Develop Reference

Ionic app suddenly won't open in Android 11

I am building an Ionic 4 App + PouchDB, I have built the app by executing the command ionic cordova run android and for a few days, it works well. Recently though, the app just won't open anymore and I have no idea how to check what went wrong.
Prior to this, whenever something went wrong in the app, I am able to check it using the chrome://inspect. However, with the app not being able to open at all, it's impossible to check the cause of the problem since I am also unable to check using chrome://inspect.
When I tried to run it using ionic cordova run android -l, I get the same result, which is the app loads and closes a few moments later, and I'm still unable to get into chrome://inspect.
I had a hunch that it has something to do with PouchDB. The app starts to behave this way when the storage is almost reaching 200mb. Upon reading the PouchDB FAQ, it's stated;
In PhoneGap/Cordova, you can have unlimited data on both iOS and Android by using the SQLite Plugin.
But I am already using the SQLite Plugin for PouchDB, I have used cordova-sqlite adapter for my PouchDB too.
Below is an example of line in my code:
this._userdb = new PouchDB('user.db', { adapter: 'cordova-sqlite'});
With the app being unable to open, I'm out of ideas on how to retrieve the data stored inside PouchDB since I can't even get into the chrome://inspect at all (I can't see any console.log() for the stored data).
I feel like clearing the app data would allow the app to be opened as how it used to be but I really need to do a backup of the data stored inside PouchDB but I really have no idea how other than getting the console.log() of the data.
Is there any other way I can access the data stored inside the PouchDB to do the backup?

After many failed attempts to figure out how to retrieve the data stored inside PouchDB , I found one solution which is to pull the APK and extract the backup file.
By referring to this article, open CMD and shell into your device by;
adb shell
Provided that you know the app's package name, proceed to pull the APK by running;
adb backup -noapk com.app.your.package.name
**Note: Some devices like Samsung Galaxy stock Android 11 requires password to 'Backup my data'
Once pulled, you will find a backup.ab file and you need to extract this file. At this step, as a Windows user, I was unable to use the openssl method. I get an error using Python too.
But I found a solution that worked well for a Windows user. According to that solution;
Download Android Backup Processor
Go into the directory android-backup-tookit\android-backup-processor\executable (this directory should have a abp.jar file
Copy your backup.ab into this directory.
Open CMD, and run;
java -jar abp.jar unpack backup.ab test.tar
If the device was required password during the backup process, you will be asked to enter password. Enter the same password you provided during backup. Be sure to read the README for further details.
Once done, you will find test.tar file in the same directory. To view the file, simply extract it. The databases created inside the app should be in \test\apps\com.yourappname\f. The sqlite databases files can be viewed using DB Browser for SQLite.

In which folder is my android application?

I created an Android app which is storing some info on the database. I copied .apk file to a folder, clicked on it, it was installed and the app is working. But I cannot find in which folder the app is is located - I want to backup the database. Any ideas?
Thanks,
zb

The app will normally be installed in /data/app directory - it would usually be just the copy of your APK, although not always. The databases, unless you explicitly specified a different location in your code, will be in
/data/data/your.package.name/databases
The package name will be something like com.yourcompany.appname.
Note that backing the data by copying the databases is not the right way to backup your files. Use android backup instead. Also, unless your phone is rooted, you may not be able to get to these databases.

Zalek
Here the location for the app to be searched
MyApp/myapp/build/outputs/apk/myapp-debug.apk
Note: "MyApp" is your project name of your app. I just take an example as myapp

Can't access my android sqlite DB from windows

I have been using an SQLite database in the application I am developing for the android platform. I would like to explore the data from my PC and see the tables and entities. I don't think I have the proper security to access it when I try from the DDMS file explorer on eclipse. I can't open the data folder and when I copy it on my desktop it is empty. Does anyone know how to dump my mobile android SQLite database onto my PC?

You could use cellObject sqlite browser to browse directly from DDMS below is a link to the eclipse plugin: http://www.cellobject.net/Tools/CellObjectSQLiteXMLBrowser.aspx

Without rooting your phone you can get a copy of the DB by running the app on the emulator and then use the DDMS to pull it.from there. It will be the same as if you pulled it off your phone.

You can get DB file your application. Even if your device not rooted.
You must add debug action: copy from \databases\database.db to sdcard. Get database path by getDatabasePath.
From sdcard you can get file by adb pull or File Explorer.
Also you can process back operation: copy from sdcard to app. Of couse you app at device don't
be started.
Иut I have not had any problems, even when the application is running, but there is no access to the base.

Android SQLite path

I am working with SQLite in an App. It writes to the database, etc., with no problem. However, I can not find this new database. I have tried changing the directory with cd /data/data/packageName/databases, but it says "no such file or directory". Also, this database is not found when I click on the File Explorer in eclipse. My logging tells me the database was created and that it is being written to. I think I need to set the path in the shell or something to that effect using adb, but I have no idea how to do that. Can anyone give me some instruction? Also, I am using my phone for development. The database also does not show up when using the emulator.
Thanks very much.
Matt

Matt,
This thread gives a good explanation on why you might not be able to access the data folder on your phone.
Can't access data folder in the File Explorer of DDMS using a Nexus One!
You can still test the Sqlite code though. Just boot up an emulator. The emulator will have no access restrictions. Once it's booted up you can use the ddms tool (located in the tools directory under your android SDK install folder). It has a File Explorer and you can download the files from the /data folder.

Also, I am using my phone for development.
You cannot access the database on a standard Android device except via your own application code.
Your options are:
Do this sort of testing on an emulator, in which case you can access the directory that you are failing to access on the device
Add a database backup feature to your app, that copies the (closed) database to external storage, so you can examine it
Root your phone (leastways, I am under the impression this can help get you to this directory -- haven't done it myself)
The database also does not show up when using the emulator.
Try harder. If you can store data in the database and read data out of it using SQLiteDatabase, then the database file is there.

Where does the android emulator data lies?

Where does the emulator data lie(the contacts, messages, saved images)?

Go to ddms,you can find the file explorer from that you will get application directry and sd card filed you can find all the detailed files there.

In ~/.android (that is your user directory/.android)

Each application stores its own data in its own private folder in /data/data on the emulator. Depending on the application it potentially can also store data on the /sdcard (e.g. downloaded images or whatever) which by convention should then be in /sdcard/Android/data/com.yourappspackage.and.so/ so that it gets cleaned up with uninstall but many apps also throw stuff all over the sd card (although they should not..)
More is on the dev site e.g. at http://developer.android.com/guide/topics/data/data-storage.html
All this is the same for the emulator as well as the real device. The emulator is just a virtual machine running on qemu.

You can use File Explorer tool in eclipse or ddms to View The data in the emulator
else use terminal to view the data using the command,
adb shell
Thank you,
Ganapathy.