Get Number Of Columns In A DataRow Type?
Jul 7, 2009How can i get the number of columns in A DataRow type?
View 9 RepliesHow can i get the number of columns in A DataRow type?
View 9 Repliesi have to do the same work in vb as i have done in c#:
[URL]
I need to display a column called Full Name in the my datagridview, but the datasource (datatable) does not have a FullName column. It only has FirstName and LastName columns. I'm setting up my DataGridView like this:
[Code]...
im wondering which way may be better to find out the number of cols for a row:
1) row.Table.Columns then count
2) row.ItemArray then count
3) am i missing something, is there a much more "direct" way to do it?
basically i'm trying to reproduce the following mssql query as LINQ
SELECT DISTINCT [TABLENAME], [COLUMNNAME] FROM [DATATABLE]
the closest i've got is
Dim query = (From row As DataRow In ds.Tables("DATATABLE").Rows _
Select row("COLUMNNAME") ,row("TABLENAME").Distinct
when i do the above i get the error
Range variable name can be inferred only from a simple or qualified name with no arguments.
i was sort of expecting it to return a collection that i could then iterate through and perform actions for each entry. maybe a datarow collection?
As a complete LINQ newb, i'm not sure what i'm missing.
i've tried variations on
Select new with { row("COLUMNNAME") ,row("TABLENAME")}
and get:
Anonymous type member name can be inferred only from a simple or qualified name with no arguments.
to get around this i've tried
Dim query = From r In ds.Tables("DATATABLE").AsEnumerable _
Select New String(1) {r("TABLENAME"), r("COLUMNNAME")} Distinct
however it doesn't seem to be doing the distinct thing properly.
Imagine the following scene: I have one table which have tree columns (ID, Number, Name).
A Select query result on this:
code:
Now, the user deletes the Number 3 and 4. So, now the Select query is going to be:
code:
And I want to have:
code:
How can I organize the column?
i am getting the xml using readxml method. And then display the data in datagrid. But number type columns comes as string type in the dataset. So when datagrid displays , sortingdatagrid columns is not correct. For example it sorts like this:
Salary
1180
12133
[code]......
I want to get a value from an item in a DataRow and I would like to store the result in a Nullable Date field.
I see (in VB) that there appears shared "Field" function on the object System.Data.DataRowExtensions. Here's from the Object Browser:
Public Shared Function Field(Of T)(ByVal row As System.Data.DataRow, ByVal column As System.Data.DataColumn, ByVal version As System.Data.DataRowVersion) As T
Member of System.Data.DataRowExtensions
[Code].....
Does somebody have a better way to move values to and from a datarow into Nullable types?
..OR is there a built-in handy function to do this so I don't have to define my own?
i want to set a default number and you type in a textbox a random number it should tell you whether it's high or low ,and when you typed in the right nmber it a lable should says something like you win .And also how can you change PART of a lable by typing in a text in a DIFFERENT FORM
View 6 Repliesi have a column in datagridview composed of numeric as well as aphanumeric. What i want is when the user sorts the column, it will be sorted according to its number value, 1,2,3,4,5,6,7,8,9,10. However it my current module, the program sorts basing the first digit of the column. like 1,10,11,12,2,3,30,31.
i was thinking of converting the type to number so that it will be arrange properly, is this possible in the datagridview to covert type? because i saw only a readonly property celltype? i have also tried casting it in the sql query itself to INT but it did not work.
Using the ListBox1 properties I tried to set the number of columns to 2 but could not do it.
View 2 RepliesIf I am to update table 'Province' in databse get "Value of type 'Boolean' cannot be converted to 'System.Data.DataRow" Is there any other easy method to update table in Access Database?
Imports System.Data.OleDb
Public Class Form4
Inherits System.Windows.Forms.Form
Dim myadapter As New OleDbDataAdapter
[code]....
How do I specify that I want two columns on a checkboxlist?Below is my code:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Not Page.IsPostBack Then
Dim di As New IO.DirectoryInfo("\bk00app0001Images")
Dim imageArray As IO.FileInfo() = di.GetFiles()
[code]....
How do i get the number of columns in a sqlDataReader after executing sql statement ?
View 4 RepliesI've got a question about Listboxes in Visual Basic 2008 Express. I have a fair bit of experience with Office (both 2003 and 2007) and use the listbox in office all the time. The thing I like most about it is the ability to set the number of columns so I can have a string for the user to see and a second column of 0 width that holds my ref number.
So when I needed to do the same thing in VB 2008 Express I grabed the Listbox control and.....hit a brick wall. As far as I can find out from the help files and searching the web the Listbox control only shows one column really. Ok so it might wrap to a second column to save the user having to scroll but its still basically one column. There seems to be no way of having something like in Office.
I know I have no code, but I don't have any code for this. I'm just asking in case I'm missing a control or something obvious. Hell at this point I'm almost tempted to create my own Listbox control that acts the way I need but thought I'd ask before heading down that route.
Using Microsoft Visual Studio 2010 Ultimate - VB.Net
I'm writing an application where as many of other applications fulfill the requirements to be as an app , having it's statistics schema. Thus I made a form where I have a combox(of query category), a textbox(as searchfield), two datetimepickers(from and to) a listview and a button to fire the event with functions in it. I'm all set except for a minor issue I've encountered during my very first experiments with ListView control. Thus far I didn't know that VB users are stuck with that control's property options (whereas DataGridView has way too many), especially when it came to Column reordering/s. With the simple but not satisfying property Sort I couldn't find a proper solution to my issue.
when I click on of the columns in the listview to do a Number/Date/Text reordering (descending>ascending, via-verse). Not to forget to mention there a limited number of columns most likely 2-4 max.
The listview control has lvResults name and has for now columns inserted as "Country" and the other for subitems "Total Spent".
One e.g. of the values inserted to it is like this :
[Code].....
If pressed on Total Spent, should reorder from highest to the lowest number and via-versa. If pressed on Country should reorder from A to Z or via-versa.
I am using this method to create a csv file using vb.net.
protected void btnExportCSV_Click(object sender, EventArgs e)
{
Response.Clear();
[Code]...
This code is creating csv file. But i dont want any extra column in csv.
I'm working with Microsoft Word and trying to generate a table with headings that may span one to three columns. I'm having trouble figuring out how to do this. The table should look something like the following:Counters
Times (hrs)
Flows (gals)
Day
Regens
Well Starts
[Code]...
To get it to look this way, I'm not exactly sure what to do from VB.
I need to have multiple lines in a cell, so I use DataGridViewTextBoxColumn.DefaultCellStyle.WrapMode =DataGridViewTriState.True. I add columns (datagridviewtextboxcolumn) in designer. Then bound datagridview to a table which has exact the same columns as datagridview. Then I find that datagridview has duplicate columns: the first column is empty (which I guess is added through designer), the second column is filled with data from table. My question is how to correctly allow multi-lines and bound to a table at the same time?
In Designer
Friend WithEvents DGV As New System.Windows.Forms.DataGridView
Friend WithEvents columnClient As System.Windows.Forms.DataGridViewTextBoxColumn
Friend WithEvents columnAccount As System.Windows.Forms.DataGridViewTextBoxColumn
Me.DGV.Columns.AddRange(New System.Windows.Forms.DataGridViewColumn()
[Code].....
I have a datagirdview which I need to process.. I have more than 50000 rows and 200 columns in it. DataGridView accepts columnindex and rowindex only in the form of integer. Is there any way in which I can use long instead of integer.
View 2 RepliesDecimal type columns have Precision and Scale where the length of the integral part of the decimal would be Precision - Scale, if the Precision is 4 and the Scale is 2 then the integral part can only contain 2 digits (4-2). As such I will probably need a control that I could set how much it should accept on its integral part. In that regard I am not sure which control is best for such cases, I could try to make a usercontrol that will handle that but is there any other control out there that I could utilize for this purpose, intrinsic to .Net or a custom control out there? I could also just validate the data keyed-in but the above solution seem to be more user-friendly. Curiously, when databinding such Decimal type columns, how is it handled when the specified integral part exceeds the allowable size (Precision minus Scale)?
View 1 RepliesI've got a number of columns the user can sort by (Name, County, Active) and that's easy but messy. Looks something like this...
Select Case e.SortExpression
Case "Name"
If (isDescending) Then
[CODE]...
What I would LIKE to do, is something more ... like this
Private Function SortThatList(ByVal listOfStuff As List(Of Stuff), ByVal isDescending As Boolean, ByVal expression As Func(Of Stuff)) As List(Of Stuff)
If (isDescending) Then
[CODE]...
But it doesn't like the datatype (Of TKey) ... I've tired Func(Of stuff, boolean) (got something in c# that works nicely like that) but can't seem to get this one to do what I want.What's the magic syntax?
i would like to ask if how do i create a column of picturebox.. something like a thumbnail, with a specified number of columns inside a form.. the number of picturebox depends on a variable.. has anyone done this?something likeimage1 image2 image3image4 image5 image6
View 2 Replies1] Is there a way to declare an array of mixed type [e.g.] column 1 as string, columns 2 through 5 as integer.
2] Is �Dim myArray( ,5 ) as type� a valid statement and if so will it result in a 5 column array of unspecified length?
I am trying to program a noise reduction algorithm that works with a set of datapoints in a VB.NET DataTable after being helped with my other question. Basically, I want to take two integers, a coordinate value (yCoord for example) and a threshold smoothing value (NoiseThresh), and take the average of the values in the range of (yCoord - NoiseThresh, yCoord + NoiseThresh) and store that number into an array. I'd repeat that process for each column (in this example) and end up with a one-dimensional array of average values. My questions are:
1) Did anything I just say make any sense ;), and
2) Can anyone help me with the code? I've got very little experience working with databases.
[Code]...
I have two datatables with similar structures that I want to make one existing row to be updated from another datatable.
For example, "tableA" has three columns: "one", "two", and "three"; with "one" being the primary key...
and "tableB" has three columns as well: "one", "two", and "three"; with "one" being the primary key.
Say there is a row on tableA that is different than a row on tableB (with a matching primary key). What I wanted to do, as efficiently as possible, is to take the that row from tableB and replace the one on tableA so it'll be modified.
I'm not sure if there's an easier way of doing that instead of using loops for setting the row's items.
Code.
Public Function comb1(ByVal SName As String) As DataTable
Dim dt As New DataTable
cmd = New SqlCommand("Select Distinct RName from tb_RS_New", con)
[Code]....
While loading the page, the error was thrown as "input array is longer than the number of columns in this table"
So I created this ListView user control in VB, and specified my data source. The layout I used is "single row" layout and the paging is enabled. However, the result is exactly 10 columns (10 windows) for the row. I'm wondering how could I make the default column to be 5? I checked the properties and there seems to be no such property that controls how many columns to start with for the row.
Edit: code for reference
<asp:ListView ID="ListView1" runat="server" DataSourceID="RssDataSource1">
<ItemTemplate>
[code].....
im trying to create a program where the user will type in a number then choose the units its in and units it will be converted to from 2 comboboxes. The output should be changing as different units are clicked without a button.
Public Class Convert
Sub Calculate()
Dim Unit1 As Double = (ComboBox1.SelectedItem)
[Code].....
i try to update the table but not sucessful. In access database the following fields with datatype as under;
Parameters=text
Value=Number
Units=text
[code].....