I'm using the following code to update a SQL CE database:
VB.NET
Public Sub SaveOldEntry(ByVal duration As String, ByVal checkinDate As String, ByVal receivedBy As String, ByVal platformName As String, ByVal serviceTag As String, ByVal
[code].....
I would like to know the best, or standard, way to accomplish real-time client updates in a small multi-user application using an access data table as a data source.Specifically, this application will be used by 3-4 people. It uses a datatable which is filled on form load and bound to a datagrid at design time. The datatable is stored on a shared drive. The data table on the shared drive is updated in two ways:
1) Users can update the datagrid which then updates the datatable on the shared drive via the data adapter's Update method.
2) A server application does some work on some text files, periodically updating the data table.
I need the clients to reflect the changes to the data table on the shared drive as closely to real-time as possible. I know that the data table stored in memory on the client is disconnected from the data table on the shared drive, so I must query again to get the updates.
1) Is there an alternvative model I can use which is connected, and which will automatically reflect the updates in the data table on the shared drive?
2) If not, what is the best way to check for changes in the data table (so I can know when to call the data adapter fill method)? I am planning to poll the drive for a change to the .mdb file, raise an event and then fill the data adapter when the event is triggered. I am using this method successfully now to check for changes to a text file in another application, and I know how to implement it?
I would like to know the best, or standard, way to accomplish real-time client updates in a small multi-user application using an access data table as a data source.
Specifically, this application will be used by 3-4 people. It uses a datatable which is filled on form load and bound to a datagrid at design time. The datatable is stored on a shared drive. The data table on the shared drive is updated in two ways:
1) Users can update the datagrid which then updates the datatable on the shared drive via the data adapter's Update method.
2) A server application does some work on some text files, periodically updating the data table.
I need the clients to reflect the changes to the data table on the shared drive as closely to real-time as possible. I know that the data table stored in memory on the client is disconnected from the data table on the shared drive, so I must query again to get the updates.
I have two questions:
1) Is there an alternvative model I can use which is connected, and which will automatically reflect the updates in the data table on the shared drive?
2) If not, what is the best way to check for changes in the data table (so I can know when to call the data adapter fill method)? I am planning to poll the drive for a change to the .mdb file, raise an event and then fill the data adapter when the event is triggered. I am using this method successfully now to check for changes to a text file in another application, and I know how to implement it
I've seen similar problems posted on this and other boards, typically with a bunch of code checking before its realised that that database itself is being copied to another directory and run from there. Apparently this is managed via the database properties, copy to output directory settings. In my case I have tried all three options, with no change in result. After "saving", inspection of the actual database via the server explorer shows no changes have actually been committed.
I am getting to a point where I need to start entering large amounts of data into the app and have at actually save to the db for deeper testing.
I noticed this behavious first when using an .accdb and it has persisted through my exploration of SQL(.mdf)
db Output Option Selected / Result
always copy... data changes do not persist between debug runs and is not entered into actual database
copy if newer... data changes do persist between debug runs but is not entered into actual database (checked via server explorer)
Do Not Copy... generates the below Error on execution
System.Data.SqlClient.SqlException was unhandled
Message=An attempt to attach an auto-named database for file C:UsersXXXDesktopVisual Basic ProjectsSQLtestWindowsApplication4 - CopyWindowsApplication4inDebugMyDatabase.mdf failed. A database with the same name exists, or specified file cannot be opened, or it is located on UNC share.
Basically I want to be able to save any data I enter into my data grid / dataset ermanently , so when i close the program or restart it the data I previously entered within the grid will be present.This is what I have so far
BindingContext(CustomersDs, "Customers").EndCurrentEdit()
OleDbDataAdapter1.Update(CustomersDs) is called Shop.mdb )
[code].....
I have Data coming in through a serial port and it consists of pretty much all numerical values except for a few begining response characters. Its a Load Cell which spits out Tension in Pounds. I'm making a simple terminal program with the ability to log the Incoming Data for record keeping and data plotting. I want the incoming Tension to be displayed on the screen real time.I can get it into a text box and have it scroll indefinetly as it updates the data,but I'd like to keep it localized in one Label. I can display it in the Label but it wants to scroll down as it comes in. I want to keep it refreshed in one spot if that makes any sense. Heres what I have thus far. It will put it in the Label but wants to scroll like in the textbox. For example if I send #00F0 followed by a carriage return it replys back with whatever is displayed on the Screen which usually is the tension.it says "01TK 00.074 LBS" no quotes.. for a reply.I'm assuming it needs to be stripped down to just the numeric characters first.'here is what gets sent to the Load Cell to tell it to output data fast as it can to the serial port.[code]
View 5 RepliesI have a datagridview and the datasource is a database query. This query takes data from multiple tables within the database.
When I run the project the data loads to the datagridview fine. However, the system needs to allow the user to update data shown in the datagrid and save it.
I've been messing with this for ages now and it is still not saving correctly. Here is the code behind the save button:
Private Sub btnSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
Dim strUpdate As String = "Update tblAttendance set Reasonforabsence = @Reason For Absence"
[Code]....
ToTable.AcceptChanges()
If TypeOf Adapter Is OleDb.OleDbDataAdapter Then
CommandBuilder = New OleDb.OleDbCommandBuilder(Adapter)
[code].....
In my form i have a datagrid view and two textbox the textbox is bind with the datagrid..now when i click the data in the datagrid the data will go to the textbox (that's i want to happen) but when i click the update button and check my database it doesn't change.. i use ExecuteNonQuery to update my data.[code]...
View 11 RepliesI have a form with many controls that are binded to a datasource. when some of these values change, they impact aspects of the form itself like the backgroud color or the title. There is a filter applied to it so it only displays certain records (this is important).when I change something and save the data I need to update the filter to show all the previous records plus the current one.All that works great, but the problem is: saving the data or changing the filter makes the controls take a new value based on the new record and go through the subs that each one have to modify the aspect of the form. This happens because if I save the data first, then the current record does not conform to the filter and all the data in the form changes, or if I change the filter first, we go to the first record of the set.
After that I return to the correct record and everything looks fine, but going to all the changes makes the app halt for a moment.Is there a way that I can stop the controls in the form form updating to their binding data while saving or changing the filter in the bindingsource?
I'm sure im just making a simple mistake some place but i just cant find it. I have datatable which I can and can make changes, save back to the database just fine. But if I reload the data after updating, no data is retrieved from the database. But if I stop debugging completely and then start again, it loads just fine...until i call Update.
Here is some code I am using for testing purposes.
Private myDataSet As New DataSet
Private conn As MySqlClient.MySqlConnection
Dim myDataAdapter As New MySqlClient.MySqlDataAdapter
[Code]....
when im updating my data through a textbox and i save it, i dont automatically show the updated file on the datagrid, here is my code btw, i already tried some code but it aint working
[Code]......
How do I updatezz data from 2 rows to 2 columns?
tool: vb.net
server: MySQL (SQLyog)
I have 2 tables, membercardlist and memberinfo:
table membercardlist:
------------- ------------ ------------
| AccountNo | CardNo | status |
------------- ------------ ------------
| 9999 | B009 | inactive |
[Code]......
Honestly I do not understand why I need to write code to update a databse and why it stores it localy. I'd simply rather the system update the individual row after it is scrolled off of.
In either case since I guess I can't do that.
Here is some code in a button on a form
Try
ItemsTableAdapter.Update(NewCreationsDataSet1.Items)
LineCodeTableAdapter.Update(NewCreationsDataSet1.LineCode)
Catch ex As Exception
[Code].....
I'm Using vb 2008 and an access DB.I have 2 tables in the DB which is transaction and products.When a Customer Buy product the transaction will record and the stock of that product will deduct accdg to the quantity bought by the customer. Myproblem is products table didn't update. Stock of that product still didn't change.
View 5 RepliesI am trying to update a table based on row selected in a grid (C1TrueDBGrid1.Columns(1).Value), but I am getting the following error:
Update unable to find TableMapping['Table'] or Data Table 'Table'
Code:
Dim ConnectionString As String = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=/DataDirectory/AOPT2002org.mdb;Persist Security Info=True;Jet OLEDB:Database Password=testaopupdate" Dim objConnection As New
[Code]....
I have one DataSet and two forms, Customers and Efficiency. When I make changes to the Customers table (Delete a Customer for instance) It does not reflect the changes on the Efficiency table. The default form is Efficiency and I'm calling the Customers form from within the Efficiency form. I make the change in the Customer form, I then close the Customer form and call the Efficiency form back. The data is not updated on the Efficiency side until I close the application and re-open it. what code I need and where to inject this code?
View 14 RepliesI have a class which I'm binding to a series of textboxes, date pickers and so on. When I change text in the text boxes, the object updates just fine, and when I then save the data, it has the changes. My problem seems to be with the RTB ... if I bind to the .Text property, it works just fine and updates like any normal text box. However... when I bind to the RTF property... changes to the object don't happen unless I first click out of the RTB... quite annoying. If I edit the text or change the formatting, and hit the save button, the changes don't get reflected in my object. I've even tried using debug statements to track when the property is changed, and I'm not getting the results I desire.
View 7 RepliesI am working on a project that stores data on animals. I am trying to make updates to data already stored there, through inputs on a VB form. A form where all the data is populating the fields shows up and the user can change/update any field. Once they are finished, they click update and the DB is supposed to reflect those changes (Theoretically)However, I wrote the code to do that, but when it runs nothing in the database is changed and nothing gets done, as it seems. No errors appear and nothing goes wrong with the program. It just doesnt change the data in the db.
View 1 RepliesI am working on a project that stores data on animals. I am trying to make updates to data already stored there, through inputs on a VB form. A form where all the data is populating the fields shows up and the user can change/update any field. Once they are finished, they click update and the DB is supposed to reflect those changes (Theoretically)
However, I wrote the code to do that, but when it runs nothing in the database is changed and nothing gets done, as it seems. No errors appear and nothing goes wrong with the program. It just doesnt change the data in the db.
Here is the code updating the database.
If txtNewID.Text = "" Or cmbRegion.Text = "" Or txtWombatName.Text = "" Or cmbGender.Text = "" Or txtAge.Text = "" Or txtWeight.Text = "" Or txtLength.Text = "" Or txtCommunity.Text = "" Or txtDescription.Text = "" Then
MsgBox("Please fill in all required fields.", , "ERROR")
Else
[code]....
I have two forms in my program, Form1 has ListBox which contains names from the Database.Form2, has textbox and add button to get a new name from the user.but when I click on add button.. i return to Form1 to view the names in the listbox by clicking on view button: ALL NAMES ARE DISPLAYED WITHOUT THE NEW NAME.when I close my program and click on View button all names including the new name that was entered before are displayed ! is there a way to display everything in the database without closing the program??I need a way to refresh or something.
Form1:
Imports System.Data.OleDb
Public Class Form1
Dim ds As New DataSet()
[code]....
I have a datagridview and 3 buttons (New, update and delete).When I enter the form and I make changes to the datagridview and I save them, everything works fine.After the first save I make some more changes and I hit save again I get the error:"system.data.dbconcurrencyexception concurrency violation the updatecommand affected 0 of the expected 1 records"
The code I use below:
Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
Me.dgvOrderRegel.AllowUserToAddRows = True
[code]....
I'm wondering, is there a way to update databases of a windows application that is distributed on several computers all at the same time? is it done by using sql server? because I'm developing an examination system that will be distributed on several computers for students to take exams and I'm just wondering if an admin updates a questions database will the changes be applied to all other computers as well or should it be done manually? sorry if I sound stupid but I can't seem to understand this part of my work, I was thinking about switching to a web app since it seems easier, but again this data updating issue is giving me hard time. by the way I might link the application to an internal network, will this have anything to do with updating the databases?
View 1 RepliesI can't seem to save data in the database when updating a record. The record appears to be updated and even displays the new record on my form but as soon as I close and restart the program the old record is back and no changes are made to the database. Is there something im missing here ?
If CN2.State = ConnectionState.Open Then
Dim Comand As New SqlCeCommand("SELECT * From Incentives Where IncentiveCode = '" & TxtCode.Text & "'", CN2)
Dim rs As SqlCeResultSet
rs = Comand.ExecuteResultSet(ResultSetOptions.Sensitive + ResultSetOptions.Updatable)
If rs.Read Then
[Code]...
I have a form that lists all of the clients in a DataGridView and when I click on a column that is a Link I want the data to populate into the form I use to capture. My problem is that when I click on the link all the TextBoxes on the form are filled correctly but my ComboBoxes are not.[code]
View 1 RepliesThis is the form I'm having problems with. As you can see I've created a tab interface which is working. There are five text boxes on it which are binded to the Staff table in the database. When the tab is changed, the binding is changed to a new field. However, unfortunately, when a new record is selected, the data bindings do not update, and instead, the first record is always being used. We suspect the problem may be coming from the fact that there is code to unbind from the text box and rebind it again. This is the code I'm talking about...
Private Sub TabCheck()
If TabState = 1 Then
pnlTabs.BackgroundImage = My.Resources.tabs1
txtBox1.Visible = True
txtBox2.Visible = True
[Code] .....
I am writing a simple app using Visual Basic 2008 Pro, and SQL Server 2005 as the backend. However, I copied the database file (.mdf) from another computer onto my laptop. I added it as a Data Source by having the Data Provider as "Microsoft SQL Server Database File" and have it attach the file to the local SQL server. However, it isn't set to copy the database to the output directory every time the program is run for debugging, as I thought that would save time.
Now however, the data update to the database are very wierd. I run the program, add some new data, save it, and it returns the new primary keys properly (that is, it turns from -1 to 4 or 5 or whatever, indicating that the data has been saved). When I close and re-run the application to check that the data has indeed been saved, it reflects the changes and shows me the new data. However, when the program is run again after some time, the changes I made are gone. I'm assuming this is due to some wierd way in which VB is updating the database that temporarily updates its cached or copied database, but doesn't actually change the real database. How do I fix this? I had previously done the same project on another computer, except there the data source was directly the local SQL server, and I had created the database directly on the server through Visual Studio itself, and I didn't face those problems then. Is there any way to manually attach the SQL Server database file (.mdf) to the local SQL server instance permanently, and change the app to use the attached database instead?
I have a storedProcedure that populates a dataset, this dataset is then used for a dataSource for a third party grid control. This all works fine, however I am having real trouble in updating the dataSet with the most recent data from my database.Below is the code that I am using to populate the dataSet:
[code]...
I am not sure how to update the dataSet with new data so that my grid control displays the most recent data. Could someone show me the code to do this?
My form just isn't updating the row in the database: Here's my code:
Protected Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
If Request.QueryString("a") = "edit" Then
Dim CategoryText As String = lstCategory.SelectedItem.Text
Dim conn As New SqlConnection("Data Source=.SQLEXPRESS; Initial Catalog=LogansArchive; Integrated Security=True;")
[Code] .....
I've never used nested SELECTs in SQL before so I'm not sure if I did it right. Aside from that, this is all stuff I've done before so I'm relatively sure that it's all correct. Finally, there are no errors being reported when I debug, although the updates don't seem to be coming through from the text fields (txtContent.Text isn't changing to reflect the new value).
I am a bit of a newbie when it comes to vb.net and databases and I have a small favor to ask anyone I am looking for a very basic example on how to connect, read, update and insert data into remote mysql database. I have successfully connected to my database with the code below,, and for the moment I am just trying to LIST data from it in a listview control,, and then would like to find a way to insert data into it and update data.
Al examples I find on the net are too long and usually have too many unnecessary data around the code I need so I get a bit lost in it.Can anyone point me in the direction of SIMPLE examples that are easy to follow or provide a bit of useful code I could learn form.
[Code]...