You may want to look at the TDBF component. I think the package is called
lazdbf or dbflaz.
Michael.
On Tue, 15 Jun 2010, Peter E Williams wrote:
Hi All,
I really need to know what is the Dbase3/4 unit for Lazarus/Free Pascal
and where is the sample project for manipulating them. I found it
somewhere on the lazarus website but don't know where. I hope that it is
okay for me to post some of my code which uses the XBase1 unit in Delphi
5 Enterprise which I am porting to my Hexxpawn8 game (which is cross
platform open source).
I use Dbase3/4+ files to store board patterns for my game which is sort
of a cross between the pawns in Chess and checkers, using AI logic
against the computer. (I chose Dbase format because it was the single
most common database file format at the time.)
What is the replacement unit for XBase1 for using Dbase3/4 files, and
the functions/procedures etc to replace these calls to XBase1 ?
How do I do the following:
// declaring a Dbase file -- TXBase (what is the equivalent in Lazarus?)
// how do I copy a blank.dfg file to hex8.bdf (Copyfile) ???
// I need to Goto to the Bottom of File (HexxData.GotoBOF;)
// I need to call a function GetFieldByName passing a string as the
field name and comparing it with a character
// I need to Goto the Next record (HexxData.GotoNext;)
// I need to Get the Record # (HexxData.RecNo;)
// and test the Dbase.EOF (not HexxData.EOF)
// and Append a Blank record (HexxData.AppendBlank;)
// save an integer to a Field (HexxData.UpdFieldStr('this_game',
inttostr(pattern.this_game)); )
// and Goto to the Record number (HexxData.GotoRecord(hexxdata_rec_no);)
See examples of my code below
Unit hexboard2.pas
// declaring a Dbase file -- TXBase
var
HexxData, TraceFile: TXBase;
procedure Thxboard.Open_db;
begin
if not fileExists('hex8.dbf') then
CopyFile('blank.dbf', 'hex8.dbf', false);
// how do I copy a blank.dfg file to hex8.bdf ???
HexxData := TXBase.create(nil);
// I assume that this is how to create a replacement for a Dbase file
HexxData.FileName := 'hex8.dbf';
HexxData.Active := true;
HexxData.GotoBOF;
// I need to Goto to the Bottom of File
end; { Open_db }
function Thxboard.pattern_is_db_current(pattern1: pattern_type):
boolean;
var
str_x, str_o: array[1..8] of string;
begin
pattern_is_db_current := false;
str(pattern1.x_piece[1], str_x[1]);
// ..
if (HexxData.GetFieldByName('x1_pos') = str_x[1]) and
// I need to call a function GetFieldByName passing a string as the
field name and comparing it with a character
//..
(HexxData.GetFieldByName('x8_pos') = str_x[8]) then
if (HexxData.GetFieldByName('o1_pos') = str_o[1]) and
//..
(HexxData.GetFieldByName('o8_pos') = str_o[8]) then
pattern_is_db_current := true;
end; { pattern_is_db_current }
{---------------------------------------------------------}
procedure Thxboard.Find_pattern(var pattern1: pattern_type;
var found: boolean);
begin
//,,
HexxData.GotoNext;
// I need to Goto the Next record
end; { Find_pattern }
{---------------------------------------------------------}
procedure Thxboard.write_updated_pattern(var pattern1: pattern_type);
var
found: boolean;
begin
found := false;
if pattern_is_db_current(pattern1) then
{ save pattern options to db }
begin
save_options(pattern1);
hexxdata_rec_no := HexxData.RecNo;
// I need to Get the Record #
close_db;
if trace_moves then
//..
open_db;
HexxData.GotoRecord(hexxdata_rec_no);
// then I need to Goto to record #
end
else
{ save entire pattern to db };
begin
while (not HexxData.EOF) and not found do
// and test the Dbase.EOF (end of file)
begin
//..
end;
if not found then
begin
{ --- add a new record --- }
HexxData.AppendBlank;
// and Append a Blank record
save_options(pattern1);
HexxData.UpdFieldStr('this_game', inttostr(pattern.this_game));
// save an integer to a Field
//..
hexxdata_rec_no := HexxData.RecNo;
close_db;
if trace_moves then
//..
open_db;
HexxData.GotoRecord(hexxdata_rec_no);
// and Goto to the Record number
end; // if found
end; // else
end; { write_updated_pattern }
{---------------------------------------------------------}
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Since 1970 with a Commodore PET 4016 with 16 KRAM
http://pews-freeware-games.org (<--- brand new)
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