How do I fix "Public member 'Length' on type 'DBNull' not found" Excel Import Error in .NET?

Posted on 2008-10-21
Last Modified: 2011-10-19
How do I fix "Public member 'Length' on type 'DBNull' not found" Excel Import Error in .NET?
I have attached the file I am attempting to import and the code behind.  The code works, I have successfully used it on another file, but why not this one?

Any help is greatly appreciated.

What am I missing?
Partial Class crc_importcertificates
    Inherits System.Web.UI.Page
    Protected Sub btImport_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btImport.Click
        If FileUpload.HasFile Then
            Dim strFileName As String = ""
            Dim oleDbCommand As New Data.OleDb.OleDbCommand
            Dim oleDbReader As Data.OleDb.OleDbDataReader
            Dim sqlCommand As New Data.SqlClient.SqlCommand("crc_ImportCertificates", New Data.SqlClient.SqlConnection(ConfigurationManager.ConnectionStrings("cnDWS").ConnectionString))
            sqlCommand.CommandType = Data.CommandType.StoredProcedure
            'Save File to random filename
            strFileName = ConfigurationManager.AppSettings("FileUploadPath").ToString & CStr(Rnd()) & ".xls"
            If Not System.IO.File.Exists(strFileName) Then
            End If
            oleDbCommand.Connection = New Data.OleDb.OleDbConnection(Replace(ConfigurationManager.AppSettings("cnACT").ToString, "FILENAME", strFileName))
            oleDbCommand.CommandText = "SELECT * FROM [ExportCertificateData$];"
            oleDbReader = oleDbCommand.ExecuteReader
            sqlCommand.Parameters.Add("@first_name", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@last_name", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@address", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@city", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@state", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@zip", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@username", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@password", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@certificate_level", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@mathematics_level", Data.SqlDbType.TinyInt)
            sqlCommand.Parameters.Add("@mathematics_tested", Data.SqlDbType.DateTime)
            sqlCommand.Parameters.Add("@reading_level", Data.SqlDbType.TinyInt)
            sqlCommand.Parameters.Add("@reading_tested", Data.SqlDbType.DateTime)
            sqlCommand.Parameters.Add("@locating_level", Data.SqlDbType.TinyInt)
            sqlCommand.Parameters.Add("@locating_tested", Data.SqlDbType.DateTime)
            sqlCommand.Parameters.Add("@certificate_issued", Data.SqlDbType.DateTime)
            sqlCommand.Parameters.Add("@expiration", Data.SqlDbType.DateTime)
            sqlCommand.Parameters.Add("@testing_location", Data.SqlDbType.VarChar)
            sqlCommand.Parameters.Add("@act_certificate_number", Data.SqlDbType.VarChar)
            'loop through records and update crc_certificates based on results
            While oleDbReader.Read()
                sqlCommand.Parameters("@first_name").Value = IIf(oleDbReader("First Name").Length = 0, System.DBNull.Value, oleDbReader("First Name"))
                sqlCommand.Parameters("@last_name").Value = IIf(oleDbReader("Last Name").Length = 0, System.DBNull.Value, oleDbReader("Last Name"))
                sqlCommand.Parameters("@address").Value = IIf(oleDbReader("Primary Address1").Length = 0, System.DBNull.Value, oleDbReader("Primary Address1"))
                sqlCommand.Parameters("@address").Value &= IIf(oleDbReader("Primary Address2").Length = 0, System.DBNull.Value, oleDbReader("Primary Address2"))
                sqlCommand.Parameters("@address").Value &= IIf(oleDbReader("Primary Address3").Length = 0, System.DBNull.Value, oleDbReader("Primary Address3"))
                sqlCommand.Parameters("@city").Value = IIf(oleDbReader("Primary City").Length = 0, System.DBNull.Value, oleDbReader("Primary City"))
                sqlCommand.Parameters("@state").Value = IIf(oleDbReader("Primary State").Length = 0, System.DBNull.Value, oleDbReader("Primary State"))
                sqlCommand.Parameters("@zip").Value = IIf(oleDbReader("Primary PostalCode/ZipCode").Length = 0, System.DBNull.Value, oleDbReader("Primary PostalCode/ZipCode"))
                sqlCommand.Parameters("@username").Value = oleDbReader("MyWorkKeys UserName")
                sqlCommand.Parameters("@password").Value = oleDbReader("Password")
                sqlCommand.Parameters("@certificate_level").Value = oleDbReader("Certificate Level")
                sqlCommand.Parameters("@mathematics_level").Value = oleDbReader("Applied Mathematics Score")
                sqlCommand.Parameters("@mathematics_tested").Value = oleDbReader("Applied Mathematics Test Date")
                sqlCommand.Parameters("@reading_level").Value = oleDbReader("Reading for Information Score")
                sqlCommand.Parameters("@reading_tested").Value = oleDbReader("Reading for Information Test Date")
                sqlCommand.Parameters("@locating_level").Value = oleDbReader("Locating Information Score")
                sqlCommand.Parameters("@locating_tested").Value = oleDbReader("Locating Information Test Date")
                sqlCommand.Parameters("@certificate_issued").Value = oleDbReader("Certificate Issue Date")
                sqlCommand.Parameters("@expiration").Value = oleDbReader("Certificate Expiration Date")
                sqlCommand.Parameters("@testing_location").Value = oleDbReader("Last Known Testing Location")
                sqlCommand.Parameters("@act_certificate_number").Value = oleDbReader("Certificate Identifier")
            End While
            'clean up
            lblStatus.Visible = True
        End If
    End Sub
    Protected Sub btReturn_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btReturn.Click
        Response.Redirect("default.aspx", True)
    End Sub
End Class

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Question by:devnewbee
1 Comment
LVL 18

Accepted Solution

UnifiedIS earned 500 total points
ID: 22769483
You can also usually just bypass the null checks with empty strings
sqlCommand.Parameters("@address") = string.empty & oleDbReader("Primary Address1")

Another way would be to reverse your iiif logic
if isdbnull(oledbreader(fieldname)) then dbnull.value else oledbreader(fieldname)


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