I have my client app installed in many computers, each computer is connected via LAN. Each Client app uses its own SQL database. I need to synchronize the databases in each computer so that every client app has the same data. How can I achieve this using VB.net (VS 2010 , Winforms)
View 1 RepliesI'm writing a desktop application that uses the main access database that will be hosted on a central server, but there will be a laptop with the app on that has an offline mode so records can be created offsite. When the laptop returns I want it needs to be synced back to the main database.
Has anybody got any pointers on a way to do this, I've briefly read about JRO but is there an alternative / better method?
Originally, I was just going to write some custom code to do this, but thought I'd check to make sure there wasn't something already out there.
how reliable is LastWriteTimeUtc to synchronize 2 folder on 2 different computers? what problems could rise using LastWriteTimeUtc.is there a better way to see if a generic file is of a newwer version?
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synchronizing a combobox with a textfield. I have a form with a textfield and a combobox. The combobox is populated with the department name from the database when the form loads. I would like the textbox to display the corresponding department number when the user selects a department name from the combobox. I have tried using the SelectedIndexChanged event of the combobox but I can't seem to code it to work. This is the code I'm trying to use but it is displaying "DEPARTMENT" in the textbox. Department Code is the primary key of the table.
strSQL = "SELECT * FROM DEPARTMENT"
Dim da = New OracleDataAdapter(strSQL, cn)
da.Fill(dSet, "DEPARTMENT" )
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I'm trying to get my application to restore the default values of my application settings but every time I click the Synchronize button it says:
No user.config files were found in any of the following locations.
I have never before tried to synchronize this application and am working with Visual Studio 2010. [URL].
I have a small application in ms access for student information. which is on my sever.now I have same application in .net and sql server which is online in my website, while access application is on my pc...Now I want that, If i make changes in my access application, the data must be copied to my online application automatically,Same thing i want vice versa,means if i make changes in my online application, the data must be copied to my desktop database.
View 1 RepliesPrivate Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
If ListBox1.Text = "kg" And ListBox2.Text = "lbs" Then
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I have two datagridview with same columns. When user resize the column of one of the datagridview during run time, then another datagridview column will synchronize to resize as well..
View 2 RepliesWith my program I wanted to change the fixed connection string to a User entered one. So in the application settings I added DBConnectionString as a user define String. If the string if empty, it shows the window where one can add the server, database and user name / password. If you press the OK button, it saves the settings:
Private Sub LDBOKBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LDBOKBtn.Click
' ----- Server name is required.
If (Trim(LDBServer.Text) = "") Then
MsgBox("The Server or Host name is required.", _
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The problem is that when you press the same button to show the System Settings again, the ConnectionString is empty again. So nothing was saved.
I have written a stupid backup utility that copies new or modified files. That's fantastic until I come across files that are 11 GB in size that have been modified. I have a feeling I can compare the file to be backed up and the file that will be over-written (old version of file) and "synchronize" the file instead of copying the entire 11 GB.
View 6 RepliesHow can i synchronize dragged controls (in my application), so they maintain their relative position to each other? is there some API function or .net method that can do this?
View 5 RepliesI have a class that contains a List(of T) used in a multithreaded application. I have three methods Get, Add and Remove where these access and modify the List(of T). I was using SyncLock to lock m_List any time I queried it for the desired object as well as when I added or removed objects. However I'm curious as to if there is a performance gain by simply locking m_List when I add an object or remove an object as opposed to when I'm searching for a desired object?
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I've got an XML file which is a pain to manually update. So I was thinking of creating a small app which synchronizes this data for me based on data from an Excel Sheet or something.
The XML schema looks like this:
<Data>
<Level1 value="Canada">
</Level1>
<Level1 value="Chile">
[code]....
I sometimes come across patterns or common practices that I do not agree with. I have a clear opinon of what is considered "good design", which is mainly based on my understanding of abstraction and creating layers.IMO, the core of an application is it's object model. It's a hierarchic model where one object references other objects or lists of them. That's a memory-internal model. For example, a house object references a list of rooms referencing lists of furniture.An object is identified by it's reference. There are no IDs or PKs in that layer.Saving/Loading data is an additional feature. Sure, no application will do without, but it's based on top of the core of the application. I could write an application that works very well without loading/saving, and for version 2 I will think about whether to save data to a database or an XML file. Merely this fact proves that a database layer is not the lowest. I've never agreed with that three-tier model - even if you call me unteachable.
In addition to all application objects, there are Datasets - and that's my problem now. They can be considered as a copy of what is already present in the application's object model. Its from a different, table-oriented view. As both structures exist in parallel, there's the need to synchronize the DataSet with the (rest of the) application's objects.That's the task that I am always struggling with, and I ask how you handle it. I know this is a major design question but, fortunatelly, I could quite get around this problem so far.The only solution I can imagine is maintaining additional relation lists. For example, whenever the property of a room object changes, that change must be reflected in the associated DataRow in the DataSet. For this purpose, I need a look-up table that tells me the PK of the given room in the database. It requires a lot of additional efforst to do all the synchronization.Again, the house or room object itself does not have a PK and it won't get one because on that layer, it doesn't even know that a database exists.
synconize scrolling of two webbrowser controls in VB?
View 2 RepliesI am using Mail.dll Commercial component. I can read the unseen or unread messages in my windows application. IF i open the mail using the [URL] then I cannot get the mail in windows application. Is there any way to synchronize the gmail mails
View 1 RepliesWe have a reporting app thats needs to update it's charts as the data gets written to it's corresponding table. (the report is based off just one table). Currently we just keep the last read sessionid + rowid (unique combo) in memory and a polling timer just does a select where rowid > what we have in memory (to get the latest rows added). Timer runs every second or so and the fast sql reader does it's job well. So far so good. However I feel this is not optimal because sometimes there are pauses in the data writes due to the process by design. (user clicking the pause button on the system that writes data). Meanwhile our timer keeps hitting the db and does not get any new rows. No errors or anything. How is this situation normally handled. The app that writes the data is separate from the reporting app. The 2 apps run on different machines. Bottomline : How to get data into a c# app as and when it is written into a sql server table without polling unnecessarily.
View 4 RepliesI have a multi-threaded application with several datasets that are read/written to from a couple threads. I have read that datasets can handle multiple readers and one writer. I have synclocks around all dataset writes and no synchronization around reads. I am experiencing random "Index was outside the bounds of the array." exceptions where a dataset item is in a conditional statement, for example:
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I have application in .net 2.0 in which I have a DataTable object globally in my application and have different dataviews in whole application.
When an action performed i have create many threads lets say 5 in which data is read from different dataview, meanwhile while 2/3 threads are reading data(not all 2 more left to read data) a thread write data in datatable. So we get exceptions like "Enumeration update" or "parameter not null" type.
I have use ReadWriteLock for this but do not find any luck it gets stop on ReaderWriterLock.AcquireWriterLock().
I have a windows application that need to process som quite time consuming jobs. In my first try i did all processing under
the form thread. The result was bad response and update of the form due to the heavy jobs.To get around the problem with bad response from the form i created a new class "processing" where i put all the data processing. Then i instanciated a background worker where i in the "doWork" sub created a new instance of "processing".The "processing" class creates a timer from system.timer, and the timer drives the processing.On the Timer event Elapsed the timer starts a new thread from the thread pool.
My problem is now when i want to asynchronously close the background worker (with the corresponding function call what ever it is called ...) there is still a timer thread out there that causes exceptions for me.
1. How can i close my background worker and at the same time have the timer to be stopped?
2. Is there a way to synchronize the timer event so that the timer executes from the background worker thread?
3. Is there a better approach for me to adapt?
I am working on a windows application project on NIST time synchronization, but can't get a proper solution for it. If anyone can send me the code to synchronize time from the global time server in VB.net or C # code
View 2 Replieshow to set my pc time application sync with my remote time server?...my pc application is 192.1.2.1 and my time server is 192.20.10.1...
View 1 Repliesi've been doing ADO.NET for a while but I would like to know if its posssible to use dao recordsets in VB.Net 2010 and where I can get tutorials and code samples to do database stuff like insert etc. I've tried to google but most of the code available is for vb6 I was going through some stuff on this link [URL]../bb243801%28v=office.12%29.aspx and i'd like to know if it works for vb.net 2010 or maybe theres something i'm missing. because the moment I put "Dim dbmyDB As dao.database" its been giving me the wavy blue line and i am now doubting if it works or maybe i'm missing some other code
View 1 RepliesIf you are using an sql database with a vb.net application, does the user need to have anything extra other than the .net framework installed for the program to run? Meaning, if I simply compile the application, are there any extra steps I need to take to make this work?
View 1 RepliesOk, so I am on my last book of course material for college and this weekend I started making my own personal applications, stuff I can really use in everyday life, these projects also serve as a port folio for future employers
View 1 RepliesI recently moved over to a Windows 7 computer and I can't get databases to work with VB.net.Before I moved I used to do an Access database and connect it to VB through the ODBC thing. However, I don't have Access on this computer (open office) so I'm not sure how to create a database and connect it.I have tried to use the SQL Compact Edition that comes with Visual Studio but I not sure how to get it to work. Also would something like mySQL work with VB? I have looked at the mySQL workbench and like it, what else would I need to download to be able to use the databases created with it in Visual Studio?
View 2 RepliesI am trying to carry out a synchronisation of two databases: one on the server and the other on a local machine. So that even when they are not connected on the network, the local database can carry on accepting data but when the network is back on, the local database can update the server and the server can also update the local machine with data it accepted during the time when the network was off. by first comparing two tables in two databases and then if they are any differences the updating begins and i've since been stuck.
Private Sub btnCompareTables_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnCompareTables.Click
'dont know which arguments to put when calling this function
'How do i tell the computer which databases to compare
Comparing()
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I have two dataset , each with with table . each datasets is connected to a separate dataadapter to get data from sql server database file (two different tables SQLtableOrders & SQLtableCustomerA))
datasetOrders.Tables("Orders") >>> the first column "orderID" is a primary unique key. Its structure is details below :
OrderID----OrderName----OrderCost--------Date
1----------A---------------54------------11/11/2010
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note that I had already made this by getting the data by SQL Statement "Select SQLtableOrders.* , SQLtableCustomerA.orderID FROM SQLtableOrders, SQLtableCustomerA WHERE SQLtableOrders.orderID = SQLtableCustomerA.orderID" It is really working fine , but the problem that it takes time to get data from the SQL server each time I disply orders. I already have the datasetOrders.Tables("Orders") data on the client PC , I need only to make the client PC extract which orders are assinged to a ceratin customers. I can do it by For... Next , but I guess it will take time , specially if "orders" data contains many data .
What control(s) do I need to use and how do I use them? I am ,looking for tutorials and sample code too.
I'm working on a trivia game where the admin can remove and add questions to a database. [code]...
I am fairly new to programming, and even more new to using database objects. I am creating a program that will calculate a user's BMI, and that will let the user know how many calories are in a food that they choose. I found a database that has a bunch of foods, and each of their calories, so I am using that. I have the program set up so that the user selects each food from a drop down list. The user then adds each of the food to a list box after pressing a button. The program is then suppose to calculate all of the calories after the user presses another button to come up with the total calories. I got all the foods on the drop down list no problem, but now, I'm stuck on figuring out how to get the program to add all the calories for each cooresponding food. I have no idea where to start with it. I know that I'm going to have to create a variable to hold the total calories, but I just don't know how to get the calories from each food.
View 8 Replies