object reference not set

[TG]

hi!

I have a combobox where the user can type the sql server name. Then a
connect button that, when the user click, I want it to populate
another combobox with all the databases from the server in the
previous combobox.

Unfortunately, i am getting the error object reference is not set....!

Here is where i am getting the error:

For Each objDB As Database In Me.SMOServer.Da tabases


I am new to VB ...I'm using vb2008 connecting to sql server 2005.


Your help is appreciated.

Thanks!

Tammy






Here is my complete code:

Imports Microsoft.SqlSe rver.Management .Smo
Imports Microsoft.SqlSe rver.Management .Common
Public Class Form1

'Public Class frmSQLConnectio n


Private m_objServer As Server
Public Property SMOServer() As Server
Get
Return m_objServer
End Get
Private Set(ByVal value As Server)
m_objServer = value
End Set
End Property



Private m_objDatabase As Database
Public Property SMODatabase() As Database
Get
Return m_objDatabase
End Get
Private Set(ByVal value As Database)
m_objDatabase = value
End Set
End Property

Private Sub Form1_Load(ByVa l sender As System.Object, ByVal e As
System.EventArg s) Handles MyBase.Load

Dim objServers As DataTable
Dim strServer As String

'---- retrieve a list of SQL Server instances on the network
objServers = SmoApplication. EnumAvailableSq lServers(False)

For Each objRow As DataRow In objServers.Rows

strServer = CStr(objRow("Se rver"))
If Not TypeOf objRow("Instanc e") Is DBNull AndAlso
CStr(objRow("In stance")).Lengt h 0 Then

strServer += "\" & CStr(objRow("In stance"))

End If

Me.comboServers .Items.Add(strS erver)

Next

Me.ComboDatabas e.Enabled = False

End Sub



Private Sub button1_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button1.Click

Dim objConn As ServerConnectio n

If Me.comboServers .Text.Trim.Leng th() = 0 Then


objConn = New ServerConnectio n()

If Me.comboServers .Text.Trim.Leng th() 0 Then

objConn.ServerI nstance = Me.comboServers .Text.Trim()

End If


Me.SMOServer = New Server(objConn)

End If


'---- Note: the connection will open when we call our first
method on the Server object


Me.ComboDatabas e.Items.Clear()


For Each objDB As Database In Me.SMOServer.Da tabases


Me.ComboDatabas e.Items.Add(obj DB.Name)


Next

Me.ComboDatabas e.Enabled = True

Me.ComboDatabas e.SelectedIndex = 0




End Sub


Private Sub button2_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button2.Click

SMODatabase = Me.SMOServer.Da tabases(Me.Comb oDatabase.Text)

Me.DialogResult = Windows.Forms.D ialogResult.OK

Me.Close()

End Sub


Private Sub button3_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button3.Click

Me.DialogResult = Windows.Forms.D ialogResult.Can cel

Me.Close()

End Sub

End Class

[=?ISO-8859-1?Q?G=F6ran_Andersson?=]

Re: object reference not set

TG wrote:

hi!
>
I have a combobox where the user can type the sql server name. Then a
connect button that, when the user click, I want it to populate
another combobox with all the databases from the server in the
previous combobox.
>
Unfortunately, i am getting the error object reference is not set....!
>
Here is where i am getting the error:
>
For Each objDB As Database In Me.SMOServer.Da tabases
>
>
I am new to VB ...I'm using vb2008 connecting to sql server 2005.
>
>
Your help is appreciated.
>
Thanks!
>
Tammy
>

8<

>
Private Sub button1_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button1.Click
>
Dim objConn As ServerConnectio n

You only assign anything to the SMOServer property if the content of the
combobox is empty:

If Me.comboServers .Text.Trim.Leng th() = 0 Then
>
>
objConn = New ServerConnectio n()
>
If Me.comboServers .Text.Trim.Leng th() 0 Then

This line can never be reached:

objConn.ServerI nstance = Me.comboServers .Text.Trim()
>
End If
>
>
Me.SMOServer = New Server(objConn)
>
End If
>

--
Göran Andersson
_____

http://www.guffa.com

[=?Utf-8?B?RmFtaWx5IFRyZWUgTWlrZQ==?=]

RE: object reference not set

If I'm reading the code below correctly, SMOServer is only set if the
combobox text length is zero. That doesn't sound likely or correct. Inside
that if block you test the length greater than zero. I think your if block
needs to be reworked.

Private Sub button1_Click(B yVal sender As System.Object, ByVal e
As System.EventArg s) Handles Button1.Click
>
Dim objConn As ServerConnectio n
>
If Me.comboServers .Text.Trim.Leng th() = 0 Then
>
>
objConn = New ServerConnectio n()
>
If Me.comboServers .Text.Trim.Leng th() 0 Then
>
objConn.ServerI nstance = Me.comboServers .Text.Trim()
>
End If
>
>
Me.SMOServer = New Server(objConn)
>
End If
>
>
'---- Note: the connection will open when we call our first
method on the Server object
>
>
Me.ComboDatabas e.Items.Clear()
>
>
For Each objDB As Database In Me.SMOServer.Da tabases
>
>
Me.ComboDatabas e.Items.Add(obj DB.Name)
>
>
Next
>
Me.ComboDatabas e.Enabled = True
>
Me.ComboDatabas e.SelectedIndex = 0
>
>
>
>
End Sub
>
>
>

[TG]

Re: object reference not set

How should I re-write it?

Like I said i am new to VB and I found something similar to this which
I was trying to modify to get what I need.

Thanks a lot for your help guys!

Tammy

[TG]

Re: object reference not set

I got it!



Private Sub button1_Click(B yVal sender As System.Object, ByVal e As
System.EventArg s) Handles Button1.Click

Dim objConn As ServerConnectio n

'If Me.comboServers .Text.Trim.Leng th() = 0 Then


objConn = New ServerConnectio n()

If Me.comboServers .Text.Trim.Leng th() 0 Then

objConn.ServerI nstance = Me.comboServers .Text.Trim()

End If


Me.SMOServer = New Server(objConn)

'End If


'---- Note: the connection will open when we call our first
method on the Server object


Me.ComboDatabas e.Items.Clear()


For Each objDB As Database In Me.SMOServer.Da tabases


Me.ComboDatabas e.Items.Add(obj DB.Name)


Next

Me.ComboDatabas e.Enabled = True

Me.ComboDatabas e.SelectedIndex = 0




I commented out this line and now I get the results I was looking
for!!!!!

Thanks a lot for pointing me in the right direction!!!! :-)


Tammy