Databases :: Catching NULL Values Error "Cannot Cast DBNull.Value To Type 'System.Double'. Please Use A Nullable Type"
Apr 21, 2010
I am LINQ querrying against a datatable. However, I am unsuccessfull with catching null values. Here is my code that is giving me the following error.
[Code]....
I am checking to see if minperc is null. However to check that it still is trying to convert the value to double. Cant figure out a way around it. Here is the error: Cannot cast DBNull.Value to type 'System.Double'. Please use a nullable type.
Basically, what I did is that: I have a table in SQL database and some of data fields allow null. I built Objectdatasource through dataset. When I built update page using dataset. It generate the following error before showing the update page correctly. It seems I have issue to retrieve the null value from the database through using objectdatasource through dataset. Any suggestions?An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code
I am trying to write a table output from SQL database to a gridview/ Data List through an Object Data Source. I am a new starter and your help will be useful.
public List<Staff> GetStaff() cmd.CommandType = SqlConnection con = new SqlConnection(connectionstring);SqlCommand cmd = new [code]...
I am making a website to store invoices so i can mail them to clients. So i got a table for clients, invoices and one with invoice products/services. When an invoice has no products/services added to them and it returns null i get the error "the null value cannot be assigned to a member with type System.Decimal which is a non-nullable value type."
I just started with linq. Before i always used mysql. Mostly i just had to call data from 1 table so forgive me if my linq query isn't really correct.
Dim invoices = From i In db.invoices _ Group Join p In db.products On i.id Equals p.invoiceId Into invoiceProducts = Group _ Select New With {i.client.naam, i.titel, (From iP In invoiceProducts Select iP.prijs).Sum}
i show the client's name, the title of the invoice and the total amount the clients will need to pay for products and services.
When i click on the page that represents a controller the following error was displayed:-
"The null value cannot be assigned to a member with type System.Int32 which is a non-nullable value type"
On this link of code
var articleapproval = articletyperepository.FindAllArticlesRequireMyApproval().ToList(); while the FindAllArticlesRequireMyApproval execute the following LINQ statement :- var articleapproval= articletyperepository.FindAllArticlesRequireMyApproval().ToList();
where this methods calls the following LINQ statement:-
I want to do paging the API Membership without using the datacontrols, but I get this error "Unable to cast object of type '<TakeIterator>d__3a`1[System.Char]' to type 'System.Collections.IList'." when I do this,
Above is my code. The error I'm get is, Unable to cast object of type 'System.DateTime' to type 'System.String'.
The column "To" and column "Subject" are strings and column "Receive" is DateTime. I can't made any changes in the database, so I need to write some code to handle casting a string to datetime or if statement as a work around.
Protected Sub FormView1_ItemCreated(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.FormViewCommandEventArgs) Handles FormView1.ItemCreated Causes Unable to cast object of type 'System.EventArgs' to type 'System.Web.UI.WebControls.FormViewCommandEventArgs'.
The program (asp.net/vb) works fine with FormView1_ItemCommand and FormView1_ItemInserted events but strangely objects to FormView1_ItemCreated. Is it only a VC# event?
[Code].... System.InvalidCastException was unhandled by user code Message=Unable to cast object of type 'System.Guid' to type 'System.String'. Source=System.Data.Linq System.Data.Linq.SqlClient.SqlProvider.System.Data.Linq.Provider.IProvider.Execut
I've got a subweb as application. It's called ADMIN. It works fine when running locally but when deploying in the development web server, i got the error: Unable to cast object of type 'System.Web.HttpApplication' to type 'Microsoft.Practices.CompositeWeb.WebClientApplication'
I've got a App_global.asax.dll and App_global.asax.complied on the subweb folder Admin.
I have a gridview which I'm trying to get the display of phonenumbers listed in a certain display format; (xxx) xxx-xxxx.If I have the code such as this, it displays the unformatted phone number and (000) 000-0000 for the null items.
I have a web site that is using windows authentication. 'Enable anonymous access' is unchecked. It works when I call it through Visual Studio but when I put the site on the server I get the following error:
Unable to cast object of type 'System.Security.Principal.GenericPrincipal' to type 'System.Web.Security.RolePrincipal'.
I am trying to pass a collection of Dropdown controls as a parameter to a method which takes a collection of type Control as input. While executing I get the following error:
"Unable to cast object of type 'd__a31[System.Web.UI.WebControls.DropDownList]' to type 'System.Collections.Generic.IEnumerable1[System.Web.UI.Control]'."
This error is occuring randomly, and I can't seem to pinpoint what is causing it. For the most part, the code works fine. I'm confused why it works sometimes, but then suddently craps out on me, lol.It happens in the code when I call upon the asp.net membership provider. It only seems to happen when i use Membership.GetUser() to grab the logged in user's information.
what is wrong with this syntax datatable temp = (DataTable)du.Rows[0]["NAME"] I get the error message Unable to cast object of type 'System.String' to type 'System.Data.DataTable'.
The ChecBox will be selected according to the user need: 1, 2, 3 or plus... When the page is fired, I wanted to get in the code behind the box which are checked so I can build a query consequently. So in the code behin, i wrote this:
Dim MyCheckBox As CheckBox Even if I try Dim MyCheckBox As New CheckBox I was getting the same error below. For Each MyCheckBox In Form.Controls For j As Integer = 1 To 12 If TypeOf MyCheckBox Is CheckBox Then MyCheckBox.ID = MonthName(j) If CType(MyCheckBox, CheckBox).Checked = True Then TargetedFieldName = MyCheckBox.ID 'Build a query against tables MyCheckBoxCollection += TargetedFieldName & ", " End If End If Next Next
I'm getting right after For Each statement this error: Unable to cast object of type 'System.Web.UI.LiteralControl' to type 'System.Web.UI.WebControls.CheckBox'.
I got the following error when i tried to insert a new record after the run my project, so what does this error indicates?
"{"Cannot insert explicit value for identity column in table 'Articles' when IDENTITY_INSERT is set to OFF."} System.Exception {System.Data.SqlClient.SqlException}
