G
Guest
I'm trying to use the Insert.aspx Quickstart and I'm getting a NULL pointer
exception. Any help?
<code>
<script language="VB" runat="server">
Dim myConnection As SqlConnection
Sub Page_Load(Src As Object, e As EventArgs)
' Create a connection to the SQL Server
myConnection = New SqlConnection("Data Source=SERVER;" _
& "Initial Catalog=database;User Id=user;Password=password;")
' Check whether this page is a postback. If it is not
' a postback, call a custom BindGrid function.
If Not IsPostBack Then
BindGrid()
End If
End Sub
' Implement an AddAsset_Click function. This function does some data
' validation on the input form and builds a parameterized command
containing
' all the fields of the input form. Then it executes this command to the
' database and tests (using the try command) whether the data was added.
' Finally, it rebinds the DataGrid to show the new data.
Sub AddAsset_Click(Sender As Object, e As EventArgs)
Dim myCommand As SqlCommand
Dim insertCmd As String
' Check the Cube and Computer Serial input values and make sure they
are not
' empty. If they are empty, show a message to the user and rebind the
DataGrid.
If (cube.Value = "" Or computer_serial.Value = "")
Message.InnerHtml = "ERROR: You MUST enter a Cube and Computer S/N "
Message.Style("color") = "red"
BindGrid()
Exit Sub
End If
' Build a SQL INSERT statement string for all the input-form
' field values.
insertCmd = "insert into myTable values (@cube, @monitor_type,
@monitor_serial, @acd, " _
& "@ext, @computer_type, @computer_serial, @hostname,
@second_comp_serial, @second_hostname);"
' Initialize the SqlCommand with the new SQL string.
myCommand = New SqlCommand(insertCmd, myConnection)
' Create new parameters for the SqlCommand object and
' initialize them to the input-form field values.
'Cube data
myCommand.Parameters.Add(New SqlParameter("@cube", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@cube").Value = cube.Value
'Monitor Type data
myCommand.Parameters.Add(New SqlParameter("@monitor_type", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@monitor_type").Value = monitor_type.Value
'Monitor Serial data
myCommand.Parameters.Add(New SqlParameter("@monitor_serial", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@monitor_serial").Value = monitor_serial.Value
'ACD (position ID) data
myCommand.Parameters.Add(New SqlParameter("@acd", _
SqlDbType.VarChar, 4))
myCommand.Parameters("@acd").Value = acd.Value
'Extension data
myCommand.Parameters.Add(New SqlParameter("@ext", _
SqlDbType.VarChar, 12))
myCommand.Parameters("@ext").Value = ext.Value
'Computer Type data
myCommand.Parameters.Add(New SqlParameter("@computer_type", _
SqlDbType.VarChar, 20))
myCommand.Parameters("@computer_type").Value = computer_type.Value
'Computer Serial data
myCommand.Parameters.Add(New SqlParameter("@computer_serial", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@computer_serial").Value = computer_serial.Value
'Hostname data
myCommand.Parameters.Add(New SqlParameter("@hostname", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@hostname").Value = hostname.Value
'2nd Computer Serial data
myCommand.Parameters.Add(New SqlParameter("@second_comp_serial", _
SqlDbType.VarChar,50))
myCommand.Parameters("@second_comp_serial").Value =
second_comp_serial.Value
'2nd Hostname data
myCommand.Parameters.Add(New SqlParameter("@second_hostname", _
SqlDbType.VarChar,50))
myCommand.Parameters("@second_hostname").Value = second_hostname.Value
myCommand.Connection.Open() THIS IS WHERE THE EXCEPTION IS
' Test whether the new row can be added and display the
' appropriate message box to the user.
Try
myCommand.ExecuteNonQuery()
Message.InnerHtml = "<b>Record Added</b><br>" & insertCmd
Catch ex As SqlException
If ex.Number = 2627 Then
Message.InnerHtml = "ERROR: A record already exists with " _
& "the same Computer Serial Number"
Else
Message.InnerHtml = "ERROR: Could not add record, please " _
& "ensure the fields are correctly filled out"
Message.Style("color") = "red"
End If
End Try
myCommand.Connection.Close()
BindGrid()
End Sub
' BindGrid connects to the database and implements a SQL
' SELECT query to get all the data in the table
' of the database.
Sub BindGrid()
Dim myConnection As SqlConnection
Dim myCommand As SqlDataAdapter
' Create a connection to the "database" SQL Server
myConnection = New SqlConnection("data source=SERVER;" _
& "user id=user;password=password;initial catalog=Database")
' Connect to the SQL database using a SQL SELECT query to get all
' the data from the table.
myCommand = New SqlDataAdapter("SELECT * FROM myTable", _
myConnection)
' Create and fill a new DataSet.
Dim ds As DataSet = New DataSet()
myCommand.Fill(ds)
' Bind the DataGrid control to the DataSet.
dgInserted.DataSource = ds
dgInserted.DataBind()
End Sub
</script>
</code>
I'm getting a NULL pointer exception on:
myCommand.Connection.Open()
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an
object.]
ASP.conInsert_aspx.AddAsset_Click(Object Sender, EventArgs e) in
C:\inventory\Insert.aspx:96
System.Web.UI.HtmlControls.HtmlInputButton.OnServerClick(EventArgs e)
System.Web.UI.HtmlControls.HtmlInputButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler
sourceControl, String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
System.Web.UI.Page.ProcessRequestMain()
Everything looks good to me. Most of the code is from the MSDN Quickstart
and I've just tweaked it to allow for my database.
AM I MISSING SOMETHING?
exception. Any help?
<code>
<script language="VB" runat="server">
Dim myConnection As SqlConnection
Sub Page_Load(Src As Object, e As EventArgs)
' Create a connection to the SQL Server
myConnection = New SqlConnection("Data Source=SERVER;" _
& "Initial Catalog=database;User Id=user;Password=password;")
' Check whether this page is a postback. If it is not
' a postback, call a custom BindGrid function.
If Not IsPostBack Then
BindGrid()
End If
End Sub
' Implement an AddAsset_Click function. This function does some data
' validation on the input form and builds a parameterized command
containing
' all the fields of the input form. Then it executes this command to the
' database and tests (using the try command) whether the data was added.
' Finally, it rebinds the DataGrid to show the new data.
Sub AddAsset_Click(Sender As Object, e As EventArgs)
Dim myCommand As SqlCommand
Dim insertCmd As String
' Check the Cube and Computer Serial input values and make sure they
are not
' empty. If they are empty, show a message to the user and rebind the
DataGrid.
If (cube.Value = "" Or computer_serial.Value = "")
Message.InnerHtml = "ERROR: You MUST enter a Cube and Computer S/N "
Message.Style("color") = "red"
BindGrid()
Exit Sub
End If
' Build a SQL INSERT statement string for all the input-form
' field values.
insertCmd = "insert into myTable values (@cube, @monitor_type,
@monitor_serial, @acd, " _
& "@ext, @computer_type, @computer_serial, @hostname,
@second_comp_serial, @second_hostname);"
' Initialize the SqlCommand with the new SQL string.
myCommand = New SqlCommand(insertCmd, myConnection)
' Create new parameters for the SqlCommand object and
' initialize them to the input-form field values.
'Cube data
myCommand.Parameters.Add(New SqlParameter("@cube", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@cube").Value = cube.Value
'Monitor Type data
myCommand.Parameters.Add(New SqlParameter("@monitor_type", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@monitor_type").Value = monitor_type.Value
'Monitor Serial data
myCommand.Parameters.Add(New SqlParameter("@monitor_serial", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@monitor_serial").Value = monitor_serial.Value
'ACD (position ID) data
myCommand.Parameters.Add(New SqlParameter("@acd", _
SqlDbType.VarChar, 4))
myCommand.Parameters("@acd").Value = acd.Value
'Extension data
myCommand.Parameters.Add(New SqlParameter("@ext", _
SqlDbType.VarChar, 12))
myCommand.Parameters("@ext").Value = ext.Value
'Computer Type data
myCommand.Parameters.Add(New SqlParameter("@computer_type", _
SqlDbType.VarChar, 20))
myCommand.Parameters("@computer_type").Value = computer_type.Value
'Computer Serial data
myCommand.Parameters.Add(New SqlParameter("@computer_serial", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@computer_serial").Value = computer_serial.Value
'Hostname data
myCommand.Parameters.Add(New SqlParameter("@hostname", _
SqlDbType.VarChar, 50))
myCommand.Parameters("@hostname").Value = hostname.Value
'2nd Computer Serial data
myCommand.Parameters.Add(New SqlParameter("@second_comp_serial", _
SqlDbType.VarChar,50))
myCommand.Parameters("@second_comp_serial").Value =
second_comp_serial.Value
'2nd Hostname data
myCommand.Parameters.Add(New SqlParameter("@second_hostname", _
SqlDbType.VarChar,50))
myCommand.Parameters("@second_hostname").Value = second_hostname.Value
myCommand.Connection.Open() THIS IS WHERE THE EXCEPTION IS
' Test whether the new row can be added and display the
' appropriate message box to the user.
Try
myCommand.ExecuteNonQuery()
Message.InnerHtml = "<b>Record Added</b><br>" & insertCmd
Catch ex As SqlException
If ex.Number = 2627 Then
Message.InnerHtml = "ERROR: A record already exists with " _
& "the same Computer Serial Number"
Else
Message.InnerHtml = "ERROR: Could not add record, please " _
& "ensure the fields are correctly filled out"
Message.Style("color") = "red"
End If
End Try
myCommand.Connection.Close()
BindGrid()
End Sub
' BindGrid connects to the database and implements a SQL
' SELECT query to get all the data in the table
' of the database.
Sub BindGrid()
Dim myConnection As SqlConnection
Dim myCommand As SqlDataAdapter
' Create a connection to the "database" SQL Server
myConnection = New SqlConnection("data source=SERVER;" _
& "user id=user;password=password;initial catalog=Database")
' Connect to the SQL database using a SQL SELECT query to get all
' the data from the table.
myCommand = New SqlDataAdapter("SELECT * FROM myTable", _
myConnection)
' Create and fill a new DataSet.
Dim ds As DataSet = New DataSet()
myCommand.Fill(ds)
' Bind the DataGrid control to the DataSet.
dgInserted.DataSource = ds
dgInserted.DataBind()
End Sub
</script>
</code>
I'm getting a NULL pointer exception on:
myCommand.Connection.Open()
Stack Trace:
[NullReferenceException: Object reference not set to an instance of an
object.]
ASP.conInsert_aspx.AddAsset_Click(Object Sender, EventArgs e) in
C:\inventory\Insert.aspx:96
System.Web.UI.HtmlControls.HtmlInputButton.OnServerClick(EventArgs e)
System.Web.UI.HtmlControls.HtmlInputButton.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler
sourceControl, String eventArgument)
System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData)
System.Web.UI.Page.ProcessRequestMain()
Everything looks good to me. Most of the code is from the MSDN Quickstart
and I've just tweaked it to allow for my database.
AM I MISSING SOMETHING?