how to remove Database or drop table when uninstall

[Dynasty1215]

hi,
in my application runing, the qml(js) open database used openDatabaseSync("xxxx", "1.0", "xxxx SQL", 10000); and create some tables, save some datas.
now, when the application uninstall, i want clear the datas that saved in the database. but i don't know how to.

The probloms are:
1.how to set when uninstalling run some exe(or, scrip) i.e, to do something;
2.how to the the exe(scrip) clear the data (drop table or remove database)

or, give some other suggestion.

pls help . thx first. :-)

[kusumk]

Hi,

Please use debian maintainer scripts for running scripts at the time of pre/post installation or pre/post uninstallation.

For deleting files on installation you can write a postrm or prerm script and put in dir qtc_packaging/debian_harmattan

http://www.debian.org/doc/debian-pol...erscripts.html

Threads earlier related to similar topic - http://www.developer.nokia.com/Commu...llation-of-app

http://www.developer.nokia.com/Commu...ghlight=postrm

Some examples available at - http://talk.maemo.org/showthread.php?t=80947

Let us know if you have any problems

[gnuton]

I think we need to write a wiki page which cover this topic....

[Dynasty1215]

Sorry beeing late
Thanks for kusumk and gnuton
I think the postinst , prerm is useful for me, and now i'am trying use postinst to mkdir when after the application installed
But, i have a trouble that when the script run, it return a error:

aegis-installing qtAppmobile (from '')
Setting up qtAppmobile (1.1.3) ..
mkdir: can't create directory '/opt/DBOPTTest/temp': No such file or directory
Processing triggers for desktop-file-utils ...
dpkg: error processing qtAppmobile (--install):
subprocess installed post-installation script returned error exit status 1

In my postinst file, the script are:
#!/bin/sh

set -e

if [ -d "/opt/DBOPTTest/db" ]; then
echo "Folder exists!"
else
mkdir /opt/DBOPTTest/db
chmod -R 777 /opt/DBOPTTest/db
fi

I don't know why have error.
Any help?
Thx!

[kusumk]

Hi,

That is because when you uninstall your app /opt/<yourapp> folder is removed.

If you try to create a folder inside that after removal, it would give error. BTW, Why are you trying to create a dir after uninstallation?

[Dynasty1215]

Thanks kusumk
I want to create a dir after installed, not uninstallation.
I want to create a dir after installed, then, I used the viewer->engine()->setOfflineStoragePath(QString) function for the database dir. In my app(qml), I used openDatabaseSync() open db, create table, save some datas.
And I want remove the database dir when uninstall the app, that, I think the prerm file can useful for me.
Is that ?

[Dynasty1215]

Now i am useing postinst want to mkdir after install my application
But there is an error when mkdir. The error is:

aegis-installing qtAppmobile (from '')
Setting up qtAppmobile (1.1.3) ..
mkdir: can't create directory '/opt/DBOPTTest/temp': No such file or directory
Processing triggers for desktop-file-utils ...
dpkg: error processing qtAppmobile (--install):
subprocess installed post-installation script returned error exit status 1

In My postinst file , the scripts are:
#!/bin/sh

set -e

if [ -d "/opt/DBOPTTest/db" ]; then
echo "Folder exists!"
else
mkdir /opt/DBOPTTest/db
chmod -R 777 /opt/DBOPTTest/db
fi

Any helps?

[mikkovtr]

does /opt/DBOPTTest exist?

try "mkdir -p /opt/DBOPTTest/db", it will create missing parent directories.

edit: Nevermind, error is from /opt/DBOPTTest/temp, where is this directory coming from?

[Dynasty1215]

Hi, mikkovtr
I am sorry, I make a misstake.
The error infos are: "mkdir: can't create directory '/opt/DBOPTTest/db': No such file or directory", not "mkdir: can't create directory '/opt/DBOPTTest/temp':". You are very careful.
Now, I am useing "mkdir -p /opt/DBOPTTest/db", that's ok.
I am unknowing the scripts about linux, that's the key. ;-)
Who can tell me, where are the more details about the scripts(parameters) likes "mkdir" "-p" etc.
Thx everyone

[mikkovtr]

I don't know any single source, but if you search for "linux shell scripting" or "shell scripting" and you'll find plenty of tutorials. For any particular command, like mkdir, you can search for "man mkdir" to read manual pages. And if you have Linux then type "man mkdir" to your shell.

I don't want to distract you but usually user created content is stored in user's home directory. Directories can be created also by listing them in debian/dirs file, but it will not get removed files are left behind there.

[Dynasty1215]

I don't know more about linux dir systerm, so i don't understant the "home" "user" "opt" .e.g and their relations.

I used postinst mkdir (/opt/DBOPTTest/db) when installing. I used offlineStoragePath(const QString& ) function set the offline storrage path. Then I used function openDatabaseSync, then create table, save datas.

I want used prerm to remove the dir or drop the database when the app uninstalling.

Now, the prerm is invalid. After i uninstall the app, the dir existence.

I can saw the dir uesd Terminal on my n950 devices.

In the /opt/DBOPTTest/db/Databases (the subdir "Databases" is generat auto)there are tow files:
ec0b4428c9cc8f4e05969d699e4e814e.ini
ec0b4428c9cc8f4e05969d699e4e814e.sqlite
I thinkd , that is I want clear.

In my prerm file:
rm -f /opt/DBOPTTest/db

But it is invalid.

Any good idea for me ?

[mikkovtr]

This should be good read on file locations.
http://harmattan-dev.nokia.com/docs/...a_storage.html

But to the problem. I believe you would like to remove /opt/DBOPTTest directory completely. To achieve that use "rm -rf /opt/DBOPTTest". This will recursively remove /opt/DBOPTTest directoctory and every file and subdirectory it contains.

[Dynasty1215]

This should be good read on file locations.
http://harmattan-dev.nokia.com/docs/...a_storage.html

But to the problem. I believe you would like to remove /opt/DBOPTTest directory completely. To achieve that use "rm -rf /opt/DBOPTTest". This will recursively remove /opt/DBOPTTest directoctory and every file and subdirectory it contains.

Sorry, so long time i have'd to here.
I am solved it , "rm -rf /opt/DBOPTTest" is ok. Before i had error,"Permission denied", the reason is the "permissions " not enough.
I added <request context="INSTALL">
<credential name="UID::user" />
<credential name="GID::users" />
</request>

in the manifest.aegis. It's ok.
Thx everyone again, :-)