IDE :: How To Clear DataRow
Oct 5, 2010Code is in VB 2008,
In code i am using Datatable, using that select method datarow
Dim dt as New Datatable
Dim dr() as Datarow = nothing
[code].....
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Create A CLEAR BUTTON Loop To Clear All Textboxes?
Dec 13, 2011this is currently my code to clear my 5 textboxes
Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
TextBox1.Clear()
TextBox2.Clear()
TextBox3.Clear()
TextBox4.Clear()
TextBox5.Clear()
End Sub
Updating A Datarow With Another Datarow?
Apr 28, 2010I 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.
Clear Dataset But Get Error Sometimes If It Is Empty When Try To Clear It?
May 17, 2009I have a timer that runs every time by itself, and for the code the runs in it I would like to have it clear the dataset before it does anything, the timer runs every 10 seconds, so I tried to do dataset.clear but it would crash if the dataset had no values
View 4 RepliesClear Hyperterminal - When Press "ctrl+L" Is To Clear Terminal Screen How To Write The Code?
Jun 23, 2011in hyper teriminal when i press "ctrl+L" is to clear terminal screen how to write the code in vb.net? Hyperterminal is connecting to serial comport.when i try this it work and return line on debug
serialport.writeline ("at+cmgl=1")
i try this but not work and it still show some lines on debug
serialport.writeline (vbcrtl +"L")
serialport.WriteLine("vbCrLf + l")
.net - Clear() Or Txtbox.Text = "" Textbox Clear Methods
Sep 20, 2010way to clear textboxes in VB.Net and what is the difference between the two methods? I have also seen people be critical of folk using clear objects on their forms and i can see why but in this case, i am only learning.
txtbox1.Clear()
or
txtbox1.Text = ""
Clear All The Data In Data Grid View Without Clear The Binding Source?
Jul 15, 2009wan to ask about anyone know the code about how to clear all the data inside the data grid view without clear the binding source...
View 1 RepliesWhy Did Clear() Clear Both DataTables
Feb 28, 2011In my winform program (in vb.net) I wrote:
Dim dt As New DataTable
'Get data from DB into dt
'...
[Code].....
But when I run the program, Clear() cleared both dt and dttemp! Why? Aren't dt and dttemp supposed to be two distinct instances of DataTable?
(I finally found a solution - dttemp = dt.Copy() instead of dttemp = dt. But I still can't see why Copy() was necessary in this case.
StreamWriter Clear (clear The File "make The File Blank Again") And Move
Mar 26, 2010I am using the StreamWriter to create a log file for my application. However I do not see a method on how to clear the file (make the file blank again). Also before I clear the file I want to rename it so that I can have multiple log files, a new one produced everytime the application runs.
[Code]...
Get Next Datarow?
Jun 29, 2010I am trying to look at the next datarow in a datatable such as For Each dr in dt.rows
type = dr("Type")
type2 = dr("Type")
how can this be the next record? Of course, I would need to write an exception for the last record...
Set The Value Of The Dtp From A Datarow?
Mar 16, 2011I have a form with a datetimepicker. On load of the form, I set the value of the dtp from a datarow, with the following vb.net dtpRequiredDate.Value = dr.Item("RequiredDate")
This works fine. But when the form is loaded subsequent times in the session (form is not disposed on closing, shown as dialog), when presented to the user it just shows todays date, not that set by the above code. Stepping through code, the Onload code runs, and the dtp is set by the above code. Checking the value in debug at this point, the value of the dtp is correct. There is no further code in onload. But by the time it is displayed to the user shows todays date again. I have set a break point on the valuechanged of the dtp but it never fires again after it has been set by the above code.
.net - DataRow Is Not Changed
Oct 4, 2011Can anyone explain exactly why Method 1 in the following code does not alter the DataTable where the other 2 methods do? It's obviously some kind of referencing issue, but why exactly?
[Code]...
Adding A New Datarow?
Mar 14, 2011I am trying to add new operators (their name, category, password etc) to a dataset called "operators". (Though I could be adding any new datarow to it's relevent dataset). My program has allowed for the entry of all relevent data and filtered it to make sure it is acceptable. The user has pressed the UPDATE button and my program must now add the new datarow. (My code is in bold!).
I assume that I must first establish a connection to my database, so I start with :-
Dim Conn As New OleDbConnection(ConnectionString)
'I feel that something is needed here to reference OleDbDataAdapter - but what?
Conn.Open() 'Is this line needed?
Dim DSetOPERATORS As New DataSet("operators")
Dim DRowOPERATORS As DataRow = DSetOperators.Tables("operators").NewRow
[Code]....
Get Data Out Of A DataRow?
Sep 8, 2009I am trying to get data out of a DataRow. Example:
Dim dr_simslot = dsFSC.tblSimSlot.Select("SimID=" & simID)
What I want is to say something like this:
Dim temp = dr_simslot.columnname
This is because I know only one record will be in the datarow.
Get Last Row In (for Each Row As Datarow In Dt.rows)
Mar 31, 2012for each row as datarow in dt.rows
if row is last row in dt
msgbox("last row in datatable")
end if
next
how do i detect the last or first the row is in datatable
Get PrimaryKey Of DataRow?
Apr 19, 2012I have a master DataTable that may contain some DataRow.RowError. I create multiple subset DataTables from my master DataTable using the DataView.ToTable method whenever the user wants to apply a filter or sort to the master table. However, the ToTable method does not transfer the RowError property of the data rows in the master table to my new subset table. So in order for me to transfer the row errors from my master table to my subset table I have to use a loop. The code below works fine, but with one exception (see below code).
Dim dtMaster As DataTable = Me.ds.Tables("Current")
Dim dtSubset As DataTable
Dim dv As DataView
[Code]....
Note, the primary key may contain 2 columns, however this is a rear case. If you know of any other solutions to transfer row errors let me know. I don't have to use the Find method.
Increment Datarow By Value 10?
Aug 9, 2009Public Class frmVisitor
Private dbConnection As New OleDb.OleDbConnection()
'To add a DataAdapter
[Code]....
.net - Why Does The Compiler Think This Is An Object Instead Of A DataRow
Aug 2, 2010I'm using a LINQ query to translate data inside a DataTable object to be a simple IEnumerable of a custom POCO object.
My LINQ query is:
Dim dtMessages As DataTable
'...dtMessages is instantiated ByRef in a helper data access routine... '
Dim qry = From dr As DataRow In dtMessages.Rows
[code]....
However, the compiler is throwing a warning message under dr As DataRow with the message: Option Strict On disallows implicit conversions from 'Object' to 'System.Data.DataRow'.Why am I getting this error and what do I need to do to fix it? I would have thought that dtMessages.Rows returned a collection of type DataRow. Is this not correct?
.net Loop Through Datarow And Add Each Value Into A Listbox?
Jul 23, 2010Private Function ColumnEqual(ByVal A As Object, ByVal B As Object) As Boolean
[Code]...
Addin Datarow In Datatable?
Mar 15, 2012I've VB.NET function that reads data from an Excel sheet and adds rows in a Datatable.
Private Function LoadDataToRows(ByVal TableName As DataTable, ByVal Header As System.Collections.Specialized.StringCollection) As Boolean
Dim HeaderDataExcel As String = String.Empty 'Data Header
[Code].....
But no data was add to the table, only emty rows.
Adding Datarow In Datatable?
Mar 15, 2012I've VB.NET function that reads data from an Excel sheet and adds rows in a Datatable.
Private Function LoadDataToRows(ByVal TableName As DataTable, ByVal Header As System.Collections.Specialized.StringCollection) As Boolean
Dim HeaderDataExcel As String = String.Empty 'Data Header
[Code].....
Binding Datarow To Textbox.?
Dec 16, 2010I have the following code where I'm trying to bind a datarow to a textbox.
Me.TierNameText.DataBindings.Add("Text", Me.m_TierRecord, "tier_name") Problem is, when the form is displayed no text is shown in the textbox.
This code runs before I call the form's ShowDialog method. I stepped through the code to make sure the datarow has data, and indeed it does.
I rarely use databinding but thought I'd try it this time.
C# - Converting A DataGridViewRow To A DataRow?
Sep 17, 2009setting a DataRowView equal to my DataGridViewRow.DataBoundItem, then using the DataRowView.Row property (In my code below).
Here's my code:
Dim tblTemp As New DataTable()
Dim row As Windows.Forms.DataGridViewRow
Dim rowView As DataRowView
[code]....
C# - Filter Datarow In Dataset?
Aug 1, 2011I have dataset like
<DATASET>
<SALES_DO_INDEPENDENT>
<SALES_DO_INDEPENDENT_ID>22</SALES_DO_INDEPENDENT_ID>
[Code]......
Converting A DataGridViewRow To A DataRow?
Mar 22, 2010I have a DataGridView that is bound to a DataTable thru the code. I want to be able to modify the data when a row is selected from the Grid. How do I reference that row of data from the grid so I can convert it into the DataTable row to be updated? I'm trying to do something like this:
Dim row as DataGridViewRow = DirectCast(dgvAddress.CurrentRow, DataRow)
This isn't working. I'm getting an error basically stating that I can't convert a DataGridViewRow into a System.Data.DataRow.
[code].....
Converting A String To DataRow?
Jun 21, 2010I have a combobox that pulls a list of values from a database. When a new entry is entered I want an entry in the combobox to read "New record". However, from what I have seen I can only insert and object, such as a DataRow, into the combobox. Is there anyway I can convert a string to to a DataRow, or some other object and insert it in to the combobox? I know there is I am just rusty on my vb.
View 3 RepliesDataRow.AcceptChanges Not Working?
Feb 17, 2011I am having an issue with a DataRow not being updated in my DataTable. The trouble is my value is not being changed in the row.I have done a simple example which shows what I am trying to achieve. My row does not change values...ever...and no errors are found
Dim cm As New DataTable
cm.Columns.Add("Name")
cm.Rows.Add("Craig")
[code].....
How To Keep Original Values In DataRow
Aug 16, 2010I am using VB 2008 and Access DataBase. My code need to store original data values for row being updated to compare it with new values later. For this to accomplish I wrote following
Dim dRowOriginalRow
As DSetPurchaseSale.PurchasesRow
Private
Sub btnEdit_Click(ByVal
sender As System.Object,
[Code] .....
When I am running this code, i am not getting the original values in dRowOriginalRow variable insted it is also updating with new changes made in controls, so the dRowOriginalRow and dRowModifiedRow are always same. Again may I use Equal To sigh to compare both rows as I did in my code?
True : dtPurchaseDate.Focus()
How To Sort List Of Datarow
Aug 5, 2011i have a list of datarows. each row is having mutiple columns like userid,date,flag,etc.i want to sort the based on date. how can i do that ?
my code is:
Dim
listOfRows As
New List(Of
DataRow)()
[code]....
i want to sort the listOfRows in ascending order of date which is a column in a row?
Implicit Conversion Of DataRow?
Feb 19, 2009I do the following:
Dim rw() as exportDataset.vendorPricingRow = ExportDataset.vendorPricing.Select("field1 = 1")