When my application loops through the first code block below, I get valid data for all datarow fields. [code]...
But I get an error when looping through that code block "Collection was modified; enumeration operation might not execute." [code]...
However, in the second code block, I get a valid record for MgrID, but I get a blank value for the other fields.
When I look in the database, all fields in that table have valid values.
I have an asp.net application where I have a datatable ("DataTableA") that returns just one column ("ProductID").
I want to read each row of "ProductID", process some business logic, then copy both those columns (ProductID & ProductIDBusinessLogicValue) to DataTableB. This DataTableB is then displayed on the asp.net page.
What would bhe the best way to read each row of DataTableA ?
I have three sub tables that I want to process. For each I want to combine the rows, as they are only different by contents in the second column(I want to do the same to the fourth column, later):
how to loop through the rows in excel. I have rich text box that will contain serval line of text i then want the break the text into single lines, that i can do by use richtextbox.line and then use the split method. but the problem when i split the lines how can i put the first line in A1 the second into A2 etc there is no set amount of lines that will be in the richtextboxes so i would need to use some type of while loop i think but i can't figure out how to add a row for each new line any help would be great
my code:
Public Sub ExcelAutomationBtn1() 'Create a new workbook in Excel. Dim oExcel As Object Dim oBook As Object
For Each row As DataRow In dgrFarms.Rows Dim sendtroopid As Integer sendtroopid = row("idColumn") 'Do Something Next
I've been trying to get a loop through a row in just one column in VB.NET for a while now, and i've done my homework on it too. When i use that code above I get:
Unable to cast object of type 'System.Windows.Forms.DataGridViewRow' to type 'System.Data.DataRow'.
I saw another guide which told me to do:
For Each row As DataGridView In dgrFarms.Rows sendtroopid = row("idColumn") 'Do Something Next
But that gives me the error:
Overload resolution failed because no accessible 'Item' accepts this number of arguments.
Dim _tableBackLogs As System.Data.DataTable Do While i - 2 > 0 _tableBackLogs = Global.DataAccess.GetDataTable("SELECT SubjectID,SubjectName,Grade FROM SubjectPI WHERE RegNo='" & CInt(HttpContext.Current.Session("userName")) & "' AND Status='Fail' AND Semester='" & i - 2 & "'") i = i - 2
Doing this replaces the previous data in the DataTable. I want to retain the previous data i.e i want the new rows to be added to the DataTable w/o replacing the previous rows.
Im trying to loop through all rows in a datagrid and enter a calculation in the field in the next column (first column is already populated with appliance names). The code below works but only on the first row. Can someone be good enough to point out my error? For Each row As DataGridViewRow In DataGridView1.Rows
If DataGridView1.Rows(s).Cells(0).Value = "" Then DataGridView1.Rows(s).Cells(1).Value = "0" Else DataGridView1.Rows(s).Cells(1).Value = dtDLopt.Compute("SUM(Measurement)", "Appliance = '" & DataGridView1.Rows(s).Cells(0).Value & "'") End If Next row
I have a dataset that I'm trying to loop through to be able to save any changes made to that dataset and update my database doing so. Can anyone offer any code to do that effectively?
I am trying to use the Select on a datatable and am having some trouble. I got it to find a match on rows in a datatable I fill with data in multiple columns. But I cannot seem to loop through the results to do something with it. Here is my code below. The table is already filled with data.
Is there a way of merging (importing or whatver is the correct terminology is) the data from an Array in to a DataTable woithout looping. I already know how to loop through the array to populate the DataTable with new DataRow but I'm looking for something much faster if it exists. I've got a 1 dimensional String array i.e. 'String()' that I need to populate a DataTable with new DataRows.
I have a form with a textbox and a add button. User can write a name down on the textbox and click add button. it will save in a datatable with auto ID. After that, the textbox is cleared and the user can write another name on the text box and click the button. This should add to the existing datatable on memory with existing ID + 1. Show on the gridview. (this is just for display purpose to confirm it works)
I have a datatable like this. Button1.click() event Dim name = txtname.Text Dim dt As New DataTable dt.Columns.Add("ID", GetType(Integer)) [Code] .....
At the moment I have sometime like the code above. in the real program, it is not just name and it is not just one datatable so i just mock up some code. And this code for aspx. <asp:TextBox ID="txtname" runat="server"> </asp:TextBox><asp:Button ID="Button1" runat="server" Text="Button" /> <asp:GridView ID="GridView1" runat="server"> </asp:GridView>
I Have a datatable in .net. I need to flip the location of two of them. For example, a datatable that the select statement had an order by priority clause. The user wants to up the priority of a single row by selecting it and clicking increase priority, how do i move a row up (AKA flip two rows)
Private Sub error_out(ByVal line As Integer, ByVal err_col As Integer, ByVal err_msg As String) Dim ln = t_erori.Rows.Add
[Code]....
I suspect this is because it's trying to add the same row twice. How can i make this work ? Or what else method could I use to do this ?
I need this datatable because my app is writing some results in there, but any other method to store the results that works with parallel.for would be ok.
The problem is I want merge duplicate serial_no into one row which the value of testong adding to new column. I have tried many ways, but I can't find the solution. Here is my code behind :
I have a datatable object, which is populated from a webservice.Apparently, the web service just throws everything (data) back to me. The data which gets in my datatable looks like this:
I have a Datatable in my code in vb.net. I need to delete rows from the datatable. The name of my Datatable is "temptable".in my row deleting event of a Gridview control. I wrote code as follows:
In the Row_Deleting event of Gridview: temptable.Rows.Remove(Gridview1.Datakeys(e.RowIndex).value)
But,it shows an error as follows: "Cannot cast System.Int32 to System.Data.Datarow".
I have a simple application that uses a database to store usernames and passwords.I have a hidden control that, when activated,should clear all usernames and passwords from the datatable.Then, one admin account is added. I have tried the datatable.clear method BUT while it throws no errors, it doesn't clear the datatable.I have also tried the datatable.reset method, with the same problem. I am now trying this method:
Dim row As DataRow For Each row In Authenticate.Logins row.Delete()[code]....
I have a datatable and I want to create a text file using this datatable. I want that each row of the newly created text file is unique. If there is a duplicate row, then it should add * to both rows ( duplicate rows)
I am using following code:
Dim str As String For Each row As DataRow In dataTable.Rows str += row(1) ' This is text data
I have a DataTable which I want to check if values in three of the columns are unique. If not, the last column should be filled with the line number of the first appearance of the value-combination.
[Code]...
I solved this by iterating the DataTable with two nested for loops and comparing the values. While this works fine for a small amount of data, it gets pretty slow when the DataTable contains a lot of rows.My question is: What is the best/fastest solution for this problem, regarding that the amount of data can vary between let's say 100 and 20000 rows? Is there a way to do this using LINQ? (I'm not too familiar with it, but I want to learn!)
i want to make a datagrid with 2 columns and many rows
the columns i want to have databinding with a datatable i want the 1 row 1 column of datagrid have data from 1 row of datatable i want the 1 row 2 column of datagrid have data from 2 row of datatable
I am new to vb.net and I am trying to query a database and print out the records in the row to the console window. I got it to work, but I have a feeling that there is a more concise way to do this. One thing that I am sure is wrong is that I had to convert the dataset to a datatable to be able to retrieve the values. Is that correct? Could you take a look at the code below (especially the for loop) and let me know what I can improve upon?
