关于treeview和oda连接SQL server(100分)

如何实现在treeview中实现与数据库的连接问题，使数据库的目录结构能在其中显示？[green][/green]

var
mytreenode1,mytreenode2,mytreenode3:ttreenode;
begin

maindm.adoqycpy.open;
employeefrm.treeview1.items.clear;
with employeefrm.treeview1.items do
begin
MyTreeNode1:=add(nil,'公司名称');

maindm.adoqycpy.first;
while not maindm.adoqycpy.Eof do
begin
with employeefrm.treeview1.Items do
begin
mytreenode2:= addchild(mytreenode1,trim(maindm.adoqycpy.fieldbyname('cname').asstring));

//查找单位下的部门
with maindm.adoqydept do
begin
close;
sql.clear;
sql.add('select * from b_department where compid=:compid');
Parameters.ParamByName('compid').value :=trim(maindm.adoqycpy.fieldbyname('compid').asstring);
open;
end;
maindm.adoqydept.first;
while not maindm.adoqydept.eof do
begin
mytreenode3:=addchild(mytreenode2,trim(maindm.adoqydept.fieldbyname('deptname').asstring));
mytreenode3.StateIndex:=maindm.adoqydept.Fieldbyname('deptid').asinteger;
maindm.adoqydept.Next;
end;

end;
maindm.adoqycpy.next;
end;
end;
end;