Update error , "Unable to cast object of type 'System.DBNull' to type 'System.String'" , using DataSet as a datasource
The following sample code is for testing dw.UpdateData using dataset as the
The data retrieval and display part under Form1_Load works fine.
However, inputting some values in a new row and calling dw.UpdateData causes
the following error:
"Unable to cast object of type 'System.DBNull' to type 'System.String'"
The error seems to occur when a datawindow column value has been changed
from null value.
Does anyone know how to fix the error ?
Thank you for your advice.
I use DW2.5 (build 8542), VS2005 pro, MS SQL Express.
...Cast from type 'DBNull' to type 'String' is not valid. Error
Can anyone help me with an error I am receiving "Cast from type 'DBNull' to type 'String' is not valid." I am creating an aspx page in VB.NET, please find attached code causing error.objCmd = New SqlCommand("USP_DisplayEmbarkDetails", objConn) objCmd.CommandType = CommandType.StoredProcedure objCmd.Parameters.Add("@BranchID", lblGetBranchID.Text) objConn.Open() objRdr = objCmd.ExecuteReader()
lblBranchName.Text=objRdr("BranchName") lblBranchID.Text=objRd...How do I get around this error "Unable to cast object of type 'System.DBNull' to type 'System.String' "
I am using Visual Developer 2008 Express Edition for the first time, and I keep getting the following error below. The site allows anyone to enter with a valid username and password, but even when I logoff the site I get the same error....like the memory or database is not getting refreshed. I would think that when I initially compile the site that anything left in memory would be flushed out. Can someone please help me to figure this out.
Thanks,Ramell P.S. The site is programmed using C#
Unable to cast object of type 'System.DBNull' to type 'System.String&...No Null Values but error Cast from type DBNull to type integer not valid
Here is my page load event. It runs this stored procedure to grab the adjustmentdisplayID from a table so that i can run a series of if else. THERE ARE NO NULL VALUES IN THIS TABLE. SO why would i be receiving this error? It points to this line:
dim display as integer = Cint(cmd1.Parameters("@AdjustmentDisplay").value)
Sub Page_Load(sender As Object, e As EventArgs)
if not Page.IsPostBack then
Dim Cmd1 as SqlCommand
Dim conn as SQLConnection
Conn = New SQLConnection(connstr)
Cmd1 = New SQLCommand("Getadjustmentdisplay",conn)
...Cast from type 'DBNull' to type 'String' is not valid.
How would I check to make sure my SQL db is not pulling a null value? I'm using the following code and I get the 'Cast from type 'DBNull' to type 'String' is not valid.' error.
If (dtrUserDetails("D_Address2") Is System.DBNull.Value) Then
_Address2 = ""
_Address2 = dtrUserDetails("D_Address2")
Any help would be much appreciated.
Change your line to
_Address2=dtrUserDetails("D_Address2") & ""
The empty string in the end will convert the filed to a string ...Cast from type 'DBNull' to type 'String' is not valid.
On the viewproduct page if any of the db fields referenced in the SP are empty you get the above error, the error originates in the productsDB.vb file as follows
myProductDetails.ModelNumber = CStr(parameterModelNumber.Value)
myProductDetails.ModelName = CStr(parameterModelName.Value)
myProductDetails.ProductImage = CStr(parameterProductImage.Value).Trim()
myProductDetails.UnitCost = CType(parameterUnitCost.Value, Decimal)
myProductDetails.Description = CStr(parameterDescription.Value).Trim()
OK I can make ...Cast from type 'DBNull' to type 'String' is not valid.
Ok, that is the error... "Cast from type 'DBNull' to type 'String' is not valid. "
I am filling a DataSet from the db and some fields are empty.
Reading from it and placing the info into a label.
Dim DSprod2 As New DataSet()
Dim MyCommand As OleDbDataAdapter
sql = "Select * from tblProducts Where fldNum = " & intfldNum
MyCommand = New OleDbDataAdapter(sql, conn)
lblProd.Text = DSprod2.Tables("...Cast from type 'DBNull' to type 'String' is not valid.
I have a page with several textboxes...it's a "change your account" page. One of the parameters is presented as a label instead since it is not changed ON THIS PAGE. It needs to be NULL when the account is created and entered later. But when the page loads, I get the above error. The account row is loaded from a business object LoadFromId().
How can I load the page even though this label data is NULL to start with? relevent code below.
<asp:Label ID="lblDDAccount" Runat="server"></asp:Label>------If currentUser.DDAccount = "" Then &...Cast from type 'DBNull' to type 'String' is not valid
I REALLY need some help, so here goes. The following function does work as long as the "mail" field in the database isn't NULL. As you can see I have tried a couple of ways to check for a NULL value but none of them seem to work. What's supposed to happen is the function checks to see whether or not a user has an email address in the database. If so, then the email address gets returned, if no email address then I need something back from the function so I can go about another way to get the info to the user.
Public Function GetReqByEmail(ByVal reqby As String) As String...Cast from type 'DBNull' to type 'String' is not valid
I have an old website and old database (SQL 2000). I add new column "ImageURL' to database, so all data (several thousand items) are "NULL" (actually is dbNull) under this column.
In searchResult.aspx page, inside the datagrid, I add a colummn call "Image"
<asp:datagrid id="dgSearchResult" runat="server"><Columns><asp:TemplateColumn HeaderText="Image" ItemStyle-Width="55px" ItemStyle-HorizontalAlign=Center> <ItemTemplate> <asp:Image ID=ThumbImage Wi...Cast from type 'DBNull' to type 'String' is not valid
Hi all,Sorry to be posting here on what is probably a common enough error but I am at my wits end with this one. Quite simply I call an Update stored procedure in my code, passing in a number of paramaters. However, when I try to run the code, the following exception is thrown:Cast from type 'DBNull' to type 'String' is not validI'm really not sure what the problem is here. I have tried hardcoding values for the string values with no success also, as well as using the IsNothing function, but no joy there eitherI would really appreciate someones help as I spent 2 hou...Error : Cast from type 'DBNull' to type 'Integer' is not valid
Hi all, I have beign figure the error for days but still cant figure out what's went wrong and no idea how to solve this error : Cast from type 'DBNull' to type 'Integer' is not valid. This is what i want to do :1.Display the number of item added into the shopping cart retrieved from the database. (workable)2.If there is qty eg. 2 in the shopping cart,it will display 2 items.(workable)3.But when i remove all the items in the shopping cart,this error : Cast from type 'DBNull' to type 'Integer' is not valid occured4. Anyone knows what code should...Cast from type 'DBNull' to type 'String' is not valid.
I have a problem when I try to read from a table "Ads" in my database and the value of the field is <NULL>. (I assume that I will come across a field that will be blank.) I’m not referencing any field in particular. I am learning .Net through I test project. When I delete a field in a record, for example "phone" I get following error:
Cast from type 'DBNull' to type 'String' is not valid.
Exception Details: System.InvalidCastException: Cast from type 'DBNull' to type 'String' is not valid.
I would like to not show the label at all if it's null. Fo...Cast from type 'DBNull' to type 'String' is not valid #2
Puzzled by this.
The error occurs on the field "Mobile" yet its format is exactly the same as the other fields.
In otherwords I can remove the line of code dealing with "Mobile" and it will function.
Can anyone explain?
The error is :
Cast from type 'DBNull' to type 'String' is not valid.