I am getting this error cannot convert string to datatable
The code is
dt = CType(Session("result"), DataTable)
I am trying to store the session value in dt which is a datatable. The session result contains string values.how to convert the session to datatable and store the session value in the datatable.
data table contain column named as Fld_primary. this column contain value like 0.00 it is double datatype in mysql table.i want store that datatable value in double variable. am always getting error when i convert to double datatype.
my code
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Dim ds5 As dataset1.DTSUMDataTable = TA5.GetData(users)
Dim dttot As Double
dttot = CType(ds5("fld_primary").ToString, Double)
Error:Conversion from string "fld_primary" to type 'Integer' is not valid.
GPA 1.0, 1.1, 1.2 through 4.0 alredy entered in a listbox in propertiesradFemale, radMale, btnCalc btnExit: lblMale, lblFemale, lblAll to store averages. There are no text boxes.Please look at my code and tell me what I'm missing.... I'm sure it has something to do with the listbox...
Option Explicit On
Option Strict On
Option Infer Off
[code]....
In my fresh installation of Visual Studio Professional 2005 Visual Basic I have typed this code
dim olddate as date
olddate=datevalue("01-01-2006")
I receive an error: index out of range exception
On an other pc with the same fresh installation this do not happen. Why ? I have tried with other funtions : ctype, cdate but I receive the same error, while on an other pc this code is fine.
This question is based on VS 2008 using VB I have a detail Window form which is bound to a SQLServer table using a BindingSource &TableAdapter. The Table is mostly Text & Date fields with the Table Key has an Identity field
[Code]...
I have this code but the problem is that I get an error which says "Failed to convert parameter value from a String to a Int32." Here is the code that I am using:
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim conn As New OleDb.OleDbConnection
conn.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source = C:Documents and Settings1B09158My DocumentsUser.mdb"
conn.Open()
[CODE]...........................
I am finding difficulties to convert a datatable to a new datatable using a reference datatable. My question is confusing and I am not good at explaining things so I drew a picture (see below).I have two datatables on memory and I need to create the third datatable using the second mapping table for reference. The column names are just for example and it can't be hardcoded.
View 2 RepliesI am using two textBox's. The first to enter the data. The second to convert to answer the program complies with no error, the debugger cannot convert data type from string to double.
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why does the program not convert the textbox txtFahrenheit from string to double?
I tried many things but I always get "cannot convert string to membershipuser" from the ASP.Net MVC Membership Starter Kit
this line from file ListUsers.aspx
var users = (ViewData["Users"] as List<MembershipUser>);
ViewData["Users"] come from
public virtual ViewResult Index( int? pageIndex, int? pageSize )[code].....
I get the below error Unable to cast object of type 'System.String' to type 'System.Data.DataTable'.This is the code I'm using
Dim str As String = String.Empty
If (Session("Brief") IsNot Nothing) Then
Dim dt As DataTable = Session("Brief")
If (dt.Rows.Count > 0) Then
[code]....
I have read many posts on this topic; among them and most recently .NET - Convert Generic Collection to Data Table. Unfortunately, all to no avail.
I have a generic collection of structures :
Private Structure MyStruct
Dim sState as String
Dim lValue as Long
Dim iLayer as Integer
End Structure
Dim LOStates As New List(Of MyStruct) I need to fill a DataTable with this list of structures but have no idea how to go about doing this. I am using vb.net in Visual Studio 2008.
I'm trying to convert DataTable to Linq using
DIm result = From r in dt.AsEnumerable()
Select new ( col1 = r.Field<integer>("id"), col2 = r.Field<string>("desc"))
But i get error near 'new (' saying type expected.
I have seen many examples of populating a listview from a datatable or converting a datatable to a listview but what I am trying to do is exactly the other way around.
How can I convert/copy the contents of a winform listview to a datatable?
[EDIT]
I have a listview with a context menu where users can multiselect items and choose one of the context menu options, I then loop the selected items and extract each selected row (listview item) and serialize it, instead of doing this I wanted to convert the listview to a datatable then add the datatable to a dataset and serialize the dataset.
convert a dataTable to List(of T).In Vb.net on .Net 3.5 If you know How To or maybe a link of somebody who did it.I check this on c# (from another stack question)
public static IEnumerable<T> ToEnumerable<T>(DataTable dt, Func<DataRow, T> translator)
{
foreach(DataRow dr in dt.Rows)
{
[code]....
but I cant translate Func on .net 3.5?
I am trying to import a large array of integers stored as a csv file into a VB.Net DataTable called BeamMap. The .csv file consists only of integers, with a delimiter of ,, no quotes around the data (ie., 1,3,-2,44,1), and an end of line character of line feed and carriage return. All I want to do is get each integer into a DataTable cell with the appropriate rows and columns (there are the same number of columns for each row) and be able to reference it later on in my code. I really don't want anything more than absolutely necessary in the code (no titles, captions, headings, etc.), and I need it to be fairly efficient (the csv array is approx. ~1000 x ~1000).
View 2 RepliesI managed to Convert a Datagridview to Datatable, Now problem is the programmatically addded Columns Seem to end up at the end of the of the initial table layout[code]...
View 2 Repliesi am using following code to convert xml file to datatable but its just creating multiple tables (but without data) and i want tables with data..
Dim myDS As New DataSet
Dim xmlStream As System.IO.StreamReader = New System.IO.StreamReader(Server.MapPath("~xmldoc
esult_availhotel.xml"))[code].....
I have a question about converting a datareader to a datatable. In my code, I have a datareader created in one class and passed to another class that I want to convert it to a datatable.
When I do this, it does not seem to work, as the table remains empty. If I do the conversion in the same function, it works fine.
Its only when I pass the datareader to another function that it stops working. Is this because the dr is closed or something? How do I overcome this problem? Any help would be great.
I need to convert bindiangsource.datasource (which is a list) to dataset or datatable.
View 1 RepliesMay I know is there anyone did this before? I have the code below: Private Function FnReadWeeklyConsumption(ByVal pstrSheetName As String,
[Code]...
I want to be able to turn a datatable or dataset or the results of my SQL queries into JSON - purpose is for a WCF service which will not do it.
View 2 RepliesI have a relatively simple Listview that suddenly needs (due to new requirements) to have it's 'layout' extracted to a DataTable so that a common routine can convert it to an Excel spreadsheet for export purposes.The ItemTemplate is just a series of Table Rows with some text, data-bound labels and textboxes with validators in the cells.Usually, when trying to pull out a particular value (like what was entered into a text box), I use the ListViewItem's .FindControl method.
For Each objItem As ListViewItem In lvwOptions.Items
Dim objTextHrsLabor As TextBox = CType(objItem.FindControl("txtHrsOptByLabor"), TextBox)
decHours = CDec(objTextHrsLabor.Text)
Next
In this case, however, I'm trying to take all the data displayed - all the 'rows and columns' of the table that was created.Inside the ForEach / Next loop of ListViewItems, I started a ForEach/Next loop of Controls for each instance's controls but I got some really strange results returned (like controls that had a couple of table cells in them).
I get the sense I'm headed in the wrong direction. All I want is for the nicely-formatted 5-line, 6 column table to be converted to a 5-line, 6-column data table.
I'm using vb.net / winforms.How can I convert 10 lines with three columns into a DataSet/DataTable?
View 1 RepliesHow can i write this query with LINQ to a FoxPro database?SELECT count(*) FROM Table group by item1I wrote it as below, but it doesn't work
Dim Query
Dim dt As New DataTable
Dim da = New Odbc.OdbcDataAdapter("SELECT * FROM table1",connection)
[code].....
I've created a new access 2007 database + added a OLE Object field, that i've then pasted images into.in vb2008 I've connected to the database + put the table into a datatable. so far it works ok.when i try to convert the byte array to an image, it causes an error:
'A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll'heres the code i'm using[code]....
Using VB.NET, what is the most concise way to convert a single column of a DataTable to a CSV? The values are integers, so I don't need to worry about character escaping or encoding.
View 1 RepliesI need help with this line of code: Me.avgsalespricetxt.Text = Me.dtsold.Compute("AVG(Convert([Selling Price]),'System.Int32'))")
Here is all the code i have so far, I need to Average a column in my datatable from what i have read "Compute method supports expressions and they support CONVERT function that you could use inside of the expression."
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I am trying to convert my EnumerableRowCollection into a DataTable, but I can't see the CopyToDataTable method. The enm.CopyToDataTable() has the blue saw tooth line under it with error saying " 'CopyToDataTable' is not a member of 'System.Data.EnumerableRowCollection' ". I have set a Reference to System.Data, System.Data.Linq, and System.Data.DataSetExtensions. I thought the CopyToDataTable method was part of the System.Data.DataSetExtensions, right? Anyone know why I can't access this method?
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I'm pulling data from a D3 database, using an api.
The api can do the following: Dim OBJ As Object = mvsp.MVResultSetGetRows.ToArray()
But how do I get that data into a datatable to use as the datasource for a DataGridView?
i've created a new access 2007 database + added a OLE Object field, that i've then pasted images into.
in vb2008 i've connected to the database + put the table into a datatable. so far it works ok.
when i try to convert the byte array to an image, it causes an error:
'A first chance exception of type 'System.ArgumentException' occurred in System.Drawing.dll'
heres the code i'm using:
vb
Dim arr() As Byte = DirectCast(record.Item(5), Byte())
pic.Image = Image.FromStream(New IO.MemoryStream(arr))
its loading the byte array properly, but the Image.FromStream line causes the error. i've used this method before with an earlier access database + it works.