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.
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?
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.
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).
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 ------- 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.
I 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'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]....
I 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."
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?
I have a chart control (stacked chart to be more precise) and a datatable that contains 3 columns. I want to bind them into a stacked bar chart. below is what the datatable looks like:
I would have the Resource column as the x-axis, and the value (hours worked) of each Queue as the y-axis (stacked)I've tried just binding normally and I'm getting an error saying that it's the wrong data type.
I have an object called Result<T> that has a constructor which accepts an argument of IEnumerable<T>. I'd like to be able to pass in a datatable if possible.
I tried datatable.AsEnumerable(), but where I bind to the data it was complaining that 'MyProperty' is not a field or property on type 'DataRow' - which makes sense since 'MyProperty' isn't a property on 'DataRow', but it was a column in my datatable.Is there a way to convert a datatable to something that I can pass into the Result object and still have it bind to, say, a gridview?
I have to generate an XML file from several database tables. I could use the WriteXml method of the DataSet to do it, but the database tables are really huge and I can't add all those tables in the DataSet at the same time or it may cause a problem because of the big amount of memory used. Then I decided to use the DataTable's WriteXml method and save table after table, but the the generated file only stores the information of the last DataTable.WriteXml's call. How can I preserve the previous XML data when adding all that information?
I need to save a datatable to a binary file , in binary format , in order to make the process fast because the datatable may contain up ten millions rows. So , XML is not favorable because it makes the file large sized , and the process will be slow.
I managed to save the datatable to a binary file , and it works fine , but the problem when I try to add new rows to the existing binary file (using a datatable with the same schema , but different rows data) , it copies the schema of the datatable to the binary file, making it very large.