database without external file

[azaky]

I want to make a database that is editable without the need of any external files. Is there any option to make it?

[User137]

So basically you want to modify the executable while it's running? I don't really know any database or storage method that isn't stored in a separate file somewhere. Even when using Windows registry it is a file in the end, but less visible one.

[JanRoza]

And using a modifying-itself program file I think antivirus programs will have a field day.
Program files shouldn't be modified, data should be separate from your program (my humble opinion).
How do you plan to upgrade your program when a user already is using the older version for some time without loosing his data?

[azaky]

hmm, so it is impossible to do so? Actually I always wonder how, for example, those mini games which (apparently) only have a single executable file, but it can save things such as highscores. I thought lazarus can do the same thing.

[JuhaManninen]

hmm, so it is impossible to do so? Actually I always wonder how, for example, those mini games which (apparently) only have a single executable file, but it can save things such as highscores. I thought lazarus can do the same thing.

Those games can make a hidden file to user's home directory or they can use Windows registry. You could do the same.
A program can also store user's profile data to a server through internet connection.

Juha

[fredycc]

Many times the file is created when you launch the application on any current user's path also has hidden attributes, sometimes if the game is through a login before you download a file with the most recent game items or cookies if they are web applications like JuhaManninen suggest you, if we talk about data sets could be in a single XML file only.

Regards

[azaky]

thanks for the replies guys! I am very new in programming with lazarus, so I don't know so much about databases.
btw making files invisible is a good idea, but how to set that file to be invisible?

[TurboRascal]

Also remember that you should not store data in the program directory unless really necessary. Doing that essentially makes the program unusable for limited users, and is a bad practice.

[Leledumbo]

how to set that file to be invisible?

under *nix: start the filename with . (dot)
under windows: change the hidden attribute to true

[azaky]

how to set that file to be invisible?

under *nix: start the filename with . (dot)
under windows: change the hidden attribute to true

Do you mean by setting the file properties? After googling, I found that it can be done with FileSetAttr. But now I have another problem. Each time I want to retrieve data from hidden files, it always returns RunError(5). Should I set the file to be not hidden each time I want to read it?

[Leledumbo]

http://www.freepascal.org/docs-html/user/userap4.html
See error code 5.

Should I set the file to be not hidden each time I want to read it?

It shouldn't be the problem, but worth trying.