I have a single user app that I wrote and have been using for more than a year that uses an Access 2003 database. Today, out of the blue, I started getting a DB concurrency violation whenever I tried to update one particular table in the database. After trying to troubleshoot what the problem might be, I just deleted that table and recreated it and the problem went away.
View 2 RepliesMy client recently got this error but I can't reproduce it on my pc. Any Idea what the problem could be. I have a master/detail scenario. So I have a grandparent/parent relationship, so when I select a product from my product combobox it displays the relevant results from the Result_Header table in my first datagridview.
Then I have a parent/child relationship so that when I select a result_header item from my first datagridview it displays the child records from the Result_detail table. If i'm adding a new Result_Header and then click save, I search for existing tests for the chosen product and insert them as new datarows into the Result_detail table. then I can update the child rows and click the second save button and it saves what I edit. Quite complicated.
Dim data As DataSet
Private dbpath As String = My.Settings.dbpath
Private con As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;" _
& "Data Source=" & dbpath & ";Persist Security Info=False;")
[code]....
My users are getting this error when trying to update the database:
"Concurrency violation: UpdateCommand affected 0 of the expected 1 records"
All the users are doing is clicking a button which updates a record.No two users are updating the same record or even within the same column. They could be updating within the same row but still not the same record.It seems to be happening when the program is open for a little while and they come back and try to update the database through the program. I have read a little bit about this error but none seem to lead to a clear solution.It seems like the database connection is timing out due to inactivity?Here is my update command:
vb.net
Private Sub btnComplete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnComplete.Click
Me.txtComplete.Text = Date.Today[code].....
I'm having an issue with a concurrency violation when I save my data(only on one form). All other data forms are working fine. This form has a lot of code, so to isolate the problem I added a new form to the project and dragged the table from my datasource, in detail, to the form. this is the only code in the form,
[Code]....
I am trying to make a simple demo of a DataGridView bound to a database table. I want to add a row, delete a row, and save the table. I used the IDE to do just about everything. It created the BindingSource when I set the datasource of the DataGridView to a table of a DataSource I added to the project.
Now the only code looks like this:
Public Class Form1
Private Sub DataGridView1_CellContentClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles DataGridView1.CellContentClick
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[Code] .....
I set the AutoIncrementStep to 1 in my Key field in the dataset (the .xsd). I left the Key field visible in the DataGridView and it seems to be adding the correct Key when a row is added. However, I still occasionally get the "concurrency violation" error if I just mess around with these 3 buttons. Any idea why/how to prevent that?
get around the following problem please?I have an Access database which can be accessed by more than one instance of my application (which is) a Form with a DataGridView on it.I populate the DGV with
Form1.Validate()Form1.CHECKLISTBindingSource.EndEdit()Form1.CHECKLISTTableAdapter.Update(Form1.chkDataSet.CHECKLIST) The Access Database can then be updated via the DGV by a button click (which runs the code above (to copy across the latest copy of the DB) and then runs the code below to copy your changes to the DB)
Form1.CHECKLISTTableAdapter.Fill(Form1.chkDataSet.CHECKLIST)
Form1.DataGridView4.DataSource = Form1.CHECKLISTBindingSource
Form1.DataGridView4.Refresh()
The Access table is basicaly a 'Time' Column and a 'Name' Column.
[Code]...
I'm trying to update a Access database. I'm new to this and I've reviewed an Ado tutorial early today. I'm trying to apply what is taught but I'm getting an error message and I can't seem to get passed it.
In my code I have an Add, Update, and Delete process. The Add and Delete processes work just fine. It is only when I go to update the database that I get the following message."Concurrency violation: the UpdateCommand affected 0 of the expected 1 records."
[Code]...
When my project starts, it first checks for the existence of certain rows in the database. During testing, I often delete these rows, as they get kind of messed up over time due to all the odd tests I am running. For that reason, if when the project starts, if the records are not there, the program first creates them.The records are pretty static over the lifetime of the project, so they are held in a dataset for ready access from various parts of the program. Therefore, if the records are not in the database, the records are added to the dataset, and the dataset is updated back to the database. This works without any issues.However, one of the easiest actions to take will cause one of these records to change two fields, and a new record will be added. Those are all the changes that are caused by this action. Those changes are then updated to the database...or so I hoped, but when I try that I get an exception stating:[code]I have looked at the datatable that is being updated, and there are, as I expect, two records being changed. One of the records is the new one that is being added, while the second record is the record that was changed. I have noted that the change is, in fact, different from what is in the database, so this really IS an update.
However, I also noted that if I then stop the program and start it again, all is well. This indicated to me that it was actually the routine that created the records that was causing the trouble. Therefore, to test this out, I tried a totally horrible solution. I altered the method that writes to the new records to the database so that after it wrote each record, it would clear the whole dataset and fill it all again. That's obviously a terrible thing to do, but it works. If I write each record, throw out the dataset and re-create it, then I don't get any exceptions when I later try to modify it.This makes no sense to me. What am I doing in that first method that could be putting the Dataset into a state where it fails on any further modifications? I should add that the code that actually pushes the changes to the dataset down to the DB is the same for both methods. In fact, the database is updated in an UpdateDB method that is called from that first method (which creates the initial records if they are missing), as well as being called by the other methods that alter the dataset. I have also confirmed that ANY alterations I want, whether they add, remove, or just alter records, works fine. It is only that one method that creates the initial records that is causing me trouble. Moreover, it is not the actual update of the DB that is doing it, since that same method works fine ever after. Further testing has showed that the issue is row by row. As each initial row is added, it can't be modified by any other code until the dataset has been re-read from the DB. url...
A concurrency violation error? It happens on this statement:
CODE:
It thinks I'm using a key value of 1 when the actual value is really 1218. I'm using a command builder. The attachments show the value of the key value and the value of the update text values. By the way, I can insert data but not update it.
I'm having some trouble updating changes I made to a datatable via a dataadapter. I am getting "Concurrency violation: the UpdateCommand affected 0 of 10 rows"
'Get data
Dim Docs_DistributedTable As New DataTable("Docs_Distributed")
Dim sql = "SELECT DISTINCT CompanyID, SortKey, OutputFileID, SequenceNo, DeliveredDate,
[code].....
This code used to work but for some reason it doesn't anymore. I get the error "Concurrency violation: the DeleteCommand affected 0 of the expected 1 records." I checked to see if the values were in the db and they were, by the way I'm using Access 03. I commented out the try/catch block and got the error when trying to update the ds.
[Code]...
im using a sqldataadapter, dataset and bindingsource to connect to a table. i retrieve all records from the database and i change the data on a field then update changes to database. when i try to change back to original value i get a Concurrency violation error (concurrency violation: The updatecommand affected 0 of the expected 1). this is the
Try
Me.Validate()
Me.sqlBindingSource.EndEdit()
Dim slqCmdBuilder As New SqlCommandBuilder(sqlAdapter)
[Code].....
When I run the following code I get the error "Concurrency violation: the DeleteCommand affected 0 of the expected 1 records.", I know that this happens when the data is changed in between pulling it from the database and sending it back but, the database is not being edited.
View 6 RepliesNone of the "answers" that I have been able to find, address the problem. I am using oledb to read and update a MS Access DB in an ASP.NET application.I read the member dataset and fill it using the data adapter.I modify the row of data in the dataset.I then use the data adapter to update the row and get the error shown in the subject.
I am an experienced developer using ado.net on sql server windows application via the data adapter, so am familiar with how this should work.
I have searched everywhere and am hoping that someone here at Microsoft might have the answer.
I keep getting the above error when trying to update a record from a SQL Server DB TableWhat exactly does this Error Message mean?
View 3 Repliesthe problem here happends every time i tried to change a record that's been allready saved.Private Sub PropuestasBindingNavigatorSaveItem_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PropuestasBindingNavigatorSaveItem.Click
[Code]...
i have this delete code
My search
Public Sub mnamesearchdata()
'search data
Dim blnfound As Boolean
blnfound = False
[code]....
My Database In case. Having weird issues also were my database will be wiped out. Having 0 record.
[URL]
I am working on a program whereby insert, update and delete of database is required, i have been able to do so successfully but the above error occurs when i tried to insert a new row of data into the database and tried to edit it and update it to the database. The database platform i used is SQL server 2005 and i am using datagridview to display my data, my primary key is "s/n" which is an auto number, however, whenever after i insert data into the database, the newly added row has the "s/n" column blank shown in the datagridview and after i edited that row and tried to update it, the error occurs.
Imports System.Data
Imports System.Data.SqlClient
Imports System.Threading
Imports System.Text.RegularExpressions
[code]....
Im having a access violation error on my QueryPerformanceCounter Statement and im not sure why. I've search the internet for answers but found none.Declaration:
Private Declare Function QueryPerformanceFrequency Lib "kernel32" Alias "QueryPerformanceFrequency" (ByVal lpFrequency As Int64) As Boolean
Private Declare Function QueryPerformanceCounter Lib "kernel32" Alias
[code].....
with this code? Im getting a conurrency error when I try to update the access database:Concurrency error the delete command deleted zero of the expected records
View 7 RepliesI get an error when updating a related table, the main table can be updated but the related gives me a concurrency error but I don't know why. Btw I'm the only one using the program and it's connecting to sql server 2005 express.Inserting works like a charm.My piece of code, I hope you get it. The concurrency error is given on Me._objtblOrderinformatieA.Update(Me.objdtsOrders.orderInformatie)
If MessageBox.Show("Bent u zeker dat u deze record wilt wijzigen?", "Orderbeheer", MessageBoxButtons.YesNo) = 6 Then
update_dataset()
Me._objtblOrdersA.Update(Me.objdtsOrders.orders)
[code]....
I'm trying to call a Dll function which looks like this (in the C/C++ Dll):declspec(dllexport) void execute(char** ReturnMsg, char* serverAddress, char* commandLine)
The VB 'wrapper' function looks like:
<DllImport("TPClient.dll", EntryPoint:="execute", CallingConvention:=CallingConvention.Cdecl, CharSet:=CharSet.Auto, ExactSpelling:=True)> _
Public Shared Sub tg_execute(<Out()> <MarshalAs(UnmanagedType.LPStr)> ByRef returnString As System.Text.StringBuilder, _
[Code]...
I put a try/catch block around a bit of code that occasionaly throws an expected exception, but rather than catching it and displaying the message box, it stops the debugger and alerts me that the exception is unhandled.How do I handle this exception so my code doesn't stop when the exception occurs?
Friend myDevInfo As New devInfo
''' <summary>
''' Closes the device handle obtained with CreateFile and frees resources.
[code]....
I am using VS2010 release edition with Windows XP, Vista, 7
my programme works fine in XP but fails in Vista and 7.
All I am trying to do is open a OpenFileDialog to get a filename. [code]...
I'm been upgrading an application form VB6 to VB2008
I've started getting "Access Violation Exception was unhanded - Attempted to read or write protected memory" error message.
I am making a simple program that allows a user to add and delete contacts from a database. Whenever I try to delete a contact that was created in a previous session (by session, I mean time that I ran and then ended the program), it is fine, but when I try to delete a contact created in the same session, it says: "Concurrency violation: the DeleteCommand affected 0 of the expected 1 records." here is the code for the delete button: [code] I noticed that, since the error does not happen on a new session, that if I added the code that happens at the form_load, I could fix the issue.
View 2 RepliesI have exactly same problem as guy at [URL] . Quote: I'm using multithread in my application. in each thread, launch a form which has a webbrowser. each browser is controlled by another thread to test some sites. however, sometimes, it has some access violation exception. these exceptions are not beause of cross thread issue since all processing for the browser are using delegate. And the problem is: I can not catch the access violation exception.
View 3 Replieswin7 64bit, VB express 2010.
I'm working on a project. The main form is a MDI parent, it host a control form. on control form, there is a button. when click it, it will start, say 10, threads.
each thread will open a standard alone form (not mdi). on each form, it has a web browser control. when the form opened, it will start a new thread which makes the web browser control load a url, then depends on the links in that url, it will load another url, and loop for some times. then, the thread stops, and the form closes.
for some reasons, I got this weird exception:
AccessViolationException was unhandled by user code. Attempted to read or write protected memory. This is often an indication that other memory is corrupted.
1) the exception happens randomly, and not always happen. when it happens, it is always some code related with the web browser, i.e.
Not (MDIWebBrowser.ReadyState = WebBrowserReadyState.Complete)
or
MDIWebBrowser.Document.Body.InnerText()
2) I put a try catch in, but, it can not catch this exception. If I just close the exception dialog, sometimes, it keeps running without problems. sometimes, it just pauses the webbrowser control.
so, I did some research. it seems many people had the exact same problem. and it seems the best choice is:
[URL]
I checked all solutions suggested, even manually change the DEP, by using "bcdedit.exe /set {current} nx AlwaysOff"
but, the exception still pops up.
I have the following query that executes when my form loads. It's the rowsource for my combo box. The query is fine and populates the combo perfect, however, when i click into the combo box I cannot click out of it or even close the form. I have tried taking out the line of code that fills the form via table adapter on load and it works fine (opening the form unbound by the main table). Has anyone run into this before? I have another combo box on the form setup the exact same way and this is not happening. I've experimented with different datatypes etc....
code to populate combo box:
Public Shared Function LoadCallSource() As String
Dim sConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:Documents and Settingsdiw07My DocumentsDaily Backupsphone memo backend.mdb"
[code]....
If I take out the line
Me.MemoTableAdapter.Fill(Me.Table_Memo.Tables("Memo"), intMemoID)
The Combo boxes do not act up or "Lock"
I keep getting the following error in XP only (not Vista or Windows 7) Attempted to read or write protected memory. This is often an indication that other memory is corrupt The interesting thing is that the error is on a line that basically just creates a bitmap:
vb
Dim B as New Bitmap(400, 300)
This is in a timer and doesn't always happen the same time - eg sometimes it happens in 2 seconds sometimes it gets to 10 seconds - the interval is 50ms?