Construct a Treeview based on the data in the database

The data structure of the database is as follows:
Scompany_no varchar (10) unchecked
Scompany_name varchar (50) unchecked
Sshortname varchar (30) checked
Sparent_no varchar (10) checked
Stree varchar (30) checked
Itreelevel int checked
The specific data is as follows:

000001

Head Office

Abbreviation

Null

001

1

000002

Company 2

Abbreviation

000001

001001

2

000003	Company 3	Abbreviation	000001	001002	2
000004	Company 4	Abbreviation	000001	001003	2
000005	Company 4	Abbreviation	000001	001004	2
000006	Company 4 subordinates	Abbreviation	000005	001004001	3
000007	Company 4 subordinate 2	Abbreviation	000005	001004002	3

Construct the C # Of the Treeview # Code As follows: (implemented using recursive methods) Initialize the Department tree # Region Initialize the Department tree
// Bytes --------------------------------------------------------------------------------------------------------
/**//// <Summary>
///Orm initializes the Department tree
/// </Summary>
/// <Param name = "totreeview">Specify a target Treeview</Param>
Public   Static   Void Companytree_init (Treeview totreeview)
{
Totreeview. nodes. Clear ();
Int Ilevel =   1 ; // Tmpcorp. itreelevel;
Ortcompany Corp =   New Ortcompany ();
Ordatareader < Ortcompany > Reader = Corp. dataaccessor. executereader (commandtype. Text, " Select * From tcompany where sStatus = '1' " , Corp, Null );

Treenode tmpnode =   New Treenode ();
Foreach (Ortcompany u In Reader) // Loop each row of data
{
If (( Int ) U. itreelevel = Ilevel)
{
Treenode rootnode =   New Treenode ();
Rootnode. Text = U. scompany_no.tostring (). Trim () + U. sshortname. tostring (). Trim ();
Rootnode. Value = U. scompany_no.tostring (). Trim ();
Rootnode. tooltip = U. scompany_name;
Totreeview. nodes. Add (rootnode );
Rootnode. Expanded =   True ;
}
Else
{
Tmpnode =   Null ;
For ( Int I =   0 ; I < Totreeview. nodes. Count; I ++ )
{
Treenode ttnode =   New Treenode ();
Ttnode = Findnode (totreeview. nodes [I], U. sparent_no.tostring (). Trim ());
If (Ttnode ! =   Null ) Tmpnode = Ttnode;
}
If (Tmpnode ! =   Null )
{
Treenode subnode =   New Treenode ();
Subnode. Text = U. scompany_no.tostring (). Trim () + U. sshortname. tostring (). Trim ();
Subnode. Value = U. scompany_no.tostring (). Trim ();
Subnode. tooltip = U. scompany_name;
Tmpnode. childnodes. Add (subnode );
Subnode. Expanded =   True ;
}
}
}
Reader. Close ();
}
/**/ ///   <Summary>
/// Recursive search for parent nodes
///   </Summary>
///   <Param name = "tnparent"> Specify a root node and traverse it </Param>
///   <Param name = "strvalue"> Value of the node to be searched </Param>
Public   Static Treenode findnode (treenode tnparent, String Strvalue)
{
If (Tnparent =   Null ) Return   Null ;
If (Tnparent. Value = Strvalue) Return Tnparent;
Treenode tnret =   Null ;
Foreach (Treenode TN In Tnparent. childnodes)
{
Tnret=Findnode (TN, strvalue );
If(Tnret! = Null)Break;
}
Return Tnret;
}
# Endregion

The ORM is used to obtain data. You can use it without it.