When Does Sqliteopenhelper Oncreate()/Onupgrade() Run

When does SQLiteOpenHelper onCreate() / onUpgrade() run?

SQLiteOpenHelper onCreate() and onUpgrade() callbacks are invoked when the database is actually opened, for example by a call to getWritableDatabase(). The database is not opened when the database helper object itself is created.

SQLiteOpenHelper versions the database files. The version number is the int argument passed to the constructor. In the database file, the version number is stored in PRAGMA user_version.

onCreate() is only run when the database file did not exist and was just created. If onCreate() returns successfully (doesn't throw an exception), the database is assumed to be created with the requested version number. As an implication, you should not catch SQLExceptions in onCreate() yourself.

onUpgrade() is only called when the database file exists but the stored version number is lower than requested in the constructor. The onUpgrade() should update the table schema to the requested version.

When changing the table schema in code (onCreate()), you should make sure the database is updated. Two main approaches:

1. Delete the old database file so that onCreate() is run again. This is often preferred at development time where you have control over the installed versions and data loss is not an issue. Some ways to delete the database file:

   • Uninstall the application. Use the application manager or adb uninstall your.package.name from the shell.

   • Clear application data. Use the application manager.

2. Increment the database version so that onUpgrade() is invoked. This is slightly more complicated as more code is needed.

   • For development time schema upgrades where data loss is not an issue, you can just use execSQL("DROP TABLE IF EXISTS <tablename>") in to remove your existing tables and call onCreate() to recreate the database.

   • For released versions, you should implement data migration in onUpgrade() so your users don't lose their data.

SQLiteOpenHelper onCreate method is not called

public class Database extends SQLiteOpenHelper {
    public static SQLiteDatabase db;
    public Database(Context context) {
        super(context,"db", null, 1);
        getReadableDatabase(); // <-- add this, which triggers onCreate/onUpdate
        Log.i("DB", "dbManager");
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        Log.i("DB", "dbOnCreate");
        // ...
    }
    // ...
}

Explanation:
The update is only triggered if the db is accessed for writing or reading. Since you don't attempt that, onCreate is never called.

Usually, you would just call a method of your Database class somewhere (for example for querying entities) and that is the moment when onCreate/(or onUpdate) would be called.

Since, you don't have such methods (for now), just call it inside the Database constructor.

Or:

Alternatively, and maybe more clean would be to call getReadableDatabase() right after the creation of your Database object:

Database db = new Database(this);
db.getReadableDatabase();

When the SQLiteOpenHelper onCreate method is called?

The documentation says:

The database is not actually created or opened until one of getWritableDatabase() or getReadableDatabase() is called.

SQLiteOpenHelper not calling onCreate

In SQLiteOpenHelper, the meaning of 'onCreate' is different from what it is in an Activity. Here,'onCreate' is called only once, which is the first time you create the database. The next time you run the app, the database is already there, so it won't call 'onCreate'. Your object level initialization should be done in the constructor and not in 'onCreate'

To see 'onCreate' being called, either manually delete the db file, or simply uninstall the app.

onUpgrade is not being called at first time in android SQLiteOpenHelper

Likely the database you're copying as the initial database already has it's schema version as 2.

Some other issues:

• You should store the result of getWritableDatabase() or getReadableDatabase() and close() it when done.

• This

  DB_PATH = "/data/data/" +
           context.getPackageName()+
      "/databases/"
  

  won't work on all devices. Don't hardcode database paths. Use getDatabasePath() instead.

When is a SQLite database initially created in Android?

Database, as file on disk, is created when you call getWritableDatabase or getReadableDatabase.

Just read the docs of SQLiteOpenHelper constructor ;-)

SqliteOpenHelper onCreate() method changes being ignored

If you made changes after the database was already made, then you must update the database version number and setup the onUpgrade method to drop and recreate the tables.

You can also remove some parameters from the constructor since they aren't used.

public CardDBHandler(Context context, SQLiteDatabase.CursorFactory factory) {
    super(context, CARD_DATABASE_NAME, factory, CARD_DATABASE_VERSION);
}

Then

cardDBHandler = new CardDBHandler(this, null);

onUpgrade and onCreate not being called after changing android.database.sqlite.SQLiteOpenHelper to net.sqlcipher.database.SQLiteOpenHelper

Finally I found the solution for the problem. Instead of calling the migration functionality inside the onUpgrade() method, I added the migration code before the database is queried for the first time (after opening the app):

public static void encrypt(Context ctxt, File originalFile, char[] 
passphrase)
throws IOException {
SQLiteDatabase.loadLibs(ctxt);

if (originalFile.exists()) {
  File newFile=
  File.createTempFile("sqlcipherutils", "tmp", ctxt.getCacheDir());
   SQLiteDatabase db=
   SQLiteDatabase.openDatabase(originalFile.getAbsolutePath(), "", null, SQLiteDatabase.OPEN_READWRITE);

   db.rawExecSQL("ATTACH DATABASE '" + newFile.getAbsolutePath()+ "' AS encrypted KEY '"+String.valueOf(passphrase)+"'");
   db.rawExecSQL("SELECT sqlcipher_export('encrypted')");
   db.rawExecSQL("DETACH DATABASE encrypted");

   int version=db.getVersion();

    db.close();

    db=SQLiteDatabase.openDatabase(newFile.getAbsolutePath(), passphrase, null, SQLiteDatabase.OPEN_READWRITE);
    db.setVersion(version);
    db.close();

    originalFile.delete();
    newFile.renameTo(originalFile);
  }
}

I took the solution from this source. Thanks for the author, whoever he is!

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