Reading Excel In .NET - Some Columns Are Read In As Null?
Sep 27, 2009Reading Excel in .NET - some columns are read in as null
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.net - NULL Values Reading From Excel File?
Mar 4, 2010i am not getting the integer values in dataset while reading from an excel files the field which is integer will be showing as NULL.
View 1 RepliesExcel Reading - How To Ignore Hidden Columns
Aug 12, 2009I am reading XLS files, via JET provider, using the following
Dim conString As String = "Provider=Microsoft.Jet.OleDb.4.0;data source=" + fileName + ";Extended Properties=""Excel 8.0;HDR=Yes;IMEX=1;"""
cn = New OleDbConnection(conString)
cn.Open()
da = New OleDbDataAdapter("SELECT * FROM [" & sheetname & "]", cn)
da.Fill(dt)
The problem I am facing now is that some of these excel files have hidden columns: These columns are meant to be ignored. However, the code above fills my datatable with ALL columns (hidden and nothidden). Is there any "Extended Property" that I could add to the connection string, to ignore hidden columns?
VS 2010 Reading Excel Returns Some Rows As Null
Oct 25, 2011I have a vb.net app that I can read a .xls file into a dataset or loop through as oledbdatareader and it gives the same result.Some of the rows have all nulls when I loop through them but if I open the same file in Microsoft Excel I can see that row fine.[code]From the info above the first two SKU values would come through fine but when I get to the 3rd row it would show a null.Is it possible that it kind of inherits the first rows type and since the 3rd row isn't all numeric if nulls it? [code]
View 1 RepliesReading Excel File With Gembox - Columns.Count = 0?
Sep 1, 2011im usinf Gembox to read Excel files.I'm copying the fields to a datatable, so i have to add the columns to the datatable first.
Therefor im using this code:
For i As Integer = 0 To objWorksheet.Columns.Count - 1
objDataTable.Columns.Add(i, GetType(ExcelCell))
Next
But objWorksheet.Columns.Count is 0 even if theres data in 4 columns.
Reading Excel Into DataGridView And Typing The Data Columns VB 2010?
Sep 5, 2011In my application I read data (using data binding) from an Excel spreadsheet into a DataGridView. This works, but the data columns contain text fields (strings). I would like to set the data type for some columns to "Date" and Decimal. I cant do this on the DataGridView (error: cant change properties for data-bound stuff) and I cant figure out how to do it on the dataset or data-table that I bind to the DataGridView.The following is the code I use to read and bind the data:
Using con As OleDbConnection = New OleDbConnection(cs)
'
'open the OleDbConnection
[code]....
The commented out code (below the 'Todo: comment) causes a additional table, but I want to change the table with the data.
Code Read The Excel Cell As Null When It Contains Data?
Mar 29, 2012Using VB.Net, I am reading an Excel spreadsheet does anyone know what might cause a cell to be read as VBNull when it contains data?the cell clearly contains data. and what is extra weird is all the same cells in the rows before and after the bad one have the little green triangle in the upper left corner, indicating an error - but they all read fine the cell that reads as NULL is the cell in row 4 above
View 1 RepliesOpen - Edit - Read Excel File Columns?
Sep 23, 2009How do I open, edit, read excel columns in vb.net? Like, for example, I want to know the values of column B up to the cell that it contains values.
View 1 RepliesReading A Blank String From Excel When Trying To Read The Header Of A Data Column?
Aug 25, 2011I use an OLEDB connection to read from an excel database, and this loop to read in all of the data from each of the columns
While reader.Read()
For i As Integer = 0 To reader.FieldCount - 1
temp = reader(i).ToString + ControlChars.Tab
output_file.Write(temp)
[code]....
Some of the columns contain date information, which are read in fine (usually as a string "2/20/2011" or so), but the headers of those columns are read in as a blank "". The headers for all the other columns read in fine, but not for the date containing columns.
Using A Loop Condition To Check If There Is Null Value In The Columns?
Feb 15, 2010I'm using a loop condition to check if there is null value in the columns, then remove it.
-Original author
[STart:]
For i As Integer = counter To dt1.Columns.Count - 1
For x As Integer = 0 To dt1.Rows.Count - 1
if some condition then
something = true
[Code]...
Sometimes it runs correctly and sometimes even though when i becomes greater than (dt.columns.count - 1), it still executes the for loop and throws an error that there is no column with that index. I must be missing something here but I'm not able to debug the issue.
TableAdapter.Update(...) Inserts NULL Values In All Columns For A New Record?
Oct 22, 2009TableAdapter.Update(...) Inserts NULL Values in all columns for a new record?
View 4 RepliesC# - Joint Query In Linq To SQL To Select All Records Even There Are Some Null In The Columns Of Foreign Keys?
Feb 2, 2011I'd like to take all suggestion either in C# or VB.NET.I have a DB diagram like the image below. I also include the database script here [URL]In the Students table, CountryId and RoomId column are allowed null. Because some records do not have info about room and country yet.Also, some students do not have essays.I'm doing a joint query with all tables. I want to select all students to project the result like this:Wanted query result.
Here's my current query that gives the result like the image below:
Dim db As New DBDataContext
Dim query = From st In db.Students _
Join c In db.Countries On c.Id Equals st.Id _
Join r In db.Rooms On r.Id Equals st.RoomId _
[code].....
current query result I got only one result back because I have (2) William NoMan record in every table. But I don't get anything about others, like (3) Sync Master who has everything but RoomId.What do I need to modify the query above so it will give me all students like in the wanted query image above?
Reading Excel Files In Vb.net Leaves Excel Process Hanging?
Oct 23, 2009The following code works fine but seems to leave instances of excel.exe running in the background. How do I go about closing out this sub properly?
Private Sub ReadExcel(ByVal childform As Fone_Builder_Delux.frmData, ByVal FileName As String)
' In progress
childform.sampleloaded = False
[code]....
CSV Reading Using Jet.OLEDB4.0 Null Value When There Is # Character?
Oct 4, 2011This is my Connection String :
cn.Open("Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" & PathtoTextFile & ";" + "Extended Properties=""text;HDR=YES;FMT=Delimited""")
[code].....
Getting Null Reference While Reading From A Cell
Nov 21, 2011I'm having this exception while trying to get the value of a cell from a table.[code]...
View 2 RepliesReading A Null Terminated Byte?
Mar 29, 2011I'm reading a binary file. Apparently its older, and some of its values are based not on position, but on null terminated bytes. Position 17 thru 35 represents a value, however, if their is a null byte at 30, then you get garbage if you try to read 17 thru 35 as a value...
I need to read, specifically, from 17 to 29 in this instance because pos 30 is a null byte.
Have to read it byte by byte, no problem. Not sure though the syntax of comparing a null byte specifically.
If you need a sample of the binary file, I can post it.
.net Reading From ListViews With Multiple Columns?
May 17, 2010how to read from the first column but I need to read from both of them. I am using full row select which I need on there.Here is the code I am using to get it for the first column.
Dim I As Integer
For I = 0 To ListView1.SelectedItems.Count - 1
MsgBox(ListView1.SelectedItems(I).Text)
Next
Ignore Null Characters (chr(0)) Upon Reading A File?
Aug 13, 2010So I want my program to read a file, but sadly there are null characters in the text file. The program searches for strings and I want it, when searching, to ignore all of the null values and just the actual characters. Is this possible?
View 4 RepliesReading In And Performing Calculations To Columns Of A CSV File
Apr 25, 2012I haven't used VB in 2 years and have forgetten way too much, but I still understand quite a bit. I just can't synthesize it.
Anyways, here is what I am struggling to do.
I have a CSV file as formatted in the screenshot at this link:[URL]
Number of rows can change but the number of columns won't.
I need to:
1:read in a csv file
2:take the second column save the first and last number as a variables for computations (these numbers will be the smallest and largest numbers, respectively if that makes it easier to program)
3:put into the first column of a new array the following computations based on the 2nd column from the csv file computation=((array value-first number)/(last number-first number)*100)
4:add to first column the same computations again but +100 i.e. if the first row had a cell that had computed to 1 then the next number would be 101
5:add to first column again the same computations again but with an addition +100 (+200 total) this should cause the column to have numbers between 0 and 300
6:write column 3 of array to 2nd column of the new array
7:write column 4 of array to the end of 2nd column of the new array
8:write column 5 of array to the end of 2nd column of the new array
9:delete excess array space
10:write new array to txt file with delimiter of " " (a tab) with the same name as the previous file
I have been looking at this for 6 hours now and although I figured out how to read in a csv file, I was not able to figure out how to call up the individual values for computations.
I won't complain if you give me code but what I really want is an understanding of what I need to do to accomplish this.
FileGet Stops Reading Binary File At First Null (0) Byte?
Dec 18, 2011I must search a binary string for a pattern. This worked fine in VB6 using Get to read a file into a string and using InStr to search for the pattern. The conversion from VB6 to VB.NET changed Get to FileGet and warned of new behavior, but I don't see anything in the FileGet documentation about not being able to read 0 value bytes.
I don't mind at all changing to a new method, but ultimately I must get the data into a string rather than an array.
[Code]...
Read Excel Data (Excel 2007 SP1, On Windows XP SP3) With .net 2008?
Oct 7, 2009I am trying to read excel data (Excel 2007 SP1, on Windows XP SP3) with visual basic .net 2008 (VB 9.0 SP1). I have tried several attempts and whatever I do I am getting the following error message: System.Runtime.InteropServices.COMException was unhandled ErrorCode=-2147319784 Message="Altes Format oder ungültige Typbibliothek. (Exception from HRESULT: 0x80028018 (TYPE_E_INVDATAREAD))" Source="Microsoft.Office.Interop.Excel" Message="Altes Format oder ungültige Typbibliothek." Translated: Old format or unknown type libraryI have added the reference "Microsoft Excel 12.0 Object Library" to my project. I am assuming that I might have to add a different or an additional reference, but I do not have any clue which one to use. List of things I have already done:- Searched other forums- Altered the language settings- Tried it on an other Computer (Win XP SP3, Excel 2007, Visual Basic 2008 Express)- Ran the diagnostics tool in Excel - Updated all updates etc...- Reinstalled Visual BasicI really do not have any clue why it should not work?
Imports excel = Microsoft.Office.Interop.Excel
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim xlsApp As excel.Application
[code]....
VS 2008 : Use Code To Read Excel File With Excel Installed?
Feb 7, 2012I am uploading an excel file to my app and want to read it. Do I need to have excel loaded to read this?I am getting an error of Object reference not set to an instance of an object.
Public Function GetExcelData(ByVal ExcelFilePath As String) As DataTable
Try
Dim OledbConnectionString As String = String.Empty
[code]....
OleDb Jet Cant Read More Then 256 Columns?
Dec 12, 2009builder("Provider") = "Microsoft.Jet.OLEDB.4.0"
builder("Data Source") = IO.Path.GetDirectoryName(Me.OpenFileDialog1.FileName)
builder("extended properties") = "text;HDR=Yes;FMT=Delimited;"
I am using this to connect to a textfile database, but ti wont read over 256 columns like excel. Is there any kind of work around short of changing my database file which isnt an option
Read In Only The First 2 Columns Of A Txt File?
Aug 11, 2011I'm trying to read in only the first 2 columns of a txt file into 2 lists but am having problems getting the split function working. When I read the file the first strfields = "5.000 300.000" and the second strfield falls over.
Samples text:
0.000 300.000
5.000 300.000
10.000 300.000
[Code].....
Read DataReader Null Value In To Textbox?
May 18, 2010What i want to do is to read a value either null or not null from my oracle database using DataReader and store in a textbox. But i have an error.InvalidOperationExcepionHow can i avoid this error.Or is it possible to catch the exception to ignore null values read by the datareader?If the option is to catch the exception how may i do it?
Dim Dr1 As OleDb.OleDbDataReader = Cmd3.ExecuteReader
Dr1.Read()
lect_name = Dr1.GetValue(1).ToString
[code].....
DB/Reporting :: Read Excel File Without Excel Installed Using VB?
Feb 27, 2012I tried to read excel file using the method i found here [URL] But i get an error on ADODB.Connection saying "Type 'ADODB.Connection' is not defined" in the following code:
Code:
Private Function GetExcelConnection(ByVal Path As String, _
Optional ByVal Headers As Boolean = True) As Connection
Dim strConn As String
[Code]....
Its was used in VB6... do i need to do something special in Visual Studio 2010?
Excel Values Become Null ?
Oct 15, 2009I'm trying to import my xls files to sql server, but i saw some values become null even though data in excel values are exist.
below is my connection string :
Code:
Dim cnstr As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=" & txtfName.Text & ";" & _
"Extended Properties =""Excel 8.0;HDR=YES;IMEX=1"""[code].....
This error occurs while i'm importing the alphanumeric values into text, but previous values are numeric (but string datatyped).
Read A Text File's Columns?
Jun 17, 2009Essentially my program asks the user for their name and a number, and it stores both values in a text file. However, when retrieving the code from a particular line it cannot separate the number from the person's name.will I have to use a new line for every entry, or is there some way to tell my program to differentiate between columns in the code?
[code]....
[2008] Read Only Columns In DatagridVeiw?
Feb 13, 2009I want a Database read only and shown up in a datagridveiw without the user being able to edit the data into a certain column.Example i have a Database:
*In my Column is "ID","Name"
*Then in my Rows is "Ryan",Mark"
How can i display these data into in datagridveiw.....Cause i want to create a displaying records in datagridveiw..
Re-arranging Columns In Excel?
Sep 26, 2011Is it possible to take an Excel spreadsheet and move some columns around? Basically I receive spreadsheets that need to be re-formatted and have the columns shifted, some also need to be deleted. I have no idea how to go about this, is it even possible? It's always the same columns so it's not like it changes from file to file. I know it probably makes more sense to just create a macro but I thought I'd see what was involved in it anyway.
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