這樣一個函數要怎麼寫啊

Question

下面的是要執行的內容
   var str:string;
begin
    str:='select * from customertype where tcode='''+trim(cxDBButtonEdit4.text)+'''';
    with dm.qscan02 do
    begin
      close;
      sql.clear;
      sql.add(str);
      open;
    end;
    if dm.qscan02.RecordCount<=0 then
      begin
      showmessage('Type is not exist');      cxDBButtonEdit4.text:='';
      end;
end;
要求該函數可以傳入cxDBButtonEdit4的值和表名稱customertype 和字段名稱tcode
返回的結果為boolen值黨RecordCount<=0時為false >0 時為true

Answer 1

function www(str:string):boolean ;
Var
  Data:TAdoQuery;
begin
  Data:=TadoQuery.Create(nil);
  try
    Try
    Data.Connection:=  //在这赋一个可用的TAdoConnection
      with Data do
      begin
        sql.Text:='select count(*) as count from customertype where tcode='+#39+trim(str)+#39;
        prepared:=true;
        open;
        if fieldbyname('count').AsInteger<1 then
          Result:=false
        else
          Result:=true;
      end;
    Finally
      Data.Free;
    End;
  except
    Data.Free;
    showmessage('出错了!');
  end;
end;