UseRowClass class

An annotation specifying an existing class to be used as a data class.

By default, drift generates a row class as a typed representation of a row in the table classes you define. If you want to, you can replace this row class with your own structure by applying UseRowClass on the table:

@UseRowClass(User)
class Users extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text()();
}

final class User {
  final int id;
  final String name;

  User(this.id, this.name);
}

The associated row class must have a constructor "compatible" with the columns from the table (meaning that each parameter on the constructor matches a column from the table by name and type). Not all columns present in the table need to be added to the row class, drift will simply ignore the others. Since drift constructs the row class from a table row however, the constructor must not have parameters not present as table columns.

Instead of an existing class, you can also use Record or a record type through a typedef as a type to use for rows:

typedef User = ({int id, String name});

@UseRowClass(User)
class Users extends Table {

If you want to use instances of your custom row classes as sources for inserts or update statements, you can enable the write_to_columns_mixins builder option or set generateInsertable to true. It will make drift generate an extension on the row type to return a companion:

@UseRowClass(User, generateInsertable: true)
class Users extends Table {
  IntColumn get id => integer().autoIncrement()();
  TextColumn get name => text()();
}

final class User implements Insertable<User> {
  final int id;
  final String name;

  User(this.id, this.name);

  @override
  Map<String, Expression> toColumns(bool nullToAbsent) {
    return toInsertable().toColumns(nullToAbsent);
  }
}

For more details, see the documentation page.