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
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How can I check if a datatable has never been set ? or Null or Nothing ? I don't mean empty Datatable ... For example,
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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 RepliesI 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 Repliesi 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)
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
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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 RepliesI 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 Repliesi 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)
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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.
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.
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
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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 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")
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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)
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"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)
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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
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how to copy data from datatable to table in dataset i ry this but its readonly property
ds.datatable1=newdt.copy
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 ?
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
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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)
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.
I have a session which contains a datatable and also have a function which returns a datatable. I need to add these two. How can I do this? The below code is to be replaced with correct code.
Session("Table")=Session("Table")+obj.GetCustomer() where obj is an object of the business layer.
The '+' sign cannot be used to add these two, so how can I do this?
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 RepliesNot certain what exactly I am doing wrong here, but I am having problems in setting a new DataTable (for posting back to the database) to the Changes resulting from the Merge proc of 2 DataTables. The code works fine until I attempt to set the ChangesTable --- it always ends up = Nothing.What is strange is that the "preMergeCount" = 0 and the "postMergeCount" = 23, which is EXACTLY how I expect it to be! So I know that the Merge is working correctly.
Dim sqlTable As DataTable = dsMonitoring.Tables("SQL_SRTraps")
Dim exlTable As DataTable = dsMonitoring.Tables("Excel_SRTraps")
AddHandler sqlTable.RowChanged, AddressOf Row_Changed
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