delete method

Future<int> delete(bool where(Row))

Delete rows matching where. Returns affected count.

Implementation

Future<int> delete(bool Function(Row) where) async {
  int count = 0;
  for (final pid in await _allPageIds()) {
    final rows      = await _readPageRows(pid);
    final remaining = <Row>[];
    bool changed    = false;
    for (final row in rows) {
      if (where(row)) {
        for (final entry in indexes.entries) {
          final v = row[entry.key];
          if (v != null) entry.value.delete(v, row.id);
        }
        count++;
        changed = true;
      } else {
        remaining.add(row);
      }
    }
    if (changed) {
      await _writePageRows(pid, remaining);
      meta.rowCount = (meta.rowCount - count).clamp(0, 999999999);
    }
  }
  return count;
}