I am having a problem trying to replace the missing values in my Dataset tables with a default string. The columns in my datatables should be all strings.Here's the code I am using, but I am getting the DBNull to string conversion error.
Code:
For i = 0 To MyDs.Tables(j).Columns.Count - 1
For k = 0 To MyTable.Rows.Count - 1
IIf(IsDBNull(Trim(MyDs.Tables(j).Rows(k)(i).Value)), "None", Trim(MyDs.Tables(j).Rows(k)(i).Value))
Next
Next
I'm having a hard time figuring out why my code will not produce a datatable with text.
VB
For Each line In Values
' Create rows collection using TableRow object to dynamically add rows
Dim tRow As New TableRow()
[code]....
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].....
Currently, I'm developing a project related to RFID which includes display data real time on screen. (I have a SQL Server 2005 express database. Once reader throw me a tag, I will go and pull the related information of this tag from DB and return to windows application.)One of the windows forms will display the tag data that has been read by the RFID Reader with related information. And I use DataTable to keep this data and on my form I have one GridView which datasource is point to this DataTable. (I have 10 readers which will throw me the tags that had been read and so data will come in simultaneously)
The problem is during reading and displaying information on grid, sometimes the datatable throw me an error of "DataTable internal index is corrupted: '5'".I found some post that said to use BeginInit, EndInit and Accept Changes.
I want to know is "Is there any solution that I can replace datatable with???"
I am trying to find a set of missing values between an array and cell values from a DataGridView. The array is a set of numbers from 1 to a user-entered maximum number. For example, if the user enters 10, then the array will have the values 1,2,3,4,5,6,7,8,9,10. The rows in the DataGridView might have values such as 2,4,6,8. I want to create a second array that would have the values 1,3,5,7,9,10. I believe I need to loop through the array values and compare them to the row values in the DataGridView. But I'm stuck on the method of either adding or removing values (or doing nothing) to the second array as the array value loops through the DataGridView. logic or some VB Code that will produce the results I'm looking for?
View 8 RepliesDim re As New Regex("((?<field>[^"",
]+)|""(?<field>([^""]|"""")+)"")((?<rowbreak>,
|
|
|$)|,)")
[Code] .....
Now it puts all the data in the correct columns but there's just a comma in the empty columns.
I've got two data tables with store numbers. I need to find out what store numbers are in one data table that arent in another.say one table A might look like:
34, 35, 39
the other table B may be
34, 35, 39, 45
I need to find the 45 If I use nested For Next I can get matches but anything not a match would show up not just the 45 value as the next progresses.
I am writing a program that basically "encrypts" any text file you put into it. All of my code works perfectly, but I need to know how to replace Enter and Tab values..How do you do this?I tried doing:
s2 = s2.Replace("(Chr(10), "{123}")
But that doesn't work.
i have a string which is a paragraph written on the aspx side. So its goes like this.
The new student, {student_name} has the following grades -
Maths - {math_grade}
Science - {Science_grade}
[code].....
I have a String array with the following values[code]...
what i need is a loop or something to replace the values as such[code]...
I then need to add another index to the strArray() which will hold the last value ie[code]...
I have list of about 100 names in first columns. and i have list of same people's names in second columns, but both are not same.
[Code]...
If you notice carefully, all five people in column A have their names in column B as well.I need somehow both column showing same names for same people ignoring extra names like Jones,
Been trying to get somewhere with this in another thread, but no such look, just keep getting reffered back to the same documentation... If I understood the documentation, I would have fixed it by now:
vb.net
Private Sub MakeiSuitePwdFile()
Dim text As String =
[code].....
I have the String and integers to which some values are assigned. now i need to read the string and integer values and assigned them to the datatable which i have created using VB.Net.
[Code]...
I have an application in which I have two text boxes in which I enter name and age, after I enter the name and age then I click the Add button when I click the add button then the Name and the age should be displayed on the Datagrid contol in the same application. But the data should not get saved in the Database, it should just show the data on the Datagrid contol. And they have told me that its mandatory that I have to use the DataTable object.
And when i click the Commit Changes then only the data should get saved to the Data base...This i can do .
Here is my code
Dim dt As DataTable = New DataTable("Intervenant")
For Each column As DataControlField In grdvIntervenants.Columns
dt.Columns.Add(New DataColumn(column.HeaderText))
Next
[code]....
I am developing in ASP.NET using VB.NET as background code. I am on vs2008 with windows 7 enterprise edition.I have just restarted doing VB.Net and my first time using a gridview without a DataBase, so maybe I am missing something. Basically, I am trying to add a DataRow (dr) to a DataTable (dt) and then put said DataTable into a Gridview (grdvIntervenants).My first step is to take the gridview and put all its data into a DataTable. Then i create a DataRow(dr) that I populate with variables and I add said DataRow to the DataTable. After that, I put the DataTable as the DataSource and bind the GridView.
The problem is that my GridView shows the rows but they are empty.While debugging, I found out that this error was beside all the DataRow.Item:"In order to evaluate an indexed property, the property must be qualified and the arguments must be explicitly supplied by the user" Seraching for it on the net.I did not totally understand the error, so i tried many different ways of adding the data into the DataRow but to no avail. I also tried different way of adding the column thinking the index problem might be coming from there, but again, the problem persisted. Now, something I found weird was that the Item property of my DataRow gives the quoted error, but I see the values into the ItemArray of the DataRow.I also found out that the same error appears beside the columns property into the dataTable.When I try to access the data from the DataSource in my rowDatabound method using the DataBinder, it gives me null results...
Im working on an Asp.net / VB.net website and coming from a C# / WPF background things are still a little new to me. I have declared a DataTable like so: Public notificationList As DataTable And I have then used the Page_Load event handler to populate it and bind it to a control on my page, which all works fine
[Code]....
However in another method i need to be able to access this DataTable, yet whenever I do it always appears as nothing. Do I need to be storing this value elsewhere like in the session etc?
I have two datatables in which I query out the required data.Both has one comman column LOTNUM.
1st table LOTNUM and EXPECTEDRETURNDATE, FLAG(default="open")
2nd table LOTNUM and ACTUALRETURNDATE
I want to compare
if ACTUALRETURNDATE<EXPECTEDRETURNDATE
then
Change the value of
table1.FLAG= "CLosed"
else nothing
I want to do that for all the values that are there in table 1.So table 2 is just like a reference table to compare its date with.
Dim cmd2 As New SqlCommand
cmd2.Connection = con
cmd2.CommandType = CommandType.Text
[code]....
I have two data tables. dtAllResults is the master data table which contains ResultIDs and everything related to each ResultID. dtNoCV is the other data table which only contains ResultIDs. If the ResultID from dtNoCV is located in dtAllResults I want to update some checkbox cells in dtAllResults (as seen below).
I'm looking for better performance, because dtNoCV may contain a few hundred ResultIDs and I'm afraid this loop will slow things down.
Private Function prvfnc_UpdateDGVSource(ByRef dtAllResults As DataTable, ByVal dtNoCV As DataTable, ByVal intEnumValue As Integer) As String
Try
[Code]....
I am trying to export a report but everytime it runs the code to export the crystal report in the crystalreportviewer I get an error message saying "Missing Parameter Values". I've looked through many sources but havent found a solution. I do know that all parameters are filled in because without the export code, the site runs perfectly fine.
Export code
Try
Dim CrExportOptions As CrystalDecisions.Shared.ExportOptions
[code].....
this is my datatable i want each value of a datetimepicker to view the data
dim booking_table as new datatable
booking_table.Columns.Add(
"Time", GetType(String))
[Code]....
I am using strongly typed dataset and have many tables in that. The problem is now I want to filter data from
GetData()
function which has a query like
select * from table_name
How can I filter a particular table and distinct values from it. Also if I try to filter it return all column but rest have null values except the one I asked, so I cannot assign it as a datasource to a datagrid or combobox. How can I do this..
I want to loop through a databale and change the values of a specific column in that datatable.eg: the database returns Request_ID, Desc, Date and Status_Ind. The Status_Ind column contains integer values. I dont want to show the integer values to the user. I want to convert that to a string value based on the integer values returned in that columns.
View 2 RepliesI want to fill a combobox with the values that I have in a datatable. How can I do that? Below is the code for the population of the datatable:
[Code]...
I have a datatable called dt which includes a column called type.I have a string array called typestringarray with about 15 members
I want to create a new datatable from the rows where type is a member of typestringarray[code]...
I am not getting any errors but the values of data table is not being inserted either
I have declared Public
Public x As Int16 = 0
Public table As New DataTable
[code].....
I have a datatable contain fId field. I want to update all values for this field to "1" without using loop. [Code]
View 1 RepliesI have a "result" which is DataTable and I like to get the x distinct values(City) and convert it back to DataTable how do I do this the code below gives me an error
Dim query = (From x In results.AsEnumerable()
Select (x.Field(Of String)("City"))).Distinct().CopyToDataTable()
so what I want is records of distinct cities I can get that but the problem I am having is converting it back to Datable.
Edited:I am using "where" in this statement and it does convert to Table(works fine) but not on "select"
Dim results = (From myRow In ds.Tables(1).AsEnumerable()
Where (myRow.Field(Of String)("xxxx") = xxxx)
Select myRow).Distinct().CopyToDataTable()
I have a DataTable that has several hundred rows.I want to get a row count of distinct values in a particular column.For example, I have a DataTable of Product Orders, but I want to get the number of unique Customers.
I was using this code, but I can't rely on it because my binding source is filtered from time to time.If my binding source has filtered out all rows datatable.DefaultView returns 0 rows.
I have a datatable which has been dynamically generated from FoxPro tables using a UNION Select statement. e.g.SELECT * FROM x UNION SELECT * FROM y UNION SELECT * FROM Z ORDER By v_alue1This produces a datatable with about 100 rows, each containing many fields, one of which is c_olor. From this datatable, I would like to select the distinct colors and then output in a dropdown.I have a public class Color which just has one property which I can then use as the DataTextField and DataValueField for the dropdownlist
Public Class Color
Private _c_olor As String
Public Property c_olor() As String
[code].....
Is it possible to store color values in a data table? Such that when these values are loaded into a datagrid, the datagrid will display the color.
View 2 Replies