Paradox-Tabellen per Programm ändern?

[MrSpock]

Hallo FBrust,

Informationen wie z.B. Vorgabewerte werden in einer internen Struktur CRTblDesc gespeichert. Diese kann man mit dem Aufruf der function DbiDoRestructure ändern.

Hier ein Beispiel aus der OH zur BDE 4.0:

Delphi-Quellcode:

procedure fDbiDoRestructure(Tbl: TTable; Field: TField; MinVal, MaxVal, DefVal: pLongint; Required: Bool);
var
  hDb: hDbiDb;
  TblDesc: CRTblDesc;
  VChk: pVChkDesc;
  Dir: String;
  NumVChks: Word;
  OpType: CROpType;

begin
  NumVChks := 0;
  SetLength(Dir, dbiMaxNameLen + 1);
  Check(DbiGetDirectory(Tbl.DBHandle, False, PChar(Dir)));
  SetLength(Dir, StrLen(PChar(Dir)));
  VChk := AllocMem(sizeof(VChkDesc));
  try
    FillChar(TblDesc, sizeof(CRTblDesc), #0);

    VChk.iFldNum := Field.Index + 1;
    Tbl.DisableControls;
    Tbl.Close;
    Check(DbiOpenDatabase(nil, nil, dbiReadWrite, dbiOpenExcl, nil, 0, nil, nil, hDb));
    Check(DbiSetDirectory(hDb, PChar(Dir)));
    with VChk^ do
    begin
      bRequired := Required;
      if MinVal <> nil then
      begin
        Inc(NumVChks);
        bHasMinVal := True;
        move(MinVal^, aMinVal, sizeof(MinVal^));
      end
      else
        bHasMinVal := False;
      if MaxVal <> nil then

      begin
        Inc(NumVChks);
        bHasMaxVal := True;
        move(MaxVal^, aMaxVal, sizeof(MaxVal^));
      end
      else
        bHasMaxVal := False;
      if DefVal <> nil then
      begin
        Inc(NumVChks);
        bHasDefVal := True;
        move(DefVal^, aDefVal, sizeof(DefVal^));
      end
      else
        bHasDefVal := False;

    end;
    TblDesc.iValChkCount := NumVChks;
    TblDesc.pVChkDesc := VChk;
    OpType := crADD;
    TblDesc.pecrValChkOp := @OpType;

    StrPCopy(TblDesc.szTblName, Tbl.TableName);
    StrCopy(TblDesc.szTblType, szParadox);
    Check(DbiDoRestructure(hDb, 1, @TblDesc, nil, nil, nil, False));
  finally
    Check(DbiCloseDatabase(hDb));
    FreeMem(VChk, sizeof(VChkDesc));
    Tbl.EnableControls;
    Tbl.Open;
  end;
end;

[edit=MrSpock]Beispiel hinzugefügt[/edit]