note zwon <p>I see that [mod://DBIx::Class::Schema::Loader::DBI::mysql] uses <c>SHOW CREATE TABLE</c> to get table definition, and then looking for <c> CONSTRAINT ... FOREIGN KEY ... REFERENCES ... </c> to get information about foreign keys. I tried to create some tables in mysql and check the output of <c>SHOW CREATE TABLES</c>: <c> mysql> create table foo (id integer primary key, name varchar(10)); Query OK, 0 rows affected (0.01 sec) mysql> create table boo (id integer primary key, foo_id integer references foo(id)); Query OK, 0 rows affected (0.00 sec) mysql> create table bar (id integer primary key, foo_id integer, constraint foo_id_fk foreign key (foo_id) references foo(id)); Query OK, 0 rows affected (0.00 sec) mysql> show create table boo; +-------+--------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+--------------------------------------------------------------------------------------------------------------------------------------------+ | boo | CREATE TABLE `boo` ( `id` int(11) NOT NULL, `foo_id` int(11) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+--------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) mysql> show create table bar; +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table | +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | bar | CREATE TABLE `bar` ( `id` int(11) NOT NULL, `foo_id` int(11) DEFAULT NULL, PRIMARY KEY (`id`), KEY `foo_id_fk` (`foo_id`), CONSTRAINT `foo_id_fk` FOREIGN KEY (`foo_id`) REFERENCES `foo` (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 | +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec) mysql> drop table foo; ERROR 1217 (23000): Cannot delete or update a parent row: a foreign key constraint fails mysql> drop table bar; Query OK, 0 rows affected (0.00 sec) mysql> drop table foo; Query OK, 0 rows affected (0.00 sec) </c> <p>As you can see, it looks like mysql silently ignores <c>references</c> in your SQL statements and doesn't create foreign keys. I would say it is rather nasty behaviour, if it doesn't accept your syntax it should throw an error. 1012551 1013220