Dim get_rmf_2 = From rmf In t_rmf _ Where rmf!NIVP = nivp_rap
When i run it i get an error :
Operator '=' is not defined for type 'DBNull' and string "test".
I suspect this is because the column "NIVP" in the datatable contains null values, I've tried yhe same thing without null values and it works.So how can i make this work ? ; the column "NIVP" really has a row "test" , and a normal SQL query works fine.
I have this little problem :Operator '=' is not defined for type 'DBNull' and type 'Boolean'. This the code: For i As Int32 = Me.DataGridViewSearch.Rows.Count - 1 To 0 Step i - 1 If DataGridViewSearch.Rows(i).Cells(6).Selected = True Then Try What I am trying to do is to loop threw a datagrid and find the checkboces that are checked.
The intent of the code is to open an xls file -minimize it , search for keywords . there are columns like test case name ,priority(simple ,medium and high) with associated keywords.If keywords are found, it shld save the test case name - Priority in a text box. When i run this code i am getting err in
I'm having a contextmenu in a datagridview. I need to disable a menuitem if there is no value in the currentrow.cells(..).value.I tried several thing, but no luck: If dgv.currentrows.cells(1).value= "" then... 'disabe menuitem. I'm getting the error: Operator '=' is not defined for type 'DBNull' and type 'Integer'.
Public Pixels(0 To 95, 0 To 127) As Variant Red = Pixels(X, Y) And &HFF i get this code from VB6, and when i transfer to VB05 i got problem said " Operator 'And' is not defined for type 'Color' and type 'Integer'. " i sent to VS2005
Public Pixels(0 To 95, 0 To 127) As Object Dim red As Object Red = Pixels(X, Y) And &HFF
I've got a problem in one of my SQL queries, the type GUID can't be used with the operator & (obviously from the title). Here's the few lines of code which I'm using:
Dim ClientsAssetID As Guid = New Guid(ClientsAssetIDTextBox.Text) Dim Client1 As Guid = New Guid(Client1TextBox.Text) Dim Client2 As Guid = New Guid(Client2TextBox.Text)
ClientsAsset, Client1, Client2 and Client3 are all of type GUID, but are entered into the textboxes as strings, are converted to guid and then should all go smoothly into the query, but it's having a problem with linking everything together. The error I'm getting is "Operator '&' is not defined for types 'String' and 'System.Guid'.How do I fix this? I've tried a few different things, such as using Ctype in the query, but they have also circled back to this error.
I am working on a site that I would like to pass information from one page to another. I'm new to asp.net but not other languages, I'm just trying to learn some stuff. For some reason I keep getting the above error. The code I am using looks real similar to the code in the Murach book I am looking at
I'm trying to add a new record to my database but i keep getting the message - "conversion from type DBnull to type string is not valid". I think its something to do with the Employee ID when VB attempts to save it to the database my code is below
Imports System.Data.OleDb Public Class Add Private Sub DisplayRow()
Error 1Server Error in '/ Application. -------------------------------------------------------------------------------- Conversion from type 'DBNull' to type 'String' is not valid. Description: 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. Exception Details: System.InvalidCastException: Conversion from type 'DBNull' to type 'String' is not valid. Source Error: Line 64: Line 65:
I was tried to get quantity from db make use of the selection in list box. I got answered with listbox1. If i selected the item in listbox1 the quantity would appear in textbox1. But in this same code will not work for listbox2 with textbox4.. Here i given the code...
$Con.open() $Dim cd as new oledb.oledbcommand("Select Quantity from tlist where tool_name"& "'"listbox2.selecteditem & "'" & "", con)
Here i got the error as "Conversion from type DBNull to type string is not valid"
I've been getting this error when pulling data from a recordset. It is coming from a null entry and as a newbie to VB2008 I'm not sure how to get around this.
here is my code lblShipping.Text = reader("CARRIERCODE")
the error:Conversion from type 'DBNull' to type 'String' is not valid. Basically what i'm attempting to accomplish is to see if there is anything in that field. If so put it into the text box if not leave it blank.
I am importing an Excel spreadsheet, turning it into a dataset and inserting the results into SQL Server (only 100 rows).
I am having an issue with one of the date columns in Excel, which can have a value or not. The "F" column is the one that may be blank and this is the error I get: Conversion from type 'DBNull' to type 'String' is not valid.
How can I add a check to the Dim F As Date = CDate(row(5)) to handle a null?
VB ' The use of letters instead of ' more descriptive variables is ' strictly for this sample peice
i try to put picture in mysql with vb.net, first i convert with this function : [code] i try to use that function for storing picture to mysql database : INSERT INTO myImage (image) VALUES ('" & convertImage(PictureBox1.image) & "');and then i have this error : Operator '&' is not defined for types 'String' and '1-dimensional array of Byte'i create a table (myImage) with image field (LongBlob)
At run time my application gives an error of "Conversion from type "DBNull" to type "String" is not valid. In my form only one field - Add_info is an optional field which might be filled or not by the user. Before, I had an error when an apostrophe was used so i updated the code as highlighted below. This in return removed the apostrophe error but generated an error whenever there is an empty additional field. [code]
I am pulling records from an access database onto my form and have a "Next" button to get to the next record, but every time it gets to the 5th record, the error msg, "Conversion from type DBNull to type String is not valid." because one of the text boxes (fields) from the database is empty.