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How do you iterate over the cursor in reverse order

Usually, when I iterate over the cursor, I use something like the following:

while (cursor.moveToNext()) {
    // get stuff from the cursor    
}

What's the best way to iterate over an Android Cursor? has an enjoyable discussion of the various options. But now I need to go back from the first to the first cursor.

So what can I do?

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2 answers


There are at least two options.

First, to specifically answer your question about iterating backwards on a cursor, you can do the following:

for (cursor.moveToLast(); !cursor.isBeforeFirst(); cursor.moveToPrevious()) {
    // get stuff from the cursor 
}


Second, you can fill the cursor in reverse order from sql and then move the cursor in the usual way:

SQLiteDatabase db = myHelper.getWritableDatabase();
String[] columns = { MyDatabaseHelper.TEST_DATE, MyDatabaseHelper.SCORE };
String orderBy = MyDatabaseHelper.TEST_DATE + " DESC"; // This line reverses the order
Cursor cursor = db.query(MyDatabaseHelper.TESTS_TABLE_NAME, columns,
        null, null, null, null, orderBy, null);

while (cursor.moveToNext()) {
    // get stuff from the cursor
}

cursor.close();
db.close();
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You can start the cursor at the last position and use moveToPrevious () until you're done.



cursor.moveToLast();
do
{
    // Stuff
}
while (cursor.moveToPrevious());
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