I am trying to export a dataset to a csv file
VB
Private Sub ExportDatasetToCsv(ByVal MyDataSet As DataSet)
Dim str As New StringBuilder
For Each dr As DataRow In MyDataSet
[code]....
I am getting an error on this line: For Each dr As DataRow In MyDataSet The error is Expression is of type 'System.Data.DataSet', which is not a collection type.
I am trying to perform a simple bound connection between an Access database and a text box on a form. This is actually Chapter 18 of the "Microsoft Visual Basic 2008" book.I get the same error message when trying to create my own project "MY ADO Form" or the "ADO Form" project supplied from the DVD provided with the book. I am running the 90 Day Trial Version of Visual Studio 2008 with SP1 and Net 3.5 SP1.
My operating system is the 64 bit Version of Vista with all updates.The error when I try to run the application in the debug mode is:"A first chance exception of type 'System.InvalidOperationException' occurred in System.Data.dll"and as a result no data shows up in the text box from the database and the data selection bar is grayed out in the form. The underlying database "Students Data Set" appears to be fine as I have seen the correct data for the fields "Instructor" and "PhoneNumber" prior to running the program and when connecting with the database.
My colleague gave me a DLL that manage all database business. I wanted to invoke a function that uses Stored Procedure and return the search result. In the function receive a parameter type in ystem.Data.IDataParameter[]. Below is my codes.
[Code]...
I have a function (on vb.net) to get a data from a XMLWebService:
[Code]...
I added this lines in the form load of DataGridPrinter by Merrion in the codebank..[code]Unable to cast object of type 'System.Data.DataViewManager' to type 'System.Data.DataTable'.
View 2 Repliesevery time i run this code i get the same error
Unable to cast object of type 'System.Data.DataTable' to type 'System.Data.DataView'.
the code is
Dim plmExcelCon As New System.Data.OleDb.OleDbConnection
Dim cmdLoadExcel As System.Data.OleDb.OleDbDataAdapter
Dim PrmPathExcelFile As String
[Code]......
this is more a theoretical question i asked myself.I remembered that BinarySearch of an ordered List(Collection in general) is faster than finding Rows with Datatable.Rows.Find or DataTable.FindByPK with a primary key value.Hence i fill a Datatable from Database in a shared constructor and immediately after that a List(of Int32) that contains all primary keys from that table. Later i will check with BinarySearch if the List contains primary-key values. But because the datatable contains only the PK-Column anyway, i asked myself if there is a way to avoid the huge overhead of filling a Datatable and after that adding all Rows to a List. Is it possible to fill a generic List(or other collection-type) instead of a Datatable/Dataset directly from a Dataadapter?Maybe i'm off the track and there is another way to avoid the Extra-Loop that i'm missing.
The code of filling the DataTable in a strong typed Dataset and the List:
Private Shared w205CorrectSWUpgrades As New List(Of Int32)
Shared Sub New()
[code].....
I have an InvalidCastException Error in my program. The program is that i try to insert an employee record into a database table after getting the details from a form. I've used Money data type is SQL Server for salary and SqlTypes.SqlDecimal data type in employee template class. i've used a stored procedure to pass the values and i add the basic value by passing a parameter by the method
Dim prm8 As SqlParameter = com.Parameters.Add("@basic", SqlDbType.Money)
prm8.Direction = ParameterDirection.Input
prm8.Value = emp.Bsc
I've used the money datatype itself even in the stored procedure variable.I get the following error.
failed to convert parameter value from sql decimal to decimal
Even if i use
prm8.Value = Convert.ToDecimal(emp.Bsc)
I get an error Unable to cast object of type 'System.Data.SqlTypes.SqlDecimal' to type 'System.IConvertible'.
I am getting this error when I am tring to load string type to data table)
Using connection As New SqlConnection("connectionstring;")
connection.Open()
Using Command As New SqlCommand("SELECT ClientId,forename,surname from t_clientdetails
[code].....
I get the below error Unable to cast object of type 'System.String' to type 'System.Data.DataTable'.This is the code I'm using
Dim str As String = String.Empty
If (Session("Brief") IsNot Nothing) Then
Dim dt As DataTable = Session("Brief")
If (dt.Rows.Count > 0) Then
[code]....
I have a bit of trouble right here, I am trying to get the data from the site and input them in the listview. Well, when my main app start to load through on debug, then it start to display a warning. The warning is: Unable to cast object of type 'System.String' to type 'System.IFormatProvider'.
[Code]...
I have tried everything I can to get beyond this error which shows below as <<<<< error here. It is trying to fill a dataset from a data adapter. If I change the SELECT statement to just SELECT * FROM xTable I get the correct number of records in each table. But anytime I try with a more complex statement I get the error message shown below which indicates System.Data.Common.DbDataAdapter.Fill(DataSet dataSet. I've completely erased all data and entered a new set of test data so I know there is no problem with relationships. Each table has primary key which is foreign key in other table. IS there something wrong with the Imports section: Imports System
[Code]...
I've spent a substantial amount of time trying to figure this out, but I keep getting the same error
A first chance exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll
A first chance exception of type 'System.NullReferenceException' occurred in project1.exe
This happens when I try to use the DataReader.my code is
Public Function Identification() As List(Of Integer)
Dim returnIndex As New List(Of Integer)
Dim dbCount As String = "SELECT Bookingid FROM bookdetail WHERE Date =" & getCurrentTimeString() & " 12:00:00 a.m."
Dim count As Integer = 0
[code]....
i am trying to copy data from a standard Dataset to a Type Dataset (XSD) of same table structure. i want to use Automapper to do that one. So how can i do that using automapper?
View 1 Repliesi need to clear this error
A first chance exception of type 'System.Data.OleDb.OleDbException' occurred in System.Data.dll
I am just trying to get the system to open a database and I get this error:
A first chance exception of type 'System.Data.SqlClient.SqlException' occurred in System.Data.dll
here's the entire code of the main form
=======================================
Imports System
Imports System.Data
Imports System.Data.SqlClient
[code]....
the error is generated at the open method note* this same code works fine in another computer, the main difference is that this one has a 64 bit OS.
I am using VS 2008, Office 2007, and Win7 Home Premium on my system.I have a simple application which should be a breeze to build. All I am attempting to do is pull data from an Access database with four small tables into a data grid on a windows project. Should be simple, set up the data connection, choose a datagrid from the table in the data source view, drag it onto the page and done, right?I can't get it to work. It will all work fine until I attempt to run or debug the project. The data will not show up. The data grid does, but I get this error: A first chance exception of type 'System.InvalidOperationException' occurred in System.Data.dll
As I said, the project seems to build fine, but it will not pull the data. After the initial build I get the message that Windows will show this page in Compatibility View. Is it something with Win7 Home Premium, or a setting somewhere?
Do While rdr2.Read()
Dim var1 As String = rdr2.Item("Week").ToString
Dim var2 As String = rdr2.Item("L1").ToString
Dim var3 As String = rdr2.Item("L2").ToString
It generates the following error: A first chance exception of type 'System.Data.SqlServerCe.SqlCeException' occurred in System.Data.SqlServerCe.dll
Interestingly, if I use a numeric value for the variable it for LSArraytemp, it writes to the database no problem at all.
VB 2008, DataGridView,DataGridView1_CellLeave(sender, New System.EventArgs)
"Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.DataGridViewCellEventArgs'."
What is the Correct String for "New System.EventsArgs"
Anybody there is to help me out.
I am using a background worker and am attempting to use the following code. However I keep getting this error on i "Unable to cast object of type 'ObjectCollection' to type 'System.Array'."
Private Sub btnVerify_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnVerify.Click
myArray = listProxies.Items()
BackgroundWorker1.RunWorkerAsync()
End Sub
[code]....
A first chance exception of type 'System.InvalidOperationException' occurred in System.Windows.Forms.dll It displays in my Immediate Window when i run my program, I'm using a text reader to read a number of XML files using background worker...most the time it stops so something is wrong but sometimes it works fine.
View 2 Repliesi am getting the xml using readxml method. And then display the data in datagrid. But number type columns comes as string type in the dataset. So when datagrid displays , sortingdatagrid columns is not correct. For example it sorts like this:
Salary
1180
12133
[code]......
I have a dataset and want to know the data type of a specific column. The GetType returns datacolumn not string or integer etc.iggy!
View 2 RepliesI need to read data from an Excel sheet as part of a data conversion. Certain columns contain mostly numeric data but may contain some alphanumeric data somewhere in the excel sheet. The problem is, my conversion sees the alphanumeric values as null (or blank. Using the .ToString() method returns ""). To connect to Excel, I'm creating an oledb connection, creating an OleDbDataAdapter, then filling a DataSet with the adapter.
Here's the VB code for connecting:
private _oleadpt As OleDbDataAdapter
private _oleconnection As New OleDbConnection
Dim olecomm As OleDbCommand
'_database comes from a settings file and is the full path to an excel document
Dim connstring As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & _database & ";
Extended Properties=""Excel 8.0;HDR=YES;"""
[Code] .....
I think the data adapter is determining the datatype for the columns based on the first however-many rows it looks at. It decides the columns with numbers are numeric which is the start of my problem. Changing the formatting of the column in Excel doesn't seem to affect the datatypes in my data set. Is there a way to tell the dataadapter or dataset what type of data to use for a column? Or should I try to cast the data in my SQL statement?
Ever since I started using VB.Net I have been using the Generic List collection List(Of <Type>). Arrays, I haven't used so much. I used them a lot more when I wrote C code years ago.
1.) Are arrays considered a type of collection like Lists, Dictionary, Queue etc are? Or are they in their own category.
2.) Can I iterate over an array with a For Each loop like I can with other collections or do I stick with the normal For loop for arrays?
3.) There are certain methods that return arrays. Can I set a list object to hold this return value instead of an array?
I am trying to insert a small message of 150 characters into the "AdvertisingInfo" database into the "QuickPost" column. Right now there is only one row that will have various columns updated by several forms.I just started to teach myself VB10 and it has taken me 6 hours to get this far. I'm tired of trying today and am going to bed, but I need help trying to figure this out. I keep getting the error: Value of type 'Integer' cannot be converted to 'System.Data.DataSet'.[code]
View 3 RepliesWhen setting a DataSet row column to Nothing, like row.Date = Nothing, why does it initialize it to the data type minvalue? In this case a date, that gets set to 0000-01-01. The column is set to allow null etc., and if I don't set the row to anything at all, it will leave the column empty. So why does Nothing act this way?
In C# I would've set it to DbNull, I guess, but I'm a tad green on VB.NET - as you might be able to tell. :)
I'm getting an error after sending a list to a web service.This is the code that is calling the web service:
Dim sProgramInterest As New List(Of Integer)
crmService.InsertProspectGetId(sProgramInterest.ToList)
But I'm getting this error.
[code].....
My project worked a first and now its giving me a problem.The error
Quote:
Unable to cast object of type 'System.Windows.Forms.MouseEventArgs' to type 'System.ComponentModel.RunWorkerCompletedEventArgs'.
[URL]The issue is as soon as I change the value of the text boxes it gives me an error and forces me to close the project.
The error is:Unable to cast object of type 'System.EventArgs' to type 'System.Windows.Forms.KeyPressEventArgs'.
However I'm supposed to clear the number of gallons used and the total charged when a change is made to the contents of the 2 text boxes on the form.
