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perlresultsetdbix-class

What is differences between ResultSet and an object?

From DBIx::Class::ResultSet we read that:

WARNING
If called on an object, proxies to "new_result" instead, so
my $cd = $schema->resultset('CD')->new({ title => 'Spoon' });
will return a CD object, not a ResultSet, and is equivalent to:
my $cd = $schema->resultset('CD')->new_result({ title => 'Spoon' });

Could someone explain what is differences between object and ResultSet?

Solution

  • The warning is about the difference between calling new on a ResultSet object and the ResultSet class name. If you want to create a new ResultSet object using the ResultSet constructor, call new on the ResultSet package:

    my $resultset = DBIx::Class::ResultSet->new(...);

    (Although you typically don't have to create ResultSet objects this way.) If you call new on a ResultSet object, you won't get a new ResultSet object but a corresponding result (row) object:

    my $row = $resultset->new(...);

    Many other Perl classes make no difference whether new is called on the class name or an object of the class, hence the warning.