applyIfNotAlready method

@override Future<bool> applyIfNotAlready(StmtMigration migration)

Applies the provided migration only if it has not yet been applied. migration: The migration to apply. Returns A future that resolves to a boolean that indicates if the migration was applied.

Implementation

@override
Future<bool> applyIfNotAlready(StmtMigration migration) async {
  final rows = await adapter.query(
    Statement(
      '''
SELECT 1 FROM $migrationsTable
WHERE version = ${queryBuilder.makePositionalParam(1)}''',
      [migration.version],
    ),
  );

  final shouldApply = rows.isEmpty;

  if (shouldApply) {
    // This is a new migration because its version number
    // is not in our migrations table.
    await apply(migration);
  }

  return shouldApply;
}