Checking For Duplicate Values In Strings?
Aug 5, 2009am new to VB.NET and i was wondering if anyone here knows how to check for duplicate values in strings?
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Checking For Duplicate Values Before Attempting Insert?
Apr 14, 2011I have a form where two fields on the first page of the form make up the primary key. I want to check for duplicate values before attempting to insert the record, since I don't want the user to go all the way through the form only to find out they can't submit it. So I'm trying to check for duplicate values when the user tries to go to the next page of the form. I wasn't quite sure how to do it, and sure enough I'm getting an error. ("Object reference not set to an instance of an object.") The problem is apparently in my if statement, "If myValue.Length > 0 Then", but I'm not sure what needs to be in place of that.
Protected Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles CustomValidator1.ServerValidate
'get values
[code].....
VS 2010 Read Through A Textfile Line By Line Checking For And Removing Duplicate Values?
May 16, 2012How do i read through a textfile line by line checking for and removing duplicate values?
View 1 RepliesChecking For Duplicate Row In DataSet.RowChanging?
Feb 7, 2012I am using the DataSet to test for data errors on a DataGridView (to give the user feedback before they save changes back to the database). RowChanging event has the code at the bottom and this manages error messages on the DGV via an ErrorProvider. I want to add something to this code that esnures there are no duplicate rows (it's a 2 column table and one of those is the autoincrement PK). However I cannot work out how to do this and since the column in the database is set to Indexed (No Duplicates) it will throw an Ole error if I don't handle it, I could manage it in a Try block around TableAdapter.Adapter.Update but would prefer not to add needless round trips to the DB when it really ought to be simple to do it in the code (and preferably in the DataSet, not the form).
I found the following code (Forum Post) and try as I might I can't make it work since I can't get access to a DataTable within the RowChanging event that allows me to run DataTable.Rows.Find().
Dim expression as String
Dim matchingRow as DataRow
matchingRow = Mytable.Rows.Find(expression)
In my case:Mytable would be some kind of reference to the table / dataset etc.
'expression' would be e.Row.compclass.ToString
* a reference to the database table the form works with (bearing in mind that this code is in the DataSet not in the form). I've tried properties/methods of the DataSet itself; creating a new DataTable and linking it to the DataSet Table (or DB Table); creating
a new DataTable and loading it with the table contents - Searching MSDN and the forums hasn't popped anything up yet.I'm currently experimenting around this code:
Dim strCompClass As String = e.Row.compclass.ToString
strCompClass.Trim()
Dim foundRow As DataRow = ???.Rows.Find(strCompClass)
[code]....
This is the current code in the RowChanging event. The new code would be inserted after the last End If in the code below.
Private Sub ref_compclassDataTable_ref_compclassRowChanging(ByVal sender As System.Object, ByVal e As ref_compclassRowChangeEvent) Handles Me.ref_compclassRowChanging
If e.Row.HasErrors Then
[code]....
Checking One Listbox For Duplicate Entries?
Sep 10, 2009I've read through all the search results for this and haven't quite got it yet. I often get given Excel spreadsheets of file names and have to check through them for duplicate names.I am making an app to do this for me. I've extracted the data from Excel I'm just having issues with checking for the duplicate. I've tried 2 different ways I found online and neither are working for me,
[Code]...
VS 2010 Checking Duplicate Data
Apr 1, 2012I have this line of codes here to check if the records exist.
Try
If StudentInfoBindingSource.Find("StudentNumber", StudentNumberTextBox.Text) = -1 Then
ToolStripLabel4.Visible = True
[Code].....
This codes works perfectly but there is a problem, if I close that certain form and reopen it and try to input the same student number, the ex.Message for the Try appears and still the progressbar() command executes although the data will not be saved. I want to ged rid of the execution of progressbar() how can I make it work? And as much as possible I want the message box in Else to be executed and not the msgbox in try catch.
Checking For A Duplicate On Table Before Inserting The Field?
Dec 22, 2009I need to check if a Commodity entered into (TextBox1.Text) already exists on my table before i insert it. I'm having issues checking if the number of rows returned from my Select is equal 0? Also i'm wondering should i be checking for an exception and open/closing my connections each time i make a call to my DB or is the way i have it coded below OK?
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
Try
myConnection = New SqlConnection("server=localSQLEXPRESS;uid=sa;password=12345;database=My DB")
myConnection.Open()
[code]....
Checking For Duplicate Date In A ListBox Control?
Apr 13, 2011I am being forced to us Option Strict in my class and this is a new feature to me. Right now my code is having trouble comparing the current time to be added (A Date) with the list of times (Object). Here is my complete code
Option Strict On
Public Class schedulebookForm
' handles Add button user event
Private Sub addButton_Click(ByVal sender As System.Object, _
[Code]....
Problem is inside TimeTaken Function, inside the For.. Until. Basically the If... Then Statement. I tried. .contains, Select Case, and a few other alternatives.
Checking For Duplicate In Listbox Item Turns Out Weird Error
Apr 21, 2011I'm trying to add a string to a listbox if there is none exact string existed inside, but it turns out a very weird error. Look at this.
On form_load, I have this:
AddHandler Server1.OnUserLoggedIn, AddressOf HandleUser
And then,
Public Sub HandleUser(ByVal username As String)
'Here, you handle adding the text to a text box.
Me.Invoke(New PrintMessageDelegate(AddressOf AddUser), username)
End Sub
[Code] .....
The output is when I connect the first client, it works fine. But, when I try to connect the second client, it prints out three times both the listbox1 item and the txtDisplay. It's like get caught in loop, but I have tried other kind of loops like for each and other string comparison too, still work that way.
VS 2010 Checking Listbox Items For Duplicate Before Adding New Item?
Sep 8, 2011How would one go about checking a listbox's items for duplicates? Basically I need to write a program that displays the teams from a text file provided by my instructor, in alphabetical order. I can do that, but what I can't figure out is how to prevent the For loop from adding a duplicate team. What I'm envisioning is:
If teams(i).name is not in lstTeams.Items Then
lstTeams.Items.Add(teams(i).name)
End If
I have a program that compiles and works so far, except for the above problem and my alphabetical order (which I can probably figure out on my own:
Public Class danbrockteams
Structure team
Dim name As String
[Code]....
This works except that my listbox is filled with the team every player is in rather than just listing all possible teams. Not exactly looking for someone to just give me the answer, as I understand things best when figuring them out on my own, so I suppose a hint is what I'm really after.
Find Duplicate Strings In Text File?
Jun 30, 2010I have a text file DIC.TXT.[code]...
View 4 RepliesDuplicate Values In A Datagrid?
Feb 26, 2012I'm using an unbound data grid in Visual Basic. I made the following loop for the purpose of searching each cell and each column for a duplicate value. But for some reason I get a "InvalidCastException" when I try to add a second row.
Private Sub AddJudgeBtn_Click(sender As System.Object, e As System.EventArgs) Handles AddJudgeBtn.Click
Dim exists As Boolean
' ToDo: If the value entered is already on the list, don't add again.
If JudgeList.Rows.Count() > 0 Then
[code]...
EDIT: Adding the entire click event.
Get Duplicate Values From Dgv Into A Combo?
Dec 14, 2011I am trying to get duplicate values from dgv into a combo:
[Code]...
.net - Linq OrderBy On Duplicate Values?
Oct 20, 2011m_ListOfsAllFields.OrderBy(Function(x) x.DisplayOrder)
here I have DisplayOrder = 0 for 2 fields, so orderby is messing up and not ordering properly. How can I use orderby to order this collection?
Avoid The Duplicate Values In The DataBase?
Jan 29, 2011How can i avoid the duplicate values in the Access Database?? I am working in VB.NET, to create DataEntry Form. I have Combobox. When enter the value on Combobox and press OK button then the value should check on the database , if the value is not there then it should save on the db. else the Missage will give "It is Saved".
View 6 RepliesAvoiding Duplicate Values In Database?
Jun 21, 2010I want to insert number for City_Id and City_name , i wrote a query for auto generate number for City_Id,working fine but in the city name i want to avoid inserting duplicate value like if Mumbai is a City ihave already saved then system should not allow that name again. neither in small or in capital or mixed letter.
View 4 RepliesDataGrid Validation For Duplicate Values
Dec 15, 2011I need to validate a particular coloumn in datagrid for duplicate values before inserting into database. I am using datatable.
View 9 RepliesRandom Numbers With Duplicate Values
Mar 9, 2010Get Random value with no duplicate
[Code]...
[2005] Drop Down Duplicate Values?
Jan 20, 2009I have a fairly large Drop down menu:
<asp:DropDownList ID="DropDownList8" runat="server" AutoPostBack="True" OnSelectedIndexChanged="DropDownList8_SelectedIndexChanged">
<asp:ListItem Value="" Selected="True"></asp:ListItem>
[code]......
Avoid Duplicate Values In Datagride View?
Nov 7, 2010How can I avoid Duplicate values in Datagrideview. When I am putting Product Id in Invoice which is adding in datagrideview if it is exist in datagrideview it will Highlight with deferent color and give me massage that this Id is existent in datagrideview
View 4 RepliesDelete Excel Columns And Duplicate Values
Jul 5, 2011I am trying to create a .Net application to edit a excel file by deleting some columns and keeping the columns which we need and then removing the duplicate values based on the first column which is going to be the Serial no. which should have a check to have 6 digits by default like 2563 should be displayed as 002563.
Code:
Public Function GetAllFileContents(ByVal path As String, ByRef errorMessage As String) As IList(Of String)
Dim contents = New List(Of String)
Try
Dim files = Directory.GetFiles(path, "*.xls")
If (files.Length = 0) Then errorMessage = "Please select the files"
For Each file In files
[Code] .....
I am trying to create something different by not only letting me do it for excel files but for say txt and csv files along with it. Removing all the values which I dont want and removing the duplicates and then if possible putting a check on the first column of data that the serial number number should have minimum of 6 characters and then The output file should have all the details in Uppercase
Prevent Duplicate Values Entered By User?
Feb 10, 2012How do I prevent users from a inserting a duplicate value using SQL Query
datatype is VarChar(50)
e.g. the name field has already been defined as "Josh", I don't want it to be able to add another "Josh"
Enter The Duplicate Values.In The Database One Of The Column Is Indexed?
Feb 4, 2011I am sending values from Combobox and Textbox to Access Database in VB.NET.I am phasing the problem when i enter the Duplicate values.In the database one of the column is Indexed.(Yes Duplicates not allow)That column i bind to Textbox("txtperson1").I used the TRY and Catche method to solve the Indexed Problem.when i run the application the value which i enter is not a duplicate that value save on the db. Once i enter the Duplicate value , the message box is showing "The Record alread saved".But After i enter the new value the same message is displaying, it is not saving on the db.
[Code]...
VS 2008 Updating Database - Producing Duplicate Values
Jul 29, 2009Here is my
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=BHgardeners11.mdb;")
cn.Open()
Try
str = "UPDATE Products SET ProductCode = ?, ProductManufacturerCode = ?, ProductsTitle = ?,
[Code] .....
If there is only one item in the database, then this code works. If there is more than one record then the error is produced that it is trying to produce duplicate values. This is down to the Primary key in my database which is the only thing that cannot have duplicate values. However, when I remove the primary key it has the predictable problem that it goes crazy and does weird things.
Error - Create Duplicate Values In The Index - Primary Key Or Relationship
Apr 4, 2011I had restart my program for 5 times, and i still can get through it. the due date just around the corner.
"The changes you requested to the table were not successful because they would create duplicate values in the index, primary key, or relationship. Change the data in the field or fields that contain duplicate data, remove the index, or redefine the index to permit duplicate entries and try again."
Checking 2 Textboxes Values?
Jun 4, 2011Iam trying to Check Values Of 2 textboxex .. n then Print A certain Amount.
[Code]...
Checking Two Values Are Equivalent?
Jun 23, 2010I'm trying to make a small program that helps cashiers to practice typing barcode on their machine. Barcode consists 12 numbers, and it can start with 0. Below are the code I worked on so far.
[Code]...
Checking Values Within A Range
Oct 18, 2011I have 14 values, that change constantly. I need to know how to check each value against each other to see if they are within 250 of each other. [code] I want these two values in the listbox to blink red in the list box. but i always want each value to check every value in the list box. i dont even know where to start short of programming each possibilty with a if than statement and that would take forever
View 1 RepliesLINQ - Create SubList And Skip Items With Duplicate Property Values
Apr 4, 2012The problem is: I have a list of objects, with some containing the same PlanId property value. I want to only grab the first occurrence of those and ignore the next object with that PlanId. The root problem is a View in the database, but it's tied in everywhere and I don't know if changing it will break a ton of stuff nearing a deadline.
So, if I have a list of PlanObjects like such.
Plan1.PlanId = 1
Plan2.PlanId = 1
Plan3.PlanId = 2
Plan4.PlanId = 3
Plan5.PlanId = 4
Plan6.PlanId = 4
I want to take a sub-list from that with LINQ (italics mean an item is not included)
Plan1.PlanId = 1
Plan2.PlanId = 1
Plan3.PlanId = 2
Plan4.PlanId = 3
Plan5.PlanId = 4
Plan6.PlanId = 4
For my needs, it doesn't matter which one is taken first. The Id is used to update a datsbase record.
Checking Combobox Values In Datagridview?
Nov 4, 2008I want to check if two combobox values are equal. The comboboxes are in a datagridview.I found you need to use datagridview_EditingControlShowing to add a handler to the comobo boxes for selectedindexchanged. I can do this with this code.
Code:
Private Sub dgridRegisters_EditingControlShowing(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewEditingControlShowingEventArgs) Handles dgridRegisters.EditingControlShowing
Dim combo As ComboBox = CType(e.Control, ComboBox)
[code]....
However, the message box comes up for every combobox in my datagrid when I change the index, not just the cmbPort2. I would like to have something like this...
If cmbPort1.selectedindex == cmbport2.selectedindex then
'do something
endif
..but it doesn't seem possible.