count<Row extends Object, RS extends ResultSet<Row, RS>> method

SingleSelectable<int> count<Row extends Object, RS extends ResultSet<Row, RS>>(ResultSet<Row, RS> table, { Expression<bool> where(RS row)?, })

Counts the amount of rows in a table.

The optional where clause can be used to only count rows matching the condition, similar to SingleTableSelectStatement.where.

The returned Selectable can be run once with Selectable.getSingle to get the count once, or be watched as a stream with Selectable.watchSingle.

Implementation

SingleSelectable<int> count<
  Row extends Object,
  RS extends ResultSet<Row, RS>
>(ResultSet<Row, RS> table, {Expression<bool> Function(RS row)? where}) {
  final count = countAll();
  final stmt = selectOnly(table).addColumns([count]);
  if (where != null) {
    stmt.where(where(table.asSelfType()));
  }

  return stmt.map((row) => row.read(count)!);
}