Question

I’m trying to have a menu button to clear my database when it is pressed. That works well as far as I can tell. However, as soon as new information is sent to the database, the app force closes. How should I stop this?
Here is the clear part:

@Override 
public boolean onMenuItemSelected(int featureId, MenuItem item) {
    switch(item.getItemId()) {
        case INSERT_ID:
//reset just makes all the variables in the thread reinitialize at base values
            mLemonadeMainMenuView.reset(); 
            NotesMade = 0;
            mDbHelper.deleteAllNotes();
            return true;
    }

Here is deleteallnotes():

public boolean deleteAllNotes() { return mDb.delete(DATABASE_TABLE,"1", null) > 0; }

Here is the new data information:

  @Override
    public boolean onTouchEvent(MotionEvent event) {
        mDbHelper.createNote(event.getX(), event.getY(), 1);
        NotesMade ++;
        mLemonadeMainMenuView.setCoords(NotesMade);
        return true;
    }

Finally, here is the receiving end:

         while(mNotesMade>mNoteId)
            {mNoteId++;
             Cursor note = mDbHelper.fetchNote(mNoteId);
             Float x;
             Float y;
             Float size;
             x = Float.valueOf(note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_X)));
             y= Float.valueOf(note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_Y)));
             size =Float.valueOf(note.getString(note.getColumnIndexOrThrow(NotesDbAdapter.KEY_X)));
      canvas.drawCircle(x, y, 1, paint);}
}

Note: I have already tried starting and stopping the thread in addition to the above.

Logcat:12-30 11:51:29.812: E/AndroidRuntime(6311): FATAL EXCEPTION: Thread-10
12-30 11:51:29.812: E/AndroidRuntime(6311): android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
12-30 11:51:29.812: E/AndroidRuntime(6311):     at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:214)
12-30 11:51:29.812: E/AndroidRuntime(6311):     at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
12-30 11:51:29.812: E/AndroidRuntime(6311):     at com.drawing.LemonadeMainMenuView$LemonadeMainMenuThread.doDraw(LemonadeMainMenuView.java:75)
12-30 11:51:29.812: E/AndroidRuntime(6311):     at com.drawing.LemonadeMainMenuView$LemonadeMainMenuThread.run(LemonadeMainMenuView.java:52)

Edit: solved – see Community Wiki answer.

Answer 1

In SQL, you arrange to execute:

 DELETE FROM YourTable;

or:

 DELETE FROM YourTable WHERE 1=1;  -- If your DBMS does not like unconstrained deletes

or:

 TRUNCATE TABLE YourTable;

On the face of it, the mDb.delete() method drops the table rather than deleting the data from the table. There’s a reason why SQL uses CREATE and DROP separately from INSERT, DELETE and UPDATE.