ORMLite with CursorAdapter in Android

Question

I am modifying my Android app to work with ORMLite, and it currently uses a number of CursorAdapters, which I quite want to keep in an attempt to minimise coding.

I\

Answer 1

Your comments indicate that you've already answered you problem. You can certainly create a column named "_id" using ORMLite:

@DatabaseField(generatedId = true)
private int _id;

or

@DatabaseField(generatedId = true, columnName = "_id")
private int id;

If you are working with Cursors then you may want to take a look at the last() and moveAbsolute(...) methods on the DatabaseResults class. Also, the AndroidDatabaseResults (which you can cast to) also has a getRawCursor() method which returns the underlying Cursor object and has additional getCount() and getPosition() methods.

Here are some more information about ORMLite and Cursors:

Android Cursor with ORMLite to use in CursorAdapter

You can get access to the Cursor using something like the following:

// build your query
QueryBuilder<Foo, String> qb = fooDao.queryBuilder();
qb.where()...;
// when you are done, prepare your query and build an iterator
CloseableIterator<Foo> iterator = dao.iterator(qb.prepare());
try {
   // get the raw results which can be cast under Android
   AndroidDatabaseResults results =
       (AndroidDatabaseResults)iterator.getRawResults();
   Cursor cursor = results.getRawCursor();
   ...
} finally {
   iterator.closeQuietly();
}

Answer 2

Wrap your cursor with another one that treats "_id" as an alias to your real primary key column. Example:

cursor = new CursorWrapper(cursor) {
                @Override
                public int getColumnIndexOrThrow(String columnName) throws IllegalArgumentException {
                    if ("_id".equals(columnName)) columnName = "id";
                    return super.getColumnIndexOrThrow(columnName);
                }
            };

Answer 3

It turns out I did need a raw SQL query with ORMLite after all as I needed to do a Left Join, (i.e. not as a result of having to rename the id column in a query, that is not necessary as per Gray's answer above)

The way I did it is below:

public class DatabaseHelper extends OrmLiteSqliteOpenHelper{
   public void myRawQueryMethod() {
        SQLiteDatabase database = this.getReadableDatabase();
        String SqlQuery = "Write raw SQL query here"; 
        Cursor cursor = database.rawQuery(SqlQuery, null);
    }
}

Thanks for advice