what is possible wrong with my codes : The Official Microsoft ASP.NET Forums

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what is possible wrong with my codes

Feb 24, 2012 06:09 PM|LINK

i see this error any time i try to up load photo to my database.

"Object reference not set to an instance of an object" what is possible wrong with my codes?

###############################################

Imports System.Data.SqlClient
Imports System.Data

Partial Class _Default
    Inherits System.Web.UI.Page

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Try 'Checking the file in fileupload
            If FileUpload1.HasFile Then


                Dim imageSize As Byte()
                imageSize = New Byte(FileUpload1.PostedFile.ContentLength - 1) {}




                Dim postfile As HttpPostedFile = FileUpload1.PostedFile()


                postfile.InputStream.Read(imageSize, 0, CInt(FileUpload1.PostedFile.ContentLength))


                ' Create SQL Connection
                Dim campusplus As New SqlConnection()
                campusplus.ConnectionString = ConfigurationManager.ConnectionStrings("campusplus").ConnectionString


                ' Create SQL Command
                'Checking file type
                If postfile.ContentType.ToLower() = "image/gif" Then


                    Dim cmd As New SqlCommand()
                    cmd.CommandText = "INSERT INTO upload(fileid,ImageName,Image) VALUES (@fileid,@ImageName,@Image)"
                    cmd.CommandType = CommandType.Text
                    cmd.Connection = campusplus
                    Dim ImageName As New SqlParameter("@ImageName", SqlDbType.VarChar, 50)
                    ImageName.Value = TextBox1.Text.ToString
                    cmd.Parameters.Add(ImageName)


                    Dim imagelenth As New SqlParameter("@Image", SqlDbType.Image, imageSize.Length)
                    imagelenth.Value = imageSize
                    cmd.Parameters.Add(imagelenth)
                    campusplus.Open()
                    Dim result As Integer = cmd.ExecuteNonQuery()
                    campusplus.Close()
                Else
                    Label1.Text = "Its not a gif image"
                End If
            Else
                Label1.Text = "please select the file to uplaod"
            End If
        Catch ex As Exception
            Response.Write(ex.Message)
        End Try


    End Sub

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

End Class

###########################################################

this how my db looks

Edited by Nana Adu on Feb 25, 2012 04:13 PM
Edited by Nana Adu on Feb 25, 2012 04:18 PM

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Re: what is possible wrong with my codes

Feb 24, 2012 06:12 PM|LINK

That error means one of your fields is null and the database is expecting something to be input, most likely an integer. Do a check for null variable and if the value is null or empty, present value as dbnull and database should take it.

Mark as answer posts that helped you.

Marked as answer by dalong zhang - msft on Mar 02, 2012 08:23 AM

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skcookie

Member

534 Points

138 Posts

Re: what is possible wrong with my codes

Feb 24, 2012 06:30 PM|LINK

you can also use sql profiler to exam the exact sql statement that is being execute on the sql side if you are using a EF or some other mapper. This might help you to quickly narrow down what field is being left empty.

Also if you are using in page sql that you have not accidentally miss spelled one of the names of the sql parameters This would cause one of the parameters to not being populated even though you are providing an appropriate value.

Thanks,

Patrick P.
Microsoft Certified Professional

Remember to mark as answer where appropriate!