Help needed converting ftBytes to string

[LucieLastic]

hi

I'm reading a memo field from Sybase and would like to store it in a varchar field in SQLServer. I know that the field contains a hexadecimal number but they're stored as binary on the Sybase end. When I read this field in the field.datatype is ftBytes. How can I convert this hexadecimal number (stored as bytes) in to a string?

I have this so far (found on the web) but it is just returned #0 for each converted byte:

:
    else if Field.DataType in [ftBytes, ftVarBytes] then
    begin
      result := VariantToString(field.value);
    end
    else
:

function TFormLoader.VariantToString(const vArray: variant): string;
  var Cnt: integer;

    function VarToString(const V: variant): string;
      var Vt: integer;
    begin
      Vt := VarType(V);
      case Vt of
        {02}varSmallint,
        {03}varInteger : result := Inttostr(integer(V));
        {04}varSingle,
        {05}varDouble,
        {06}varCurrency : result := Floattostr(Double(V));
        {07}varDate : ;//result := usgFormatDateTime(TDateTime(V));
        {08}varOleStr : result := WideString(V);
        {0B}varBoolean : ;//result := TF[Boolean(V)];
        {0C}varVariant : result := VariantToString(Variant(V));
        {11}varByte : result := char(byte(V));       //<---- This is the one which gets used
        {100}varString : result := String(V);
        {2000}varArray : result := VariantToString(Variant(V));
      end; {case }
    end;

begin
  result := '';
  if (vartype(vArray) and VarArray)=0
    then result := VarToString(vArray)
    else  for Cnt := VarArrayLowBound(vArray, 1) to
             VarArrayHighBound(vArray, 1) do
                result := result+VarToString(vArray[Cnt]);
end;

Grateful for any help on this one!

Cheers, guys
Lou

 

[majlumbo]

Try something like this.

Haven't tested it though...

function TForm1.ByteToHex(InByte:Byte): String;
const 
   Digits:array[0..15] of char='0123456789ABCDEF';
begin
   Result := Digits[InByte shr 4]+digits[InByte and $0F];
end;

function TForm1.HexToString(H: String): String;
var 
   I : Integer;
begin
  Result := '';
  for I := 1 to length (H) div 2 do
     Result:= Result + Char(StrToInt('$'+Copy(H,(I-1)*2+1,2)));
end;



var
   MyHexString:  String;
begin
   MyHexString := HexToString(ByToHex(<DBfieldName>.AsByte));
   ...
end;

 

[LucieLastic]

hi majlumbo

I'm at home now but I will try it first thing in the morning. Many thanks for your help.

Lou

 

[towerbase]

I would have thought that using the Format function with a format specifier of %x would be simpler.

For example

MyHexString := Format( '%x', [ <DBfieldName>.AsByte) ] );

The format specifier can include a width so that if you wanted an 8 character hexadecimal number padded with leading zeros you would code

MyHexString := Format( '%.8x', [ <DBfieldName>.AsByte) ] );

Andrew