FireDAC中官方SQL语句增insert，查Select，删delete，改update语句写法(20)

procedure TfrmGettingStarted.btnInsertClick(Sender: TObject);
var
  iID: Integer;
begin
  if not FDconnection1.Connected then    Exit;
  // Insert a record   增
  FDconnection1.ExecSQL('insert into Categories(CategoryName, Description, Picture) ' +
                 'values(:N, :D, :P)', ['New category', 'New description', $0334]);
  FDQuery1.Refresh;

  // Get a scalar value from DB, 查
  iID := FDconnection1.ExecSQLScalar('select MAX(CategoryID) from Categories');
  ca := 'Last CategoryID = ' + IntToStr(iID);
end;

procedure TfrmGettingStarted.btnUpdateClick(Sender: TObject);
begin
  if not FDconnection1.Connected then     Exit;
  // Update records  改
  FDconnection1.ExecSQL('update Products set UnitPrice = UnitPrice * :P1 + :P2 ' +
                 'where ProductID < 3', [Random(5), Random(3)]);
  FDQuery2.Refresh;
end;

procedure TfrmGettingStarted.btnDeleteClick(Sender: TObject);
begin
  if not FDconnection1.Connected then     Exit;

  // Delete a record  删
  FDconnection1.ExecSQL('delete from Categories where CategoryName like :N', ['New category']);
  FDQuery1.Refresh;
end;