Author: Jonas Bilinkevicius 

How to add a password to several Paradox tables in one step

Answer:
1   
2   procedure BDEProtectTable(ATable: TTable; const APassword: string);
3   var
4     CurPrp: CURProps;
5     hDB: hDBIdb;
6     TableDesc: CRTblDesc;
7     DoEncrypt: boolean;
8     bExcl, bOpen: boolean;
9   begin
10    Check(DBIGetCursorProps(ATable.Handle, CurPrp));
11    DoEncrypt := (APassword > '');
12    with ATable do
13    begin
14      bOpen := Active;
15      bExcl := Exclusive;
16      if Active and not Exclusive then
17        Close;
18      if not Exclusive then
19        Exclusive := True;
20      if not Active then
21        Open;
22      {supply nulls (=default) for every optional parameter:}
23      FillChar(TableDesc, SizeOf(CRTblDesc), 0);
24      {supply indispensable parameters:}
25      AnsiToNative(DBLocale, TableName, TableDesc.szTblName, DBIMAXTBLNAMELEN - 1);
26      TableDesc.szTblType := CurPrp.szTableType;
27      {supply parameters for our action here:}
28      AnsiToNative(DBLocale, APassword, TableDesc.szPassword, 255);
29      TableDesc.bProtected := DoEncrypt; {supply False to decrypt}
30      hDB := DBHandle;
31      Close;
32      {do the restructure:}
33      try
34        Check(DBIDoRestructure(hDB, 1, @TableDesc, nil, nil, nil, False));
35      finally
36        Exclusive := bExcl;
37        Active := bOpen;
38      end;
39    end;
40  end;