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Question

Cursor while loop returning every value but the last

Answer 1

+4 A:

Your skipping the first value actually, not the last.

trackCursor.moveToFirst();
while (trackCursor.moveToNext()) {

The first time into the while loop you are pointing at the 2nd row.

I would convert your while loop to a do-while loop

mbaird 2010-04-02 15:54:27

I tried the do while, but as the number of rows returned could be any number I wasn't sure what the while expression should be?

LordSnoutimus 2010-04-02 16:23:41

do {...} while (trackCursor.moveToNext()) It's the same while expression that you are currently using.

mbaird 2010-04-02 16:47:22

Answer 2

+1 A:

Cursor c=null;
c=......;
try {
    if (c!=null) {
        for (c.moveToFirst(); !c.isAfterLast(); c.moveToNext()) {

        }

    }
} finally {
    if (c!=null) {
        c.close();
    }
}

Pentium10 2010-04-02 16:29:12

Answer 3

+5 A:

moveToNext() has two features. It returns a boolean signifying that there is a next, but at the same time it goes ahead and moves the cursor.

public void loadTrack() {
SQLiteDatabase db1 = waypoints.getWritableDatabase();
Cursor trackCursor = db1.query(TABLE_NAME, FROM, "trackidfk=1", null, null, null,ORDER_BY); 

    trackCursor.moveToFirst();
    do {
        Double lat = trackCursor.getDouble(2);
        Double lon = trackCursor.getDouble(1);
        //overlay.addGeoPoint( new GeoPoint( (int)(lat*1E6),  (int)(lon*1E6)));
        System.out.println(lon);
        System.out.println(lat);
    } while (trackCursor.moveToNext());
}

Parker 2010-04-02 16:40:17

Make sure you use try catch.

Pentium10 2010-04-02 17:00:38

You probably want something in to make sure there is a first element though, that probably won't go too well if it ever ends up in an empty one.

AaronM 2010-04-03 00:31:20

Answer 4

A:

You just executed the query. Can't you just get rid of the moveToFirst()?

public void loadTrack() {
SQLiteDatabase db1 = waypoints.getWritableDatabase();
Cursor trackCursor = db1.query(TABLE_NAME, FROM, "trackidfk=1", null, null, null,ORDER_BY); 

    while (trackCursor.moveToNext()) {
        Double lat = trackCursor.getDouble(2);
        Double lon = trackCursor.getDouble(1);
        //overlay.addGeoPoint( new GeoPoint( (int)(lat*1E6),  (int)(lon*1E6)));
        System.out.println(lon);
        System.out.println(lat);
    }
}

Wayne Young 2010-04-03 00:26:42

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Cursor while loop returning every value but the last

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