Foreign key relationship methods deferred and never created in RDBO - mysql

Question

I'm playing with RoseDB::Object on the employees test dataset, and for some reason, I can't get my foreign key relationships ('department' and 'employee') to work on the DeptEmp object. (Class structure below).
When I try $e->dept_emp->[0]->department, I get:
Can't locate object method "department" via package "My::FakeEmployees::DeptEmp"
Methods for the following relationships and foreign keys were deferred and
then never actually created in the class My::FakeEmployees::DeptEmp.
TYPE NAME
---- ----
Foreign Key department
Foreign Key employee
I'm sure I have something set up wrong in my class structure, but what?
CLASS STRUCTURE (some classes omitted for clarity):
I created the various objects using the instructions in the RDBO tutorial:
package My::FakeEmployees::Employee;
use strict;
use base qw(My::FakeEmployees::DB::Object);
__PACKAGE__->meta->setup(
table => 'employees',
columns => [
emp_no => { type => 'serial', not_null => 1 },
birth_date => { type => 'date', not_null => 1 },
first_name => { type => 'varchar', length => 14, not_null => 1 },
last_name => { type => 'varchar', length => 16, not_null => 1 },
gender => { type => 'enum', check_in => [ 'M', 'F' ], not_null => 1 },
hire_date => { type => 'date', not_null => 1 },
],
primary_key_columns => ['emp_no'],
'relationships' => [
'departments' => {
'type' => 'many to many',
'map_class' => 'My::FakeEmployees::DeptEmp',
},
'dept_emp' => {
'type' => 'one to many',
'class' => 'My::FakeEmployees::DeptEmp',
'column_map' => { 'emp_no' => 'emp_no' },
},
'dept_manager' => {
'type' => 'one to many',
'class' => 'My::FakeEmployees::DeptManager',
'column_map' => { 'emp_no' => 'emp_no' },
},
'salaries' => {
'type' => 'one to many',
'class' => 'My::FakeEmployees::Salary',
'column_map' => { 'emp_no' => 'emp_no' },
},
'titles' => {
'type' => 'one to many',
'class' => 'My::FakeEmployees::Title',
'column_map' => { 'emp_no' => 'emp_no' },
},
],
);
__PACKAGE__->meta->make_manager_class('employees');
1;
package My::FakeEmployees::DeptEmp;
use strict;
use base qw(My::FakeEmployees::DB::Object);
__PACKAGE__->meta->setup(
table => 'dept_emp',
columns => [
dept_no => { type => 'character', not_null => 1 },
emp_no => { type => 'integer', not_null => 1 },
from_date => { type => 'date' },
to_date => { type => 'date' },
],
primary_key_columns => [ 'emp_no', 'dept_no' ],
foreign_keys => [
department => {
class => 'My::FakeEmployees::Departments',
key_columns => { dept_no => 'dept_no' },
},
employee => {
class => 'My::FakeEmployees::Employees',
key_columns => { emp_no => 'emp_no' },
},
],
);
__PACKAGE__->meta->make_manager_class('dept_emp');
1;
package My::FakeEmployees::Department;
use strict;
use base qw(My::FakeEmployees::DB::Object);
__PACKAGE__->meta->setup(
table => 'departments',
columns => [
dept_no => { type => 'character', length => 4, not_null => 1 },
dept_name => { type => 'varchar', length => 40, not_null => 1 },
],
primary_key_columns => ['dept_no'],
unique_key => ['dept_name'],
'relationships' => [
'employees' => {
'type' => 'many to many',
'map_class' => 'My::FakeEmployees::DeptEmp',
},
],
);
__PACKAGE__->meta->make_manager_class('departments');
1;

Answer 1

Your foreign key has a typo:
foreign_keys => [
department => {
class => 'My::FakeEmployees::Departments',
That should be 'Department', not 'Departments'

Answer 2

It turned out to be a mistake in my code. These lines in DeptEmp.pm:
foreign_keys => [
department => {
class => 'My::FakeEmployees::Departments',
key_columns => { dept_no => 'dept_no' },
},
employee => {
class => 'My::FakeEmployees::Employees',
key_columns => { emp_no => 'emp_no' },
},
],
Have incorrect class names. It should be My::FakeEmployees::Employee and My::FakeEmployees::Department. Singular, not plural.