VS 2010 Check Whether A DataTable Is Populated?
May 15, 2012
i defined a list of DataTables
Dim PreSubTables As New List(Of DataTable)()
Then I parse some source files and depending on the data, possibly none of the tables in the list PreSubTables2 might be populated, so it's just an empty list. Later on when i refer to the first table in the list , I get "index out of range error"
If (PreSubTables(0).Rows.Count > 0) Then ...
' just dealing with the first table: PreSubtables(0)
For ii = 0 To (PreSubTables(0).Rows.Count - 1)
[Code]....
I'm just trying to come up with a line that checks whether the(at least the first)Table in the list is populated, before I can print it out or do other things.
View 2 Replies
ADVERTISEMENT
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
Nov 24, 2010
I am fairly inexperienced with using datatables in VB. My question is this: Can I access a particular column of a table by name if it is not defined elsewhere like when I populate a datatable using sqldataadapter.
[Code]...
Is this the way it can be done? I believe this is the case, but can't find any definitive examples online (probably not searching properly)
View 7 Replies
Apr 16, 2010
I'm having some trouble trying to export a datatable to Access. I've built an Access DB and Table identical to the datatable that I'm trying to export using ADOX.Now using and OLEDB connection I'm trying to populate that table. The following code works just fine in another app written in 2005 but not in 2008 for some reason.
Basically I'm bringing in the empty Access table into a dataset.Filling that table with the rows from the export datatable.Then running the dataadapter's update method to send the data to Access.The problem is the da_a.Update doesn't seem to work. No errors, the Access table just isn't being populated. I checked my before and after counts. I know that the datatable is being populated. It's just not landing in Access.
Dim conn_a As New OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & strFullFileName)
conn_a.Open()
'Select Access Table into new Dataset[code]....
View 4 Replies
Jan 28, 2011
VB2008 & mysql
Is it possible?
If so how?
Wanting to have multiple datagridviews showing unique information (via filters?) based on cell content all coming from one data table.
Example:
3 datagridviews accessing the same datatable that has a [Job Status] column limited to one of the following 3 entries NEW, JOBS IN PROGRESS or COMPLETED and having that column hidden from view on all gridviews
Top grid showing only NEW jobs
Middle grid showing only JOBS IN PROGRESS
Bottom grid showing only COMPLETED jobs
View 7 Replies
Feb 16, 2010
In a combobox populated by a DataTable I am having two issues!The SelectedIndex property will not set 1. Either by integer 2. Or by FindString
[code]...
View 3 Replies
May 15, 2012
I thought this would be an easy one but I can't think of a good way to do it.User submits a webform. Based on submitted information I build three classes and assign their properties from received data:
UserInfo userInfo = new UserInfo();
UserAddress userAddress = new UserAddress();
UserEmployer userEmployer = new UserEmployer();
Based on submitted information some classes end up being populated with properties and some do not.
What's the best way to check whether userInfo class, for example, ended up with properties assigned ? I don't want to save a particular object to the database if it doesn't have any real properties assigned and all of them are set to either null or "".
I only want to save the objects that ended up with at least one real property assigned.ps. using NHibernate to save data to db
View 4 Replies
Nov 10, 2010
I am creating a custom design for printing (RDLC)Is this possible to populate my rdlc from pre populated Dataset?I am populating my dataset like this
Private Sub populateExam()
Dim daClients As New SqlDataAdapter
Dim dsClients As New DataSet
[code]....
My Dataset hold only 1 record from my database.I need to pass that record into my cutomize page for printing.This is my layout. the red rectangle is the place for the values.
View 1 Replies
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
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
May 12, 2009
I have a function that search for a keyword and then return DataTable. I want to check if there rows inside because sometimes there's no query found.
'which one shoud I use ?
If dtDataTable Is Nothing Then
'some code
[Code]....
View 4 Replies
Apr 26, 2012
How can I check if a datatable has never been set ? or Null or Nothing ? I don't mean empty Datatable ... For example,
[Code]...
View 1 Replies
Mar 18, 2009
how to check if current row is new row in datatable?i'm trying to have some fields non-updataeble but can be inserted when it is a new record.
View 2 Replies
Jul 25, 2011
I use ADO.Net to call a stored procedure that retrieves data from our database.I put that data into a data table using this code below:' set Ready ResultIDs in databaseDim dt As New DataTabledt.Load(cmd.ExecuteReader)
View 3 Replies
Jun 4, 2011
i have a code where I dynamically generate the columns name and bind it it datatable. now I am iterating thru loop for each column and fill the datatable. My Problem is when I fill for first column row is already added to the position(e.g 0,1). if row at some position already exist in datatable I should not write
dr = dt.NewRow()
dt.Rows.Add(dr)
View 3 Replies
Mar 10, 2010
i getchanges from dataSet
when i am iterating through the rows I would like to check rowstate to see if row was added or modified. It says I cant check through an instance and the expression will be ignored..
Dim changes As New DataSet
changes = dsRates.GetChanges()
Dim count As Integer = 1
[Code].....
View 1 Replies
Apr 6, 2011
I have a datagridview that has a checkbox. That checkbox will designate if a day is a "Holiday" or not. When then user clicks on my save event, I want my sub to check to see if that box is checked and appending the data to a table in my database.
View 15 Replies
Apr 6, 2011
I have a datagridview that has a checkbox. That checkbox will designate if a day is a "Holiday" or not. When then user clicks on my save event, I want my sub to check to see if that box is checked and appending the data to a table in my database.
View 1 Replies
May 21, 2010
I have this code:Dim Result As New DataTable DataAdapter.Fill(Result)
'bind data to visible surname/name grid If Result.Rows.Count = 0 Then NoInputBottom.Text = "No Results. Please widen your search criteria and try again" NoInputTop.Text = "No Results. widen your search criteria and try again" Else
GV.DataSource = Result
GV.DataBind()
End If
I have also tried moving the check to the gridview like so:
If GV.Columns.Count = 0 Then
NoInputBottom.Text = "No Options Selected: Please select your search criteria and try again"
NoInputTop.Text = "No Options Selected: Please select your search criteria and try again"
End If
When I run the code. the noinput labels do not have value, the null check seems to be failing? Please can you tell me how to display a message if the search returned no reults.
View 1 Replies
Mar 26, 2012
this is my very first posting and I must say I am desperate. I have a VB assignment due in 2 days and I am so lost. I have written a code to draw some graphic, just a basic house, tree, sun etc. I have also written a code to magnify said graphics which were all the specifications of my Assignment 1 part A. Now for Part B I am being asked to extend my program so that: A - My graphic can be drawn using different colour schemes designed by me but chosen by the user B - My graphic or an appropriate part of it can be animated around the picture box if the user chooses to do so. C - Error checking is included.
[Code]....
View 2 Replies
Mar 24, 2011
I try to view a datagrid with one empty row in it when the form loads. The datagrid has to be bound to a datatable all the time.I get a NullReferenceException with the following
Dim dt As DataTable
dt = CType(Me.grdDataGrid1.DataSource, DataTable)
Dim newrow As DataRow = dt.NewRow()
newrow(0) = 1100
dt.Rows.Add(newrow)
The error occurs on the line where dt.NewRow() is used.The problem occurs when the datatable (and the datagrid) is empty. If they have data, this works ok.What do I have to do to get this to work with empty datagrids?
View 5 Replies
Mar 17, 2011
I have a DataGrid that a user is sorting, problem is that the sorted results are not being updated in my DataTable (which makes another function fail later). I have tried calling AcceptChanges() after the sort is done, but that isn't updating the DataTable. dtMessage.AcceptChanges()How can I have the DataTable updated after the sort to diplay what is displayed in the DataGrid ?
View 2 Replies
Sep 10, 2011
When I dispay data sets in a Datetable control. It started with showing the focus on first cell ( i.e. cell(0,0)). How can I set the initial focus to other cell (say cel(3,4))?
View 2 Replies
Dec 10, 2009
I have a listbox connected to a datatable. When i click a button, the marked item should get deleted. How?
View 5 Replies
May 19, 2011
I have a DataTable that I need to get a subset of into another DataTable to bind to a control. Is there an easy way to do this?
View 4 Replies
Mar 22, 2012
I have an sql database with multiple tables. I have been adding new columns to one of the tables as I need them, but now suddenly it has stopped allowing me to add columns.Everything works as usual until I add the 150th column to the table. When I drag the table from the server explorer to the dataset designer i get the following error:"Some updating commands could not be generated automatically. The database returned the following error: Dynamic SQL generation is not supported against a SelectCommand that does not return any base table information.If I remove the 150th column, everything works great. I tried using the wizard to regenerate the select and update statements, but it fails with the same error.
View 5 Replies
Mar 26, 2011
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 Replies
May 11, 2012
I have picturebox that the user can import an image, and then save it to the datatable. I can save it with no problem, and the image, which is a logo, will populate onto my crystal reports pages.My issue, is that I want the logo to automatically load into the picturebox when the user opens my settings form. How can I do the opposite of the following:
'set the company datatable for sub
Dim borrowersrow As PlannerFilesDataSet.CompanytableRow
'use only the first row
[code]....
View 3 Replies
Dec 10, 2009
Is it possible to add a Datatable to the project, add columns to it, and then add rows with data in it that i can use in my project?
I need to store some data in my program and i thought the best way was a datatable, but i also need to add some data that exists in it when i build my pogram.
View 14 Replies
Jul 20, 2010
I have an array which holds the following items
for example
Quote:
myArray(0) = (1)
myArray(1) = (4,2)
myArray(2) = (10,15,20)
[Code]....
and then am trying to add other column based on items available in myArray().
View 5 Replies
