Calculating Datatable Field?

Mar 15, 2012

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]....

ADVERTISEMENT

Loop Datatable And Select Checkboxlist Item Based On The Datatable Field Values

Aug 18, 2011

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].....

View 3 Replies View Related

Calculating Statistics Effeciently - Datatable Which Calculate Different Statistics For Different Subgroups

Dec 16, 2009

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:

View 1 Replies View Related

How To Get Value From Field In DataTable

Mar 15, 2009

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] .....

View 4 Replies View Related

C# - Getting Value From Field In DataTable When Column Name Has Spaces?

Mar 8, 2010

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 ?

View 1 Replies View Related

Have A Field In A Datatable (dt) That Can Be Integer Or NULL?

Mar 1, 2010

I have a field in a datatable (dt) that can be integer or NULL.

View 7 Replies View Related

How To Save Contents Of Field From Row In DataTable

May 27, 2010

I 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

View 2 Replies View Related

DataTable Field Type From SQLServer Table

Mar 5, 2009

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?

View 1 Replies View Related

Assign Several Field Values In A Datatable Into A Single Text Box?

Jul 9, 2009

I have this working for a single field in a text but im trying to add more than one fields data .[code]...

View 7 Replies View Related

VS 2008 Datatable - Select And Filtering Year On A Date Field

Aug 16, 2009

I 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 Replies View Related

Check If A Field In A Data Table Is Null Before Creating A Textbox Bound To That Field?

Feb 24, 2010

I 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 Replies View Related

Make Gridview Checkbox Field Update Boolean Field In Database?

Feb 7, 2011

There 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...

View 3 Replies View Related

Make Database Field A DateTime Field Currently Is Set To String?

Oct 5, 2010

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

View 1 Replies View Related

Rename Field Headings And Change The Field Type?

Jun 28, 2010

I am trying to edit a dbf table. I would like to be able to rename field headings and change the field type, ie string or dbl, and the size of the field. is this possible to do with vb.net. I have connected to the dbf file but after that am lost on what to do.

View 3 Replies View Related

VS 2005 Datatable Vs Dataview - Apply A Filter To The Defaultview.rowfilter Property Of That Datatable

Mar 15, 2010

I 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 Replies View Related

VS 2010 : System.ArgumentException Was Unhandled Message=DataTable 'get_item_list' Does Not Match To Any DataTable In Source

Apr 21, 2010

I 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)

View 6 Replies View Related

Datagridview Bound To A Datatable Setting Its Datasource Property To The Datatable

May 20, 2011

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

View 5 Replies View Related

Get Subset DataTable From Main DataTable, But Preserve Primary Key & RowErrors?

Apr 16, 2012

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]...

View 10 Replies View Related

VS 2010 Datatable - Summarize Multiple Occurrences Of An Item In A Datatable

Jun 5, 2012

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

View 15 Replies View Related

Assign A Populated Datatable's Columns To Another Empty Datatable?

May 28, 2007

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 Replies View Related

Creating DataTable And Copy Existing DataTable Schema?

Feb 17, 2011

I'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 Replies View Related

Getting Array Of Selected Datarows From A Datatable.select Into A Datatable?

Apr 8, 2009

I 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

View 1 Replies View Related

Loading The Contents Of DataTable Adapter Query Into A Datatable?

Nov 18, 2009

load the contents of a query from a dataTable Adapter into a datatable?

View 2 Replies View Related

Tableadapter.fill(datatable) Fills The Row That Was Not Added To The Datatable

Aug 6, 2010

I 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]....

View 5 Replies View Related

Calculating Bit Masks In VB?

Jan 7, 2009

I am trying to figure out how bitmasks are calculated in vb... I have the following constants and their bit values:

[Code]...

View 4 Replies View Related

Calculating Commission In VB?

Apr 1, 2011

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.

View 1 Replies View Related

Calculating GCF And Reducing

Jan 27, 2011

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 Replies View Related

Calculating Interest In .net?

Jul 27, 2009

I,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 Replies View Related

Calculating Next Working Day?

May 5, 2009

i 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]...

View 2 Replies View Related

Calculating Using Only One Button?

Aug 31, 2010

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 View Related

Code Is Not Calculating Right

Sep 21, 2010

Can someone help me figure out why my calculations do not come out right? I have many notes so it is easy to understand. The assignment is: "Create a windows app for the rental of a vehicle. User selects number of rental days up to 7 days. The user also 'can select one of three types of vehicles. Customer has a choice of filling the gas tank themselves,'or prepaying for a full tank of gas ($52). If vehicle will be driven by more than one driver, a multiple'driver cost of $22 per day will be added to the cost." [code]

View 4 Replies View Related

For Loop Is Not Calculating?

Dec 12, 2008

The interest is compounded monthly and these are sample inputs and output.

Input:
Monthly Deposit: 300
Annual rate: .05

[code].....

View 3 Replies View Related

Value Is Appending Rather Than Calculating?

Apr 6, 2010

I am trying to use and display calculations from various text fields, however it is appending the values. I think it has to do with it being a String Variable and not a Value.. here is the code

Private Sub btnTransact_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnTransact.Click
If rb1Deduct.Checked = True Then txtp1Amt.Text = (txtp1Amt.Text - txtTransact.Text)

[code].....

View 5 Replies View Related

Setting A Field Value When The Field Is Anonymous?

May 1, 2009

I need to set a field that i have dumped into a dictionary to a value that is always a string, (well, it came from an xmlElement, so the .value is a string)

Function setMembers(ByRef ClssObj As Object, ByRef nLinkObj as Object, ByRef xml As XElement) as integer
Dim fields As New Dictionary(Of String, FieldInfo)

[code].....

View 2 Replies View Related

.net - ImportRow From DataTable To Another And Still Destination DataTable Is Empty?

Apr 7, 2012

I'm trying to copy one row from DataTable to another, I looked almost everywhere and I can't find a reason why this is happening, I'm using ImportRow and still the New DataTable is empty. Here's one of the answers similar I found and It's still not working!:

Dim newTable As New DataTable
Dim dsFrom As New DataTable
For Each DBShoes In list
Dim iShoeID As Integer

[code]....

View 1 Replies View Related

Asp.net - Copy Data From Datatable To Dataset.datatable?

Oct 31, 2010

how to copy data from datatable to table in dataset i ry this but its readonly property

ds.datatable1=newdt.copy

View 1 Replies View Related

Asp.net - Looping Through Records From One DataTable And Populating Another DataTable In .net

Aug 10, 2011

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 ?

View 2 Replies View Related

Use A Datatable As A Data Source To Update A Second Datatable Using Sql?

Aug 10, 2011

I am updating a data table (dt_report_crypt) from an encrypted csv file in the code below:I decrypt the colums and update the same dreport_crypt, such that it will contain de-crypted data.This part is working wellI however need to use this de-crypted datatable as a data source to update a second table(dt_report), using the sql SELECT command to filter relevant data,

Dim dt_report As DataTable
Dim dt_report_crypt As DataTable
Using cn As 

[code].....

View 6 Replies View Related

VS 02/03 Datatable - Select Statement And It Will Go To A Datatable Object

Apr 4, 2011

I have a select statement and it will go to a datatable object, I would like to do the following

textbox1.text=datatable(first field value)
textbox2.text=datatable(second field value)
textbox3.text=datatable(third field value)

View 5 Replies View Related

VS 2008 Nesting A Datatable Inside A Datatable?

Mar 16, 2011

Is there a way to nest a datatable into another datatable? I know you can do this with gridviews but thats not what I'm looking for.

Also, I don't want to merge the datatables. What I'm trying to do is have a datatable with 2 columns and each column containing different datatables.

View 7 Replies View Related

.net - Calculating Yaw / Pitch / Roll

Mar 17, 2011

I have three GPS antennae on a boat. They are in fixed xyz positions relative to each other. For example:

[Code]....

View 2 Replies View Related

Calculating A Bill For A Dental Lab?

Feb 20, 2010

I am working on this program that is suppose to display the patient's bill after they have selected a service at a dental lab. the problem I am having is that if the patient name is empty it gives me a message but it still shows the bill. Also I am having a problem with the code that will calculate the bill if a a patient choose more than one service. Here is my code below

P
ublic Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSubmit.Click

[Code].....

View 4 Replies View Related

Calculating A DataGridView Column?

Apr 24, 2012

I have probably not a unique issue but I can't seem to figure it out. I need to calculate a datagridview column after it a new row has been added to it. I am adding the row to the datasource and the row is added to the datagridview but how can I automate the two thing together by a single button click. IE: add the row (with a value)to the gridview and then calculate. I have this code but is doesn't work.

Private Sub Button2_Click(sender As System.Object, e As System.EventArgs) Handles Button2.Click
Dim OwnerID As Integer

[code].....

View 3 Replies View Related

Calculating Age From Two DateTimePicker Tools?

Dec 24, 2011

I just want to calculate age from two datetimepicker tools. The label should display - "XX years XX months xx days old". I have succeeded in calculating with respect to time, but failing w.r.t date.

View 3 Replies View Related

Calculating An Average From Input?

Feb 8, 2009

here is my problem. i have to enter two grades, each grade should be an integer between 0 and 100 inclusive. Calculate the average of the two grades. If the average is greater than or equal to 90, display "Grade is an A!". It goes down the line for "if average is _______, display " ______is a/n __!" I get the last part and I know how to figure an average...but i am not sure how to type it in code. He did an elseif example, but it wasn't with 2 numbers and didn't have to average anything. So I don't know how to write that code....is there anywhere to look to find it? Here is what I have so far.............

Module Module1
Sub Main()
Dim grade, sum, average As Double

[code].....

View 14 Replies View Related

ADVERTISEMENT