recursive function

[Andreas Schubert]

Hello newsgroup,

i need a recursive funtion to fill a treeviewstructu re.
my table looks like this:

category_id, Category, Parent

where Parent points to category_id when it is a subentry.
Now I use this to read all data of the table:

Dim strSQL As String
strSQL = "SELECT * FROM categories"
Dim myConnection As SqlConnection
myConnection = New SqlConnection(m _connStr)
Dim mySqlDataAdapte r As SqlDataAdapter = New SqlDataAdapter( strSQL,
myConnection)
Dim myDataSet As DataSet = New DataSet
Dim i As Integer
mySqlDataAdapte r.Fill(myDataSe t, "Categories ")

Now I need a function to enumerate through all the data in the dataset and
add the nodes to the treeview and calling itself if subentries have to be
entered.
How do I do such a thing?
I am an absolute newbie with .NET

Thanks for your help

Andreas

[david]

Re: recursive function

On 2005-09-17, Andreas Schubert <anwendungsprog rammierer.Remov eSpam@web.de> wrote:[color=blue]
> Hello newsgroup,
>
> i need a recursive funtion to fill a treeviewstructu re.
> my table looks like this:
>
> category_id, Category, Parent
>
> where Parent points to category_id when it is a subentry.
> Now I use this to read all data of the table:
>
> Dim strSQL As String
> strSQL = "SELECT * FROM categories"
> Dim myConnection As SqlConnection
> myConnection = New SqlConnection(m _connStr)
> Dim mySqlDataAdapte r As SqlDataAdapter = New SqlDataAdapter( strSQL,
> myConnection)
> Dim myDataSet As DataSet = New DataSet
> Dim i As Integer
> mySqlDataAdapte r.Fill(myDataSe t, "Categories ")
>
> Now I need a function to enumerate through all the data in the dataset and
> add the nodes to the treeview and calling itself if subentries have to be
> entered.
> How do I do such a thing?
> I am an absolute newbie with .NET[/color]

There's more efficient ways of doing this, but this untested example
should more or less work...

Private Sub FillLevel(ByVal nodes As TreeNodeCollect ion, _
ByVal dt As DataTable, ByVal parentID As Integer)

Dim rows() As DataRow = _
dt.Select("Pare nt = " & parentID.ToStri ng(), "")
For Each row As DataRow In rows
Dim node As TreeNode = nodes.Add(row(" Category").ToSt ring())
FillLevel(node. Nodes, dt, CInt(row("categ ory_id")))
Next
End Sub

' And kick it off with

FillLevel(MyTre eView.Nodes, myDataSet.Table s(0), TOP_LEVEL_ID)

where top_level_id is how you identify your top-level entries.

[Andreas Schubert]

Re: recursive function

thanks david, will give it a try

"david" <david@woofix.l ocal.dom> schrieb im Newsbeitrag
news:slrndiojlr .ep3.david@loca lhost.localdoma in...[color=blue]
> On 2005-09-17, Andreas Schubert
> <anwendungsprog rammierer.Remov eSpam@web.de> wrote:[color=green]
>> Hello newsgroup,
>>
>> i need a recursive funtion to fill a treeviewstructu re.
>> my table looks like this:
>>
>> category_id, Category, Parent
>>
>> where Parent points to category_id when it is a subentry.
>> Now I use this to read all data of the table:
>>
>> Dim strSQL As String
>> strSQL = "SELECT * FROM categories"
>> Dim myConnection As SqlConnection
>> myConnection = New SqlConnection(m _connStr)
>> Dim mySqlDataAdapte r As SqlDataAdapter = New SqlDataAdapter( strSQL,
>> myConnection)
>> Dim myDataSet As DataSet = New DataSet
>> Dim i As Integer
>> mySqlDataAdapte r.Fill(myDataSe t, "Categories ")
>>
>> Now I need a function to enumerate through all the data in the dataset
>> and
>> add the nodes to the treeview and calling itself if subentries have to be
>> entered.
>> How do I do such a thing?
>> I am an absolute newbie with .NET[/color]
>
> There's more efficient ways of doing this, but this untested example
> should more or less work...
>
> Private Sub FillLevel(ByVal nodes As TreeNodeCollect ion, _
> ByVal dt As DataTable, ByVal parentID As Integer)
>
> Dim rows() As DataRow = _
> dt.Select("Pare nt = " & parentID.ToStri ng(), "")
> For Each row As DataRow In rows
> Dim node As TreeNode = nodes.Add(row(" Category").ToSt ring())
> FillLevel(node. Nodes, dt, CInt(row("categ ory_id")))
> Next
> End Sub
>
> ' And kick it off with
>
> FillLevel(MyTre eView.Nodes, myDataSet.Table s(0), TOP_LEVEL_ID)
>
> where top_level_id is how you identify your top-level entries.
>
>[/color]

[Andreas Schubert]

Re: recursive function

thank you very much, works like a charm.

Andy

"david" <david@woofix.l ocal.dom> schrieb im Newsbeitrag
news:slrndiojlr .ep3.david@loca lhost.localdoma in...[color=blue]
> On 2005-09-17, Andreas Schubert
> <anwendungsprog rammierer.Remov eSpam@web.de> wrote:[color=green]
>> Hello newsgroup,
>>
>> i need a recursive funtion to fill a treeviewstructu re.
>> my table looks like this:
>>
>> category_id, Category, Parent
>>
>> where Parent points to category_id when it is a subentry.
>> Now I use this to read all data of the table:
>>
>> Dim strSQL As String
>> strSQL = "SELECT * FROM categories"
>> Dim myConnection As SqlConnection
>> myConnection = New SqlConnection(m _connStr)
>> Dim mySqlDataAdapte r As SqlDataAdapter = New SqlDataAdapter( strSQL,
>> myConnection)
>> Dim myDataSet As DataSet = New DataSet
>> Dim i As Integer
>> mySqlDataAdapte r.Fill(myDataSe t, "Categories ")
>>
>> Now I need a function to enumerate through all the data in the dataset
>> and
>> add the nodes to the treeview and calling itself if subentries have to be
>> entered.
>> How do I do such a thing?
>> I am an absolute newbie with .NET[/color]
>
> There's more efficient ways of doing this, but this untested example
> should more or less work...
>
> Private Sub FillLevel(ByVal nodes As TreeNodeCollect ion, _
> ByVal dt As DataTable, ByVal parentID As Integer)
>
> Dim rows() As DataRow = _
> dt.Select("Pare nt = " & parentID.ToStri ng(), "")
> For Each row As DataRow In rows
> Dim node As TreeNode = nodes.Add(row(" Category").ToSt ring())
> FillLevel(node. Nodes, dt, CInt(row("categ ory_id")))
> Next
> End Sub
>
> ' And kick it off with
>
> FillLevel(MyTre eView.Nodes, myDataSet.Table s(0), TOP_LEVEL_ID)
>
> where top_level_id is how you identify your top-level entries.
>
>[/color]