Where do I save data from a Nokia application?

[ShahriarNK]

I am developing a Nokia application that saves a pair of data - an integer and a date. The application will save thousands of such pairs of data. The data may also be exported as CSV.

What is the best practise for such a scenario?
Do I save it to particular drive on the mobile?
Can I use a resource (qrc) file for this purpose?

Can amount of details will be greatly appreciated. Thanks.

[Nitesh Bhardwaj]

if the amount of data is very big and its accessing is very high, then you can prefer Database,
and for creating the DB, look on that,
http://wiki.forum.nokia.com/index.ph...database_in_Qt

[ShahriarNK]

Thanks for your reply.
I was thinking of saving to a file because only one pair will be saved once/twice every day. Then all the data may be used to generate a graph (once or couple of times a day).

Do you think saving to a file would suffice?
Will using a database make the application faster?

Please advice. Thanks.

[Nitesh Bhardwaj]

Will using a database make the application faster?

yes in that case,it would be good to use DB.

[ShahriarNK]

Thanks Nitesh, just some followup questions...

Do you think the use of a database would make the application too large in size (and it would become difficult to download)?
Also, would it requre the installation of additional software in the user's mobile device?
And would be possible to export the data as CSV from the database?

Your help is very much appreciated!

[Nitesh Bhardwaj]

Do you think the use of a database would make the application too large in size (and it would become difficult to download)?

in your case, the DB will be created and it will use also after installation of your application.so at the time of downloading it wouldn't be any effect on size of application.

Also, would it requre the installation of additional software in the user's mobile device?

no additional s/w will be required.

[danhicksbyron]

You can certainly write to a plain old file, if that suits your needs. It would be faster than using a DB, and take up less space.

Generally, unless you want to share the data with other applications on the phone, you should place it in the "private" directory of the application. You do this by simply opening a file with no directory root specified -- the app starts out with "cd" set to this directory.

If you want to share the data with other applications, or make it accessible via the USB, you should place it in C:/Data/your-app-directory on Symbian -- not sure about Maemo.

You can't write to a resource file.

[achipa]

If it's just local data, and really low volume (i.e. not more than a few hundred pairs) the easiest way is putting it a QSettings - that automatically takes care about directories, drives, etc

[ShahriarNK]

Generally, unless you want to share the data with other applications on the phone, you should place it in the "private" directory of the application. You do this by simply opening a file with no directory root specified -- the app starts out with "cd" set to this directory.

Thanks very much for the info Dan.
I have one follow-up query: my application will save the data to a file as well as read from it. So, if I open a file with no root specified, how do I find/locate the file when I want to read from it?

Thanks again.

[petrib]

When you create a file without specifying a path and write to it, logic dictates that if you use the same name to open it later for reading, it will be located from the same default directory. I.e., you don't really need to find/locate it yourself.

[achipa]

When you create a file without specifying a path and write to it, logic dictates that if you use the same name to open it later for reading, it will be located from the same default directory. I.e., you don't really need to find/locate it yourself.

That's generally true for absolute paths, relative paths are... relative (so not as reliable as your working directory might change). Some platforms might also have their limitations of their own that might show as 'missing' files (for example under Maemo/MeeGo your file will not be available if it was in MyDocs and the device is connected to a PC in mass storage mode).

[danhicksbyron]

Yeah, it would have helped if the OP had revealed what platform he's running on.