Sqlite databse corruption

[karmac2015]

Hello,

I use your plugin in my ionic application on android platform , and I have a plugin that uses the SQLiteDatabase class to work with the database created by your plugin.
But when my java code access the database in the same time when I access the database from javascript using your plugin, the app crashes and the database is corrupted.
Please help me to solve this problem.

[brodycj]

As discussed in #626:

From http://ericsink.com/entries/sqlite_android_n.html: in case someone android.database.sqlite from another plugin or application-specific Java code to access the same database as this plugin there is potential for database corruption ref:

• https://www.sqlite.org/howtocorrupt.html
• http://ericsink.com/entries/multiple_sqlite_problem.html

Note that the first part about "SQLite and Android N" is NOT a problem with this plugin since it uses its own build of SQLite.

In case anyone encounters this issue the workaround is to open the database with the androidDatabaseImplementation: 2 and possibly androidLockWorkaround: 1 settings as documented.

Will be documented soon.

[karmac2015]

In my java plugin I use the following code:

SQLiteDatabase db = SQLiteDatabase.openDatabase(path, null, 0);
ContentValues values = new ContentValues(); 
values.put("Name", queryValues.get("name"));
db.insert("student", null, values);

If there are multiple threads that access the database in the same time, is your solution solve the problem ?
What about using db.enableWriteAheadLogging() in this situation ?
How can I get the connection opened by your plugin in my java plugin ?

[brodycj]

values.put("Name", queryValues.get("name"));

What is queryValues?

If there are multiple threads that access the database in the same time, is your solution solve the problem ?

Yes, assuming that there is not a bug in the builtin android.database implementation. This may depend on which Android version and maybe which system build is installed on the device.

What about using db.enableWriteAheadLogging() in this situation ?

I have not looked at this one. In general I do not really favor WAL (write ahead logging ref: https://www.sqlite.org/wal.html) since it would require the overhead of checkpointing at certain intervals. I also just discovered an interesting issue at http://stackoverflow.com/questions/39149065/sqlite-write-ahead-logging-wal-journal-mode-with-attached-database.

How can I get the connection opened by your plugin in my java plugin ?

I recommend that you look in the dbmap at https://github.com/litehelpers/Cordova-sqlite-storage/blob/storage-master/src/android/io/sqlc/SQLitePlugin.java#L39 and follow the objects until you get the SQLiteDatabase connection.

Please report if these answers help solve your problem or not.

[brodycj]

Another solution may be to use an Android content provider to store and retrieve data as discussed in storesafe/cordova-sqlite-storage-help#9:

it may be possible to use a content provider with https://github.com/phearme/cordova-ContentProviderPlugin to store and access data from both JavaScript and custom Java code. I found a couple nice looking tutorials at:

• https://www.tutorialspoint.com/android/android_content_providers.htm
• http://www.vogella.com/tutorials/AndroidSQLite/article.html (more specific to SQLite)

[brodycj]

Closing as invalid with info needed due to lack of response. Please feel free to ask here or in a new issue if you have any more questions.