I'm having some problems calculating the values for two diferent fiels of the datatable. it return " Object reference not set to an instance of an object"this is How I feed the datatable
Dim daProd As New SqlDataAdapter
Dim conProd As New SqlConnection
conProd = Connect()
Dim cmdProd, cmdSave As New SqlCommand
[code]....
I am trying to display value of the field ("UserID") for every row exists in datatable to checkboxlist(make the checkboxlist item selected).
I used for loop, but only the field value from last row of RoleUsers table is selected in the checkboxlist.
Here is my code
Private Sub DisplayRoleUser()
Dim conn As SqlConnection
Dim cmd As SqlCommand
[Code].....
In one of my programs I have a datatable on which i calculate different statistics for different subgroups. In my opinion this is as very timeconsuming proces (at least my solution). I was wondering if there is not a more effecient solution.
CODE:
I am trying to use the value of a field of the last row in a table. I have been trying to use tables().Rows().Item() but somehow it always returns the value of the first row instead of the last one. here is the code:
Dim accion As String
Label1.Text = ""
Label2.Text = ""
Label3.Text = ""
Me.HorasTableAdapter.Fill(Me.ControlDataSet.Horas)
[Code] .....
I have tried:
ObjDTOleDBNFeIntegra.Rows(I)("[Cnpj Cpf]").ToString() //with brackets
ObjDTOleDBNFeIntegra.Rows(I)("'Cnpj Cpf'").ToString() //with apostrophe
ObjDTOleDBNFeIntegra.Rows(I)("Cnpj Cpf").ToString() //without anything
I'm using VB.NET, but comments with apostrophes in here don't seem to be identified.And I get the exceptions for each case:
Column '[Cnpj Cpf]' does not belong to table Table. (fail)
Column 'Cnpj Cpf' does not belong to table Table. (fail)
Column ''Cnpj Cpf'' does not belong to table Table. (fail)
What should I do in order to ger a value from a field in a dataTable when the column name has spaces ?
I have a field in a datatable (dt) that can be integer or NULL.
View 7 RepliesI have a "For
Each
Row As
System.Data.DataRow
In
DataTable.Rows" type loop. I want to save the contents of a field to use in subsequent processing.
It looks to me like the proper way would be to use something like the following:
Dim saveCatalogWorkID As VariantType
For Each clsWTRow As System.Data.DataRow In clsWTDataTable.Rows
saveCatalogWorkID = clsWTRow.Field("CatalogWorkID")
Next clsWTRow
If the field type in the SQLServer db is 'nvarchar 10', what would be / is the field type in a DataTable filled by rows from this SQLServer table? String?
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View 7 RepliesI need to use .Select and filtering year on a date field,how can this be done,the next code give me error : the expression contains undefined function call year() vb.net For Each wRwTmp As DataRow In wTblC.Select("year(start_date)=" + wYear.ToString)Next
View 11 RepliesI am building a data based application using VB 2008 an SQL Express. I need to create textboxes on my form using code, (With & End With) method. I need a simple code string that will allow the app to check if the field to wich the textbox wil be databound is Nul, If so the textbox will not be created.
View 8 RepliesThere are lots of questions about this but I've not been able to solve my problem using the answers to any of them (after many, many attempts..)
I'm working in vb.net creating an asp.net web application. I have an SqlDataSource and a GridView on my page.
I want to change the DoNotMail boolean value represented by a Gridview checkbox and automatically update in the database if the checkbox is checked from 0 (False, Will Mail) to 1 (True, Won't Mail) here is the code I used. [code]...
is it possible to do a two way sync on the entire gridview when the user hits a button so you don't have to do an update every time a row is changed? because the user might check the box and then check another box then uncheck a box and it would be a lot of updates...
Dim query as String = "Select * from openquery (devbook, 'SELECT wb.arrival_time FROM web_bookings wb ')"All I need is to convert my arrival_time into a datetime field in the query
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View 3 RepliesI have a datatable and I apply a filter to the defaultview.rowfilter property of that datatable. If I then loop through the rows collection of the datatable, will I only be able to see those rows that the filter applies to, or will it loop through all the rows?
View 6 RepliesI am working on a project that takes an xml schema and xml data files and places them into a DataTable, the 2 files are generated from a working table that i have written to disk. I wish to load these 2 files into a DataTable. Here is What i have
vb.net
Friend Function CreateTable(ByVal tableName As String) As Boolean
Dim table As New DataTable(tableName)
table.ReadXmlSchema(tableName & ".xsd")
[code]....
this however produces the following error on line 3
Quote:
System.ArgumentException was unhandled Message=DataTable 'get_item_list' does not match to any DataTable in source.
get_item_list is the parameter passed into this function (tableName)
I have a datagridview bound to a datatable setting its datasource property to the datatable. I would like to have a child form that contains a list of columns associated with the datatable that contains a checkbox that will allow the user to hide and show the columns ( I do not know the best control to use here) (I assume this is the easy part as All i need to do is loop through each of the datatable's columns to get the column name)
now I would like save these visible columns on some event like form_closing so that the next time the user opens the form up it will remember the settings
I came across a problem with using a BindingSource as my DataGridViews.DataSource. Whenever I applied a filter to a column in the BindingSource and the user makes changes that don't match the column filter the DataGridViewRows would automatically disappear. A similar thing would happen when applying a Sort to a column. If the user made any changes the DridGirdViewRows would automatically sort causing rows to be moved around. This was not ideal for my application and there isn't anyway to stop this from happening with the BindingSource.
To correct this issue I have to use subsets of data. I use a DataView to apply the filter and sort to the main DataTable, which creates the subset DataTable.The problem is when I use the DataView.ToTable method I loose the Primary Key and RowError information. So I have to reapply this information everytime the user filters or sorts the DataGridView.Is there a better way to get a subset DataTable?[code]...
I have a datatable that has a resource in one field and hours used in another, it looks like this -
Resource Hours Used
Manager 1
Accountant 1
Field Staff 2
Accountant 3
Manager 4
Manager 1
Administrator 6
Field Staff 4
Manager 0.5
Administrator 1
What I want to do is be able to create a summary of the data table above that groups multiple occurrences of a resource and adds up the hours used for that resource, creating a summary that looks like this -
Resource Hours Used
Manager 6.5
Accountant 4
Field Staff 6
Administrator 7
Is there a simple way to assign a populated datatable's columns to another empty datatable? That is, I want to copy a datatable's structure only but not its data.
View 6 RepliesI'm using vb.net 2010.I have a DataSet with a Table and data. MyDataSet1 which contains Table1 I want to create another table that is the same as the Table1 but without data, but it should have the columns, etc.
View 1 RepliesI am getting array of selected datarows from a datatable.select.I use the commands below to get that array or datarows
Dim foundRows() As DataRow
strExpression =
Here is what I tried.I have looked at examples by MS but they all just write to the screen and I have no interest in that.
For Each rowWork In foundRows
dtWork.Rows.Add(rowWork)
Next[code]....
"LineOfBusiness = 'CPP'"
foundRows = modXchange.pdtWork.Select(strExpression)
Now, I want to place the rows from foundrows into an empty data table.I did what I thought was the obvious but that only returns a bunch of rows with no data
load the contents of a query from a dataTable Adapter into a datatable?
View 2 RepliesI am trying to add NewRow to the database by using datatable in dataset, but before I do that I want to make sure that row is not already there. I create new row for the datatable I am working with, fill it with information. I fill datatable with the row from database that has the same primary key as my NewRow by using tableadapter.fill method, but when I do that my NewRow that was never added to the datatable is filled with information from database(and not information that I assigned to it). I count rows in my datatable before I fill it and it's 0, so why is my NewRow affected by Fill command? (I am using VB.NET 2005 Framework 2.0)
[Code]....
I am trying to figure out how bitmasks are calculated in vb... I have the following constants and their bit values:
[Code]...
I'm really new to VB. This is only the 3 app I've created, and I'm stuck.I need to code an app that displays total commission earned on sales at different levels. The commission percentage goes up as sales go up.
Should I write a If/else/else/else/else/then statement or something else?There are 5 different commission levels in the problem. I have my interface designed, but obviously that's the easy part.
I understand the basics of using VB.NET, what I don't understand is what I need to tell the computer to do. I'm supposed to create a subprogram to calculate the greatest common factor and another subprogram to reduce the fraction from the answers retrieved from the first subprogram. My teacher said something about using Mod to calculate it, and also attempted and failed to explain ByVal and ByRef parameters. I don't even know where to begin other than the parameters I have for each, and even those have a high chance of being completely wrong.[code]
View 1 RepliesI,ve completed a program for a debt solution agency that calculates the amount a client can afford to repay after all his deductions and general life costs, my proplam however is at the end when i have to display all the creditors on a proposal data grid that shows the amount and total months to repay all creditors and calculates the amounts as one of the creditors debt is paid up and that monthly installment is devided between the remaining creditors.
View 1 Repliesi have the code below and i want to calculate the next working day adding five days from today and it must not add weekends as a working day. this code currently adds weekends as well and i need it tofclaculate excluding weekends.
[Code]...
I have a project that I'm working on and we are basically creating a calculator to calculate area of a rectangle and area of a circle using one button. How do I code to allow the button to calculate both the area of the rectangle and the
View 16 Replies