code: private int updDel(int op, Uri uri, ContentValues vals, String sel, String[] args) {
          /* get the IDs of records that will be affected */
          Sql sql = elements(op, uri, new String[]{"rowid"}, sel, args, null);
          long[] ids = Cursors.allLongs(sql.mResult);
          /* update or delete the records and then notify about any changes */
          SQLiteDatabase db = mHelper.getWritableDatabase();
          int rows = op == UPDATE ? db.update(sql.table(), vals, sql.sel(), sql.args())
                  : db.delete(sql.table(), !TextUtils.isEmpty(sql.sel()) ? sql.sel() : "1",
                          sql.args());
          if (rows > 0) {
              for (long id : ids) {
                  notifyChange(ContentUris.withAppendedId(sql.notifyUri(), id), uri);
              }
          }
          return rows;
      }
docs: Update or delete records and get the number of rows affected.