy key) in a database?
In my application "System.Data.OleDb.OleDbException" appeared but that seems to general to me??
And how can i use the try, catch statement?
Thanks
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That looks about right, it's a database exception, and there are not exceptions defined for everything that can happen in the DB. The text of the exception will explain it
keninfo wrote: And how can i use the try, catch statement?
If you really don't know how to use try/catch, you probably need to buy a book on VB and work through it. Or, at least try google.
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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I know a little how try catch is working but can you help me a little ?
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Try
' do your processing here
Catch (WhateverException As Exception)
' handle the error here
Finally
' any additional processing that needs
' doing regardless of error handling
' release database connections, etc.
End Try
Read this[^] for more info.
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Well, I assume you knew what you've been told ( as it's the bare bones of what try/catch does ). What did you need to know ?
Christian Graus - Microsoft MVP - C++
Metal Musings - Rex and my new metal blog
"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )
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How to get the current page number in ms word using vb.net.
i like to get the hyperlinks count in each page including the footnotes hyperlink and to store in an array
Thanks,
Nanda
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