procedure TFormInput.BitBtn1Click(Sender: TObject);
var berat, C : double;
    B  : string;
begin
  if length(EPnjg.Text)<>0 then
    pnjg:=StrToFloat(trim(EPnjg.Text)) else pnjg := 0;;
  if length(ELbr1.Text)<>0 then
    lbr1:=StrToFloat(trim(ELbr1.Text)) else lbr1 := 0;
  if length(ELbr2.Text)<>0 then
    lbr2:=StrToFloat(trim(ELbr2.Text)) else lbr2 := 0;
  ...

  ...
  if RadioButton1.Checked then begin
    luas1:=((lbr1+lbr2)/2)pnjg;
    if (luas1<=L2) then begin
  // jangan gunakan perintah execSQL, tetapi gunakan perintah open
  // karena kita ingin mengambil datanya bukan mengerjakan query berupa
  // perintah
        with QuSem do begin
            Prepare;
            Params[0].AsString:=DBECodMat.Text;
            Open;
        end;
        C:=QuSem['beratt'];
        berat:=(luas1/L2) C;
        Str(berat:12:6,B);
        EInpBrt.Text:=B;
        QuSem.Close;
    end
  else exit;
end;
if RadioButton2.Checked then
begin
    luas:=pnjglbr1;
    if (luas<=L2) then
    begin
  // disini juga begitu, jangan gunakan execSQL, tetapi open untuk
  // mengambil datanya
        with QuSem do
        begin
            Prepare;
            Params[0].AsString:=DBECodMat.Text;
            Open;
            C:=QuSem['beratt'];
            berat:=(luas/L2) C;
            Str(berat:12:6,B);
            EInpBrt.Text:=B;
            Close;
        end;
    end
    else exit
end;

procedure TFormInput.ESubOrdExit(Sender: TObject);
begin
  ...
  if length(ESubOrd.Text)=0 then
  begin
   ShowMessage('Masukkan nomer SubOrder');
   ESubOrd.SetFocus;
   Exit;
  end;
  ...
end;

procedure TFormMRP.BitBtnSimpanClick(Sender: TObject);
begin
  with QuInpMrp do begin
   ...   
   Prepare;
   execsql;
  end;
  clear;
end;

INSERT INTO tbMRP(Order, Material, Utk, Spesifikasi, Jumlah, Berat)
VALUES(:ord, :matr, :ut, :spek, :jml, :brt)

INSERT INTO tbMRP([Order], Material, Utk, Spesifikasi, Jumlah,Berat)
VALUES(:ord, :matr, :ut, :spek, :jml, :brt)

procedure TFormMRP.BitBtnSimpanClick(Sender: TObject);
begin
  ....
  end;
  clear;
  QuMRP.Close;
  QuMRP.Open;
  ....
end;

procedure TFormCodAct.EKodeAktifitasKeyPress(Sender: TObject;
  var Key: Char);
begin
  ...
    SQl.Clear;
    if length(EKodeAktifitas.Text)<>0 then
     QuCodAct.SQL.Add('SELECT  FROM tbCodAct WHERE SubOrder='
     +quotedstr(EKodeAktifitas.Text)+'');
    Prepare;
  ...
end;

    if length(EKodeAktifitas.Text)<>0 then
     QuCodAct.SQL.Add('SELECT   FROM tbCodAct WHERE SubOrder='
     +quotedstr(EKodeAktifitas.Text)+'') else
     QuCodAct.SQL.Add('SELECT  FROM tbCodAct');

procedure TFormSteel.EKodeMaterialPlatKeyPress(Sender: TObject;
  var Key: Char);
begin
  ...
    if length(EKodeMaterialPlat.Text)<>0 then
     QuMatr.SQL.Add('SELECT   FROM tbMate WHERE kode_matrl='
     +QuotedStr(EKodeMaterialPlat.Text)+'');
    Prepare;
  ...
end;

    if length(EKodeMaterialPlat.Text) <> 0 then
     QuMatr.SQL.Add('SELECT  FROM tbMate WHERE kode_matrl='
     +QuotedStr(EKodeMaterialPlat.Text)+'') else
     QuMatr.SQL.Add('SELECT   FROM tbMate');