In the first version of my database, I had three rows. The following methods apply to a class that extends SQLiteOpenHelper.
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL("CREATE TABLE " + DATABASENAME + " (name TEXT, latitude REAL, longitude REAL);");
}
Now I changed the version number from 1 to 2 and added a new line:
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL("CREATE TABLE " + DATABASENAME + " (name TEXT, latitude REAL, longitude REAL, country TEXT);");
}
I donβt care that the old database is lost, so I use it when updating:
@Override
public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
db.delete(DATABASENAME, null, null);
onCreate(db);
}
Now, when I call the method getReadableDatabase(), the application crashes with a logcat error
Raised: android.database.sqlite.SQLiteException: unable to update read-only database from version 1 to 2: /data/data/com.myapp.app/databases/mydb
How can I prevent this?
EDIT
Full class:
public class StationsOpenHelper extends SQLiteOpenHelper {
private static final String DATABASENAME = "stations";
private static final int DATABASEVERSION = 2;
public StationsOpenHelper(Context context) {
super(context, DATABASENAME, null, DATABASEVERSION);
}
@Override
public void onCreate(SQLiteDatabase database) {
database.execSQL("CREATE TABLE " + DATABASENAME + " (name TEXT, latitude REAL, longitude REAL, country TEXT);");
}
@Override
public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
db.delete(DATABASENAME, null, null);
onCreate(db);
}
public ArrayList<Station> getStations() {
Logger.log("Trying to read stations from database");
ArrayList<Station> result = new ArrayList<Station>();
SQLiteDatabase database = getReadableDatabase();
Cursor cursor = database.rawQuery("SELECT * FROM " + DATABASENAME, null);
String name, country;
double lat, lon;
Station s;
cursor.moveToFirst();
while (!cursor.isAfterLast()) {
s = new Station();
name = cursor.getString(0);
lat = cursor.getDouble(1);
lon = cursor.getDouble(2);
country = cursor.getString(3);
s.setName(name);
s.setLatitude(lat);
s.setLongitude(lon);
s.setCountry(country);
result.add(s);
cursor.moveToNext();
}
cursor.close();
database.close();
if (result.isEmpty()) {
Logger.log("Reading stations from database failed");
result = null;
} else {
Logger.log("Reading stations from database succeeded");
}
return result;
}
public void storeStations(ArrayList<Station> stations) {
Logger.log("Storing stations in database");
ContentValues values = new ContentValues();
SQLiteDatabase db = getWritableDatabase();
db.delete(DATABASENAME, null, null);
for (int i = 0; i < stations.size(); i++) {
values.put("name", stations.get(i).getName());
values.put("latitude", stations.get(i).getLatitude());
values.put("longitude", stations.get(i).getLongitude());
values.put("country", stations.get(i).getCountry());
db.insert(DATABASENAME, null, values);
}
db.close();
Logger.log("Storing stations in database succeeded");
}
}