single method
Executes the mutation and requires exactly one returned row.
Throws QUERY.CARDINALITY after execution if the result is empty or has
multiple rows. Use a transaction if that failure must roll back the write.
Implementation
Future<R> single({
ExecutionOptions options = const ExecutionOptions(),
}) async {
final result = await get(options: options);
if (result.length != 1) {
throw OrmException(
'QUERY.CARDINALITY',
'Expected one returned row, received ${result.length}.',
);
}
return result.single;
}