Field.DataSize returns a wrong length
lazarus / 16-Databases

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tintinux · 2010-10-27 12:35

Hi

On Lazarus 0.28.2.

Why does the function Field.DataSize returns the actual length +1 for
a ftString or other ?

This is obvious from the code of dsparams.inc.

But Why +1 ??  Isn't it a bug ?

Bye
Tintinux

Code: [Select]Function TParam.GetDataSize: Integer;
begin
  Result:=0;
  case DataType of
    ftUnknown  :
DatabaseErrorFmt(SUnknownParamFieldType,[Name],DataSet);
    ftBoolean  : Result:=SizeOf(WordBool);
    ftInteger,
    ftAutoInc  : Result:=SizeOf(Integer);
    ftSmallint : Result:=SizeOf(SmallInt);
    ftWord     : Result:=SizeOf(Word);
    ftTime,
    ftDate     : Result:=SizeOf(Integer);
    ftDateTime,
    ftCurrency,
    ftFloat    : Result:=SizeOf(Double);
    ftString,
    ftFixedChar,
    ftMemo,
    ftADT      : Result:=Length(AsString)+1;
    ftBytes,
    ftVarBytes : if VarIsArray(FValue) then
                   Result:=VarArrayHighBound(FValue,1)+1
                 else
                   Result:=0;
    ftBlob,
    ftGraphic..ftTypedBinary,
    ftOraClob,
    ftOraBlob  : Result:=Length(AsString);
    ftArray,
    ftDataSet,
    ftReference,
    ftCursor   : Result:=0;
  else
    DatabaseErrorFmt(SBadParamFieldType,[Name],DataSet);
  end;

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clauslack · 2010-10-27 19:45

I think that

Field.DataSize is the size of the buffer.

Field.Size has the correct length.



Regards

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Lacak2 · 2010-10-28 04:49

Exactly see also
http://docwiki.embarcadero.com/VCL/XE/en/DB.TField.DataSize