I am developing an desktop application using vb.net. I have an doubt, can update or sync database which are at different place. Means changes done at one place should get updated in other.
View 12 RepliesI am considering a piece of code that will manage access to a collection object from multiple threads - add, update, remove, clear. OK ... so I have put a sync lock within each method, but what is not clear from the MS documentation is exactly how the sync lock is behaving. Is it locking the piece of code it wraps? Or is it locking the object? And if it is locking the object a private static object should lock out any code locked on the object within all instances of the object? i.e. if an add operation is underway, an update, delete or clear will wait for the lock to be released.
Finally, if I have multiple threads contending for the sync lock, how is the release managed? First come, first serve? random (from my p.o.v)? Is there a chance that two separate threads could blunder into 'locked' code simulataneously?
I'm posting this in the vb.net as I will be using visual studio to perform the task. So here is what I am trying to achieve or at least achieve it more efficiently than what I am doing now.
So I have two identical database setups, both with a table , let call it table tblUsers. The local database is edited through vb.net and is a Access database. The second database is hosted on a remote server and is a MySQL databse.
Currently I have no problem connecting and editing either database through vb.net. I'm using OLE DB to connect and handle the Access database and ODBC 5.1 to connect and handle the MySQL database.
Here is what I would like to do:
User opens the program Presses the "update local" button
The program updates the local database to whatever the remote database is The user uses the program to edit fields in the local database
When done, the user presses the "Update remote" button and the remote database fields that have been edited with the program in the local database will be updated to the remote database.
Currently, the only way for me to do this is to go line by line in a for next and use a command builder to compare each field and update that way.
I was creating an enrollment system for my Thesis, and my adviser told me that I must have a Code in my program that Synchronize database from client and server so that if the terminal connection is "Up" the data will go to the server and if the connection is "Down" the data will go to the installed server on the the local machine. and every 20 mins or 30 mins will sync the database.
View 5 RepliesI want to filter the SQL Compact Database to get rows that as been synchronized to the SQL SEVER Using sync framework can any one give me an hint on how to get this done. I will prefer a sample code in VB.NET
View 1 Repliesso i got a program that i wanna derive in. like this:you right in this x^4+x^2-4x+8 and then the program will derive it to 4x^3+2x-4..how do i do that? like this x^4+x^2-4x+8 and then doing this 4x^4-1+2x^2-1-4x-x+8-8..how do i find the places to add and then drawing -1 to the right places?
View 3 RepliesI am working on a program using VB.Net 2010 which will enable me to setup groups of files & folders for back up with syncing capabilities etc. I have a concept program which is based on some sample code I found out in one of the VB.Net forums. I have modified it from a command line based program to a form based program. At the moment I consider this code to be a "concept" program which once I have the various copy/sync routines developed and debugged will be integrated in to another program I wrote for
creating "Back Up" groups to automate the process. There are some 3rd party programs that do similar things that I want to do such as Microsofts Sync Toy, but none of them offer the grouping and exclusions options that I am going to program in to this backup/sync program.
So here is my problem, I have the included code taking two folders, a source and a destination, and copying everything from the source to the destination. It will skip over any unchanged files/folders and will delete anything found in the destination folder that is not found in the source folder and it will update all files in the destination folder that have a newer version in the source folder. In other words it will mirror image the source to the destination but will be smart enough not to copy unchanged items from the source to the destination thereby saving a lot of time. The sync part of the program is working fine, the displaying of the progress and results is not.
[Code]...
Problem: Using the sub routing below, when adding a value to another value the results eventually change from 2-decimal places to multiple decimal places.Basically, the amount stored should always only be 2 decimal places, because the values passed in are always 2 decimal places. Output from calling the sub routine multiple times.
Running total = 329430.75
New Withheld Amount = 710.79
Running total = 330141.54
[code]....
As a workaround, I have a new routine that uses a custom round function to properly store only 2 decimal places - as the VB round function does not perform the type of rounding desired.I understand that we are removing the value from the dictionary and adding it back..
I am fresher in vb.net but I have experience in vb 6.0. But I want to connect database in sql server through sql connection. In that case how to create connection with window or sqlserver authintication mode and how to add or update new record in data base in batch transaction. Please help me with sample code.
So that I can understand eassily.
update statement, i am trying to update a row within a access 2007 database here is my code.
[Code]...
I am using vb.net with access database. I am using sql. How can i update database with the value 40'6"(Feet and inches values)
View 5 RepliesWhat is wrong with this code. It does not update the access database and no error.
Dim conn As New OleDbConnection
Dim sqlQRY As String = "SELECT * FROM StdMaster WHERE StuNo = " & txtStudentNo.Text & " ORDER BY StuNo"
[CODE]...
is there a way to update a database row with the update command by first defining all parameters and then all values just like you can in the insert command? "insert into table1 (parameter1,parameter2,....) values (value1, value2,....)"something like "set table1 (parameter1, parameter2) values (value1,value 2,...) where ...."?because I only know the syntax to define each parameters value "set table parameter1=value, parameter2=value2... where"
View 8 RepliesThis program is very difficult for me, but I must get threw it or I cannot finish... What I am doing is making a Database of foreign Languages with the spelling of the words and the pronounciation inside the database... The USER enters a paragraph of words into the translator textbox and pushed translate. The program has a DATABANK of words with the phonetic spellings and matches the word, then translates to phonetics. The problem is that new words keep appearing inside the language. So I incorporated a Database of 2 fields
[Code]...
I created a dataset and i am using OleDbDataAdapter to insert new values to access database. But when i close the program and after open it, values are not in the database. How can i solve this problem? Also, i have another problem. When i write codes that
[Code]...
i want to update my inventory table in database from another database name. Example: In VB, i had a form named Orderform. User need to select e product that they want and key in the quantity. all these information are able to store inside my database named ORDERTAB. but now the problem is i wanted to update another field in my database named INVENTORY by minus the quantity tat the user had key previously. i totally had no idea how it going to works.
View 3 RepliesI have a windows application and a php web application(not connected to internet all times), eventually data add/remove/update can happen at either places. So data has to be synchronized every day or manually.
I have a small sqllite database file (less than 500K) in my end, and the php web app uses Mysql, the structures remain the same. I would like to have a update function in my windows app, which sends my sqllite database file directly to my webserver and then1. Php should read values from the sqllite database files insert some values into mysql from the uploaded file 2. Php should read values from the mysql database files and insert them to sqllite database file
and finally send them back to my windows client pc. I would like to use .net 2.0.Anyone has an idea to get the above done or a suggestion to make the sync easier will help me a lot. Give me light on how the architecture or design should be done to achieve this
I have a class that sends an email which i use sendasyc
SMTPServer.SendAsync(message, _message_id)
The result of the email is captured by the following code
Sub SendCompletedCallback(ByVal sender As Object, ByVal e As AsyncCompletedEventArgs)
Dim message_id As String = CType(e.UserState, String)
[Code]....
This works fine when the code is run within a form but when i move it into a dll calling it from a console app it neither sends emails nor picks up any errors.
Public Class Form1
Public elapsed_time As TimeSpan
Public start_time, stop_time As DateTime
Public txtBreak As String = "180"
[code]....
All the code needs to be controled by seperate timers as the user may need to pause timer3 or timer4 at any one time. The problem I have is that after about 5 minutes the time and elapsed time are about three seconds ahead of the two count down timers.
I'm just looking for an answer or idea.I plan to connect vb.net to mysql (which is done) and also the PHP connected to the mysql.But I'm confuse with something.VB.NET is use for offline things (which people will come to store and buy), but PHP is buying / booking online. (You know the airport things right ? customer can directly go to the airport and buy tickets or they can buy tickets from the internet)
For ex :Customer A come to airport and buy a ticket which is only left 1 tickets. Customer B wanted to buy from the internet. Both of them saw there is only left 1 tickets. So, both of them buying. When Customer A buy, the employee click buy at the same time with Customer B.In here, I'm confuse, how to declare which person should get the ticket because they click buy at the same time (server time because PHP and MySQL located to the server and vb.net applciation located to other PC/Machine) ?.
I have two comboboxes on my form and both are bound to the same datatable. The problem is that each time a value is selected from one combobox, the value in the other combobox changes to the value selected in the former. Is there anyway to disable this behaviour?Only performance counts!
View 2 RepliesOn my form I have a button that says "Sync To USB" When its clicked this is what I want to happen: The files in ListBox3 will be copied onto a USB Mass Storage Device (if it is inserted) otherwise it will play the sound "USB not inserted.WMV".
View 5 Repliesi just want to ask if how can i sync my files (like dropbox) via web service? is that possible in vb.net?
View 2 RepliesHow can I sync 2 binding sources, both binding sources contain the same data(contactsbindingsource)I have 2 forms:1 form is a list of contact information the other is a search form.I have a linq querie in the search form that returns contact names to a datagridview, but I want to be able to double click on selected cell and have the relevant data appear on my first form.Also my first form has FK relationship to another form that contains company information, could this have something to do with it?
View 6 RepliesI am reading a lot in this forum about sync. It must be fantastic. I look a round for any tutorial, but I haven't found one. Let me tell me the story about the new program I want to write.I am working on a campsite in France. When there is a problem like a Mobilehome isn't clean. The person who is working on the reception write a note and the one how is going to fix it will be called. This is not a really good thing.I like to write an program in Visual Basic that allow the person who is working at the reception write the task in an program. This program will use a database to store the task. The person who is working at the campsite will see the task at his mobile phone (Windows mobile 6) He will fix the task and the reception can see in the application that the task is done.So I need a database who is synchronized whit the one in the mobile phone. The mobile phone can work offline and online. By online the database will be synchronized to the one in the reception.
View 1 RepliesI have a small "Clinic Application" that runs on two machines. (Receptionists & Doctors)
Same application is installed at both the computers, and they access the same SQL Server 2008 Data at a 3rd macine.
When the application is started, the local datasets are filled with the data from the 3rd machine (using tableadapter.fill).
Whenever the Receptionist adds a Patient in DataGrid,and saved it, it should show in Doctors DataGrid. and whenever Doctor adds something, the receptionists dataGrid should show it.
to accomplish this I have set a timer that keeps Filling datasets.
the task is successfully accomplished, but....
I have a new requirement to sync a DVR to an NTP server, but not sure how. I have googled and forum searched, but a lot is VB6 stuff and also for sync'ing a local computer's time. This requirement is for sync'ing time for a Digital Video Recorder on the network.
View 10 RepliesI have been using vb.net for a while. I am trying to figure out if there is a way that i can update file in a given folder to ftp and get any file on server back using vb.net?
View 2 Repliesi'm interested in syncing a remote folder and a local one over FTP but I don't want to use 3rd party components since this is not going to be a public build so I see no reason to invest on something like this now any code snippets or so available? PS. remote folder includes folders also that can change so I want to keep an update of the remote folder on my PC.
View 3 RepliesI have 2 listview with the same number of lines, what I want to do is when a user scroll the fist listview I want to second one to scroll too.
View 3 Replies