i want to prevent user from adding same data on my database... (using access as database)
let say i have 5 fields on my database... ID, Name, address, contact, email... binded to textboxes... idTextbox, nameTextbox, addressTextbox, contactTextbox, emailTextbox.
if the user add a data.... and clicks the save button (saveButton) a messagebox will show a message saying that the data he/she entered already exist..
the messagebox will only show if the user entered a data with the same Name.
i'm working on a voting system but im having problems in adding records... i have two a primary key, the idnumber and the address. the address is where I base if that certain address already voted. but the problem is everytime i try to add a record with the same address (ex. Block 1 lot 4), the data is duplicated which is not output i want. the program should detect that there is already an existing address.
I have this code and it is not working correctly. Note: The code must check the if the data is valid every time the user enters a new datai have 2 columns in my table
Code: Private Sub Table_CellValidated(ByVal sender As Object, ByVal e As Telerik.WinControls.UI.CellValidatedEventArgs) Handles Table.CellValidated
I'm writing a program on CD Collection. My problem is write a code that prevents a user to enter a CD collection name that is already stored in the filename.txt.
The rest of my program is okay, but the only problem is something do with btnAdd control.
Here's my whole program:
Option Explicit On Option Strict On Option Infer Off
I've got this problem. I have no clue how to prevent a duplicate from being entered in a combo box in VB2008. The information that is to be compared to is in a text file. What I have now works, but I have left out the prevent duplicate part.
Am developing a resume data retrieving software where data is stored in one parent table and 4 child tables as such:
Resume_table ----> Parent table holds ----> Res_ID, Emp_ID, Lang_ID, Task_ID & some other static data
Employee_Table--->which is referenced directly to Resume_Table.Emp_ID similarly ol other 3 tables are referenced to the main parent table Storing and retrieving data is all working fine as long as I am retrieving 1 record for each child tables But some times there might be couple of languages and only single records for other child tables.In dat case as the four child tables are ol in separate subreports whch are called onto the main report whch prints as cv gives redundancy in data i.e by giving duplication of ol records twice which were single records during entry, which i think follows the language table if it consist of 2 records.am using a join query to call these records onto crystal report...
I have this problem, I can create a setup for my app/database but everyone can open the backend file which is an MS Access database. I want it so we can only access the database using the frontend app.
In a VB App. I read an Access table and display it to the UserForm... I would like to prevent and skip Access database update "for the sake of application efficiency and speed" if user has not changed the data displayed on the userform... How can I do that?
This program is going to submit GET data to our webpage. However, we don't want users accessing the webpage any other way than the program. We can prevent users from sharing the program using HWID authentication, but nothing prevents them from using a packet scanner to get the URL of the webpage. We thought about user-agent authentication, which we will implement, but user-agents can easily be spoofed.
how can we prevent users from accessing the webpage directly, instead of through the program?
Currently we will be implementing:
HWID Authentication to use the program User-Agent Authentication to access the web page Instant IP Blacklisting to anyone accessing the webpage without the proper User-Agent
I am using Synclock to prevent multiple threads from logging text messages to the same file at the same time, but this doesn't seem to work:I get frequent sharing errors on the logfile, within the synclock block.The Synclock is using the variable holding the filename, because it exists all the time and because it is always the same object, whatever class instance or thread I'm in.[code]Despite using Synclock and a Using block around the code, I keep getting this error in the sw.WriteLine(Msg) line:System.IO.IOException: The process cannot access the file '(filename)' because it is being used by another process.Should I use some other type of object than a string to synchronize on?I cannot use a user interface object (button or so) because it is a windows service project.It was written and compiled in Visual Studio 2008, but targeting the 2.0 framework because it has to be able to run on some old Win2000 machines.
I coded this program. It has three forms, when I try to open the [Design] on one of the forms it give me this error: To prevent possible data loss before loading the designer, the following errors must be resolved:
I have the following code for SQL insertion, but how can I prevent data dublication in vb.net so that the same data is not entered twice? I mean can I add a exception in my code to check if one of the field in the sql server table contains the same data? [code]
I am updating my last post so hopefully someone will help. I have following code that will move a cell to the next column when hitting the enter key while doing an edit. It will even check the row at the last cell to validate data is present.
However, if there is no data in a cell and I press enter, the focus moves to the next line like it normally does. I need to prevent the user from moving or clicking on any cell until the cell they are on has data in it. Here is the coe I have used[code]...
My program becomes unresponsive when I download Data using WebClient.OpenRead(). What can I do to prevent the program from freezing while downloading the Data?
I have a project that uses a number of DataGridView controls. Most of the cells are of the DataGridViewTextBoxCell persuasion. I declare my controls like so:Dim MyCell as DataGridViewCell Later I specify whether they are DataGridViewTextBoxControls or DataGridViewComboBoxCells like so:
MyCell = New DataGridViewTextBoxCell MyCell = New DataGridViewComboBoxCell None of the places in my code require the ability for the users to enter their own values in the Combo Boxes. That is, they are either hard-coded or the values are gathered from other data within the application.
Currently, users can highlight a combo box control defined as shown above and begin typing anything they like. For example, I have one combo box that offers the user a selection of integers between 1 and 9. I can highlight the combo box cell and enter "Hello, World!" if I'd like.What does it take to disable this ability? I'm sure there's a property, but I have yet to find it. I have searched the Internet, and have found only the ability to have user-entered values added to the list and a stream of data-binding tutorials.
Here's an interesting problem, and I'm looking for a pattern that will keep it all workable. I am building a smart-client app for a school system. It will contain information about students including their report cards, sick days, and so forth. it will generate student-level reports, including their report cards, each rich with very personal commentary by their teachers. The app will retrieve data from the remote server via web services.
Is there a way to prevent a user from entering data into a ComboBox, rather then selecting, or can anyone suggest a routine to catch and prevent entries so the user can be made aware the they are not acceptable?
Background: I have an web form that autpostbacks a list of bundles to a listbox based on the carriers selected. When Postback happens, all user entered data is cleared. How do I prevent the AutoPostback function from clearing entered data from the forms? [code]
I'm using interop.msxml2.dll to open XML and txt files off an Internet server. The response that is received from the server is stored in my application's variables. I've recently noticed that the application doesn't always update the information when it goes to download a file that it has already downloaded in the past. For example, if it downloaded a file off the server when it started up, then when it attempted to download the new, changed file 5 minutes later, it would still return the same value as the first one. Even after closing the application, it would still return the incorrect, older value. How to stop this "caching" of data, and only allow the program to download the latest file off the server.
I am using Oracle 11g client, with ODP.NET. I am trying to add conditional Transaction handling.
Dim ds As New DataSet() Dim txn As OracleTransaction Dim _beginTransaction as Bolean = true Using conn As New OracleConnection(ConnString)
[Code]...
How do I fix txn being nothing / null? The error is: Variable 'txn' is used before it has been assigned a value. A null reference exception could result at runtime. Edit: to RichardOD for pointing out that you can not explicitly declare that a transaction cannot be opend up on stored procedures via ODP.NET. I have verified that this is an issue. BUT We still haven't figured out why the error is occuring. I understand that txn is initially given a value w/in an if statement, but being defined outside of the try/catch block should make that irrelevant.... right? Or is that bad coding?
I am currently having a headache on how to solve this problem that i am facing.here is the situation:I have a combobox and a list box on the main form. The combobox will get the data from the ms access database.In the database, i have the details of a person's IC, Name and DOB say for eg on one entry I have D215311523C,SHAWN,13/04/1987
So now, my combobox on form load will show the list of dates in the database to allow the user to search base on the date itself by clicking on the selected date. So when the user clicks on the particular date say 13/04/1987, people in the database whose birthday is 13/04/1987 will be shown on the listbox.Meaning to say if i have 3 entries whose dates are the same 13/04/1987, 3 entries will appear. If there is only two entry, then two results will be shown.
I've gone through various thread, posts, classes and walkthroughs on sites but seem to be coming up short either in my understanding or what is/should be going on.I have a very simple data entry tabcontrol (think like microsoft excel but textboxes, labels and the odd combobox rather than a grid). When I click one tab it creates a new tab and names it according the sequence (no problems so far). Here is the crotch kicker (for me at least). I need the first tabpage layout on all additional tabpage so that data can be entered in each separately and stored with constant "processing" (adding and subtracting ).What would be the best approach to doing such a tabpage duplication?
Currently a User control library inheriting from tabpage seems like a good idea but with the 40 or so controls on it is this actually going to function like the first tabpage (as in the one i have now not the one I'd have if i used the user control instead).Do I take the raft of code the designer creates automatically for the tabpage and its controls and simply add them to the click event? Would this create duplication problems with name or would it be ok as they would be tabpage1.lblName and tabpage2.lblName?
i developed a project using VB.Net 2005 and sql server 2005 standard edition at back end. now its complete and have to deliver to company now. but i am afraid that the company may reproduce a new copy of this software from the original and may sell to any other company or in open market. I want to implement some mechanism on my project for its security, which enables it to not to work on other computers or some similar type security.
I have a program connecting with a database.. so when add record in it, i want to validate for the duplication of ID in database..
here's my code for add button: Private Sub cmdAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdAdd.Click dSet.Tables(0).PrimaryKey = New DataColumn() {dSet.Tables(0).Columns("WatchID")} 'The table primary key is the WatchId
