page method

Future<MssqlPage<TRow>> page({ int size = 25, int offset = 0, bool total = false, MssqlReadConsistency consistency = MssqlReadConsistency.committed, })

One OFFSET page, and whether another follows.

Fetches size+1 and drops the extra row before include, so relations are not loaded for a parent that is not on the page. total runs a second count over the same filter/scope; consistency snapshot puts both (and includes) in one SNAPSHOT transaction.

Implementation

Future<MssqlPage<TRow>> page({
  int size = 25,
  int offset = 0,
  bool total = false,
  MssqlReadConsistency consistency = MssqlReadConsistency.committed,
}) async {
  if (offset < 0) {
    throw ArgumentError.value(offset, 'offset', 'Cannot be negative.');
  }
  if (size <= 0) {
    throw ArgumentError.value(size, 'size', 'Must be positive.');
  }
  final ordered = ensureStableOrder();
  final dialect = await _resolvedDialect();
  // One snapshot for the page, its includes and its total: a tenant scope
  // resolved twice could count one tenant's rows against another's page.
  final scopes = ordered.context.scopeCompiler(ordered.state.scope);
  final loader = ordered._loaderFor(session, dialect);
  return mssqlRunConsistent(
    session: session,
    consistency: consistency,
    body: (s) async {
      final fetched = await ordered
          ._select(scopes: scopes)
          .paged(offset: offset, rows: size + 1)
          .get(
            s,
            dialect: dialect,
            timeout: state.options.timeout,
            cancellationToken: state.options.cancellationToken,
            options: state.options,
          );
      final mapped = fetched.map(binding.fromRow).toList();
      final hasMore = mapped.length > size;
      final slice = ordered.dropPageSentinel(mapped, size);
      final parents = await ordered._attachOn(
        s,
        slice,
        dialect: dialect,
        loader: loader.withSession(s),
      );
      return MssqlPage<TRow>(
        rows: parents,
        offset: offset,
        requestedRows: size,
        hasMore: hasMore,
        total: total
            ? await ordered._countOn(s, dialect: dialect, scopes: scopes)
            : null,
      );
    },
  );
}