DB/Reporting :: Updating Client Data Tables When Data Table On Shared Drive Is Updated?
Sep 28, 2009
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 am currently working on a Database that collects information. Firstly, i use a new windows form to collect that data. I have it set up to where, when the form loads, the database is ready to collect the information fields. And then the form closes on the button click to add that data, it does not update that data table view. It adds it once i close the program and debug it again.
Code: (Open the windows form) Private Sub btnAddNew_Click_1(sender As System.Object, e As System.EventArgs) Handles btnAddNew.Click AddNewClientData.ShowDialog()
[Code].....
Problem two: I need to make a button that will increment a cell that was set as an Int, by one, but can't figure out how to put it into code.
I have an issue with a data table that I have updated using the datatable.update command.The datatable is bound to the datagridview using dgv.datasource = datatable.I have used INSERT and UPDATE commands and the INSERT command writes the data back to the database ok. However my problem is that it the dgv is not updated with the primary key (ID field) from the database. So when I save a second time, instead of updating it just inserts the data again.
I have an Access database that is updated directly in Access. I'm trying to write a program to 'monitor' the database, and have a DataGridView control showing the contents. When the program is first started, it shows the current data in the DB fine, however, I've been unable to get it to refresh with any updated data from the mdb file. I have a timer running on 5 second intervals, and if i clear the dataset, the DataGridView refreshes to empty.
if it affects the run time of a program if I were to have multiple data tables as opposed to one data table with all my data in it? I am trying to minimize datagrids and just use code to access table data, in hopes that it will speed up my program. But I am ignorant if multiple tables vs 1 main table will make a difference because there will still be the same amount of overall data present in my program one way or the other....?
I found something very strange, in the data base explorer I modify the conection to the location of the data base(F:My DocumentsMy ResepteResepte.sdf) , but after raning the app. the path is back to what it was in the project folder and so the same in the selution window. It is set to Do Not Copy. How can I change this so that the IDE looks at the propper data all the time.
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.
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?
I am currently using vb 2008 and access 2003 as back end database. I am trying to import excel data to a data table. my excel and access table header & columns are same. I was trying to do this.........
I am getting an incorrect repsonse after an update to a table. In my RowUpdating event I have the following code which builds an Update Parameter to call an SP to update a table. I must be doing something wrong but everything runs fine. My rowsAffected variable reports 1 after the update, but the table never gets the data.[code]I found a solution that is working. On the original DataSource for the update command I needed to add the following.[code]This in essence allows the original data source to call the SP. Note: that the command type needs to stay as TEXT not Stored Procedure as one might think.
since I still use VB6 and the code is in VB8, I can't find the solution.The sub below is executed in a button's click event, and is supposed to save data to his database. It seems to work fine : you can add persons (in a separate form), and see them appear in the datagrid. You can stop the program, go back to the VB editor, and run it again (without rebuild), and the previously added persons will still be visible in the datagrid. But...If you add some persons, then go to the editor and force a rebuild (for example by adding more code), and than run the code again, the the previously added persons are gone (nomore visible in datagrid)!To me, it seems that the problem is to effectively update the database. I have searched on the internet about this topic, and I read that you must "set" the UpdateCommand.
I want to make relationship between them Where In the F column of Table2 will sum the numbers in F column of table 3 according this condition ( show in the pic.)For the same data in columns(B,C,D) between two tables Example: Table 2 include in B,C,D data HH XX FF There are many data (HH XX FF) in tables3 in same columns(b,c,d) so it will sum the numbers in F column that in the same row with the data (HH xx FF), and insertded the results in the in table2 in F colmn in the same row with (HH XX FF)
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?
When I am trying to connect to database from VB.net, I am getting error. This is my code. Public g_Conn As new SqlClient.SqlConnection With g_Conn .ConnectionString = "user id=sa ;data source= CCTSRV8; " & _ "persist security info=True; " & _ "initial catalog=pubs ;password=mrwizard" .Open() End With I am getting system.data.sqlclient.sqlclientpermission error.
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
I would expect to see the path.Path include the new record, however, I also notice that tempnextgen also include the new record. Can anyone help me out on this issue? Why the tempnextgen got updated as well, how to prevent this unexpected operation?
how to compare 2 sql tables and show data that are in table 1 but not in table2?
Dim strSQLL As String = "Select t1.run from ML533 t1 left join portal t2 on t1.[run] = t2.[runNo] where t1.[run] <> t2.[runNo]" Dim comm As New System.Data.SqlClient.SqlCommand(strSQLL, conn) Dim ds1 As DataSet = New DataSet()
[code]....
i have tried google and other sites.. but still cannot find solution. maybe i post the wrong question. but i manage to do this code. but its only shows only 1 record missing, but its supposed to show 5 records that r missing.
I have created a database in VB2008.NET using SQL 2008.
My problem is that while I am in the form where I see the the data, I want to retrieve backwards the related data from Owner and Car eg. the owners name and the car model.
I am combining data from multiple tables into one table for a presentation software. I am doing a select statement and running a loop. Inside that loop I have multiple selects and I build a datatable an enter the data into the main table. There is a ton of records and it takes forever.
'Requisition Demands InsertStr = "SELECT COUNT(*) FROM Requisition WHERE (DMD_DT = " & dateVal & ") AND (QTY_REQ > QTY_PEND_CANC + QTY_CANC + QTY_REJT) " & searchvalString
I'm trying to remember how to insert data in to a table. Here is my code
Code:
I get the error
Quote:
Number of query values and destination fields are not the same.
I also get some error about the Insert INTO part not being right somewhere. Am I doing this how you would do it, or how would you do something like this?
I have an access database with 3 tables, want to collect data from 2 and insert them into a new row in the third (although this seems redundant there are reasons for wanting it that way). I created a form and call the data from the two tables fine, once the form is filled I try to add a new row to the third but it will not add the row even though it is telling me that is has. When I open my access table the record is not there. I am new at this and just can't figure out why it won't work, I have tried several approaches the latest is
Code: Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Me.Activate() Dim IDNUM As String = InputBox("Enter Student ID Number") 'storing the text entered in a string [Code] .....
I have 3 tables. customer,item, pricing, each with keys customerid,itemid,priceid. pricing is related to customer and item tables by a 1 to many.pricing (priceid,customerid,itemid,price)
I am an old VB2 programmer and in the process of moving up. In VB2 I could obtain a data row via and index on an access table. I can not find an example on how to do this. I can retrieve a single row using a query, but an index would be faster. I know in Oracle use can use a hirt to direct the query to use the index.Here is what I was during in VB2 (Sample) with no hint.
Set Stock_Tbl = "DataBaseName".openTable(Stock_Tbl_Name) Stock_Tbl.Index="Symbol_Idx" Stock.Tbl.Seek="MSFT"
UPDATED: Here is the SP, it doesn't match exactly because of ongoing testing, but you get the jist. Some fields are commented out because of testing...
Using; - vb2008 Express, data on ACCESS 2003, objective; - to update a separate table not on the original query.From what i have gathered i need to add a second table adapter to make the changes to a related field in another table. Since i already have the 1st table adapter the second does not appear as easy as the second (dragn the data set over).
So i suppose i need to create the second table adapters programmatically? [URL]..I see that because they are not nested they need to each be declared.. right? If so that is where my issue lies. I'm having a problem with how to declare them both now that there must be two.
I am getting a System.Data.InvalidConstraintException" ForeignKeyConstraint CompanyPasswords requires the child key values(-1) to exist in the parent Table. When saving updates to the parent and child tables.My parent table consists of 3 columnsCompanyID (auto increment, pk)Company NameURLMy Child table consists of 4 columns PasswordID (auto increment, pk)CompanyID (fk)User NamePasswordHere is all the code on the form
