第一个表

procedure Tfrm_BroadcastCenter.FormCreate(Sender: TObject);
var
  errmsg,sql: string;
  i: integer;
begin
  inherited;
  //创建数据链表
  FpDataList := TList.Create;
  stringList1:=TStringList.Create;
  stringList2:=TStringList.Create;
  stringList3:=TStringList.Create;
  stringList1.Clear;
  //cxComboBox4.Clear;
  //显示查询项中省的内容
  sql:='select * from PROVINCE';
  if ExecADOQueryMsg('MainCon', sql, adoquery, errmsg) then
  begin
    i := 1;
    while not ADOQuery.Eof do
    begin
      cxComboBox4.Properties.Items.Add(ADOQuery.fieldbyname('NAME').AsString);
      stringList1.Add(ADOQuery.fieldbyname('PROVINCEID').AsString);
      //cxComboBox4.Properties.Items.in
      ADOQuery.Next;
    end;
  end
end; 

 

第二个表

procedure Tfrm_BroadcastCenter.cxComboBox4PropertiesChange(
  Sender: TObject);
var
  errmsg,sql: string;
  i: integer;
begin
  inherited;
  stringList2.Clear;
  cxComboBox5.Properties.Items.Clear;
  cxComboBox5.Text:='';
  cxComboBox6.Text:='';
  //显示查询项中市的内容
  sql:='select * from CITY where FATHER=''' + StringList1.Strings[cxComboBox4.ItemIndex] + '''';
  if ExecADOQueryMsg('MainCon', sql, adoquery, errmsg) then
  begin
    i := 1;
    while not ADOQuery.Eof do
    begin
      cxComboBox5.Properties.Items.Add(ADOQuery.fieldbyname('NAME').AsString);
      stringList2.Add(ADOQuery.fieldbyname('CITYID').AsString);
      ADOQuery.Next;
    end;
  end
end;

 

第三个表

procedure Tfrm_BroadcastCenter.cxComboBox5PropertiesChange(
  Sender: TObject);
var
  errmsg,sql: string;
  i: integer;
begin
  inherited;
  stringList3.Clear;
  cxComboBox6.Properties.Items.Clear;
  cxComboBox6.Text:='';
  //显示查询项中县的内容
  sql:='select * from AREA where FATHER=''' + StringList2.Strings[cxComboBox5.ItemIndex] + '''';
  if ExecADOQueryMsg('MainCon', sql, adoquery, errmsg) then
  begin
    i := 1;
    while not ADOQuery.Eof do
    begin
      cxComboBox6.Properties.Items.Add(ADOQuery.fieldbyname('NAME').AsString);
      stringList3.Add(ADOQuery.fieldbyname('AREAID').AsString);
      ADOQuery.Next;
    end;
  end
end;
end.

 

本文来源：http://blog.csdn.net/linjie_here/archive/2007/08/21/1752910.aspx