Re: Identifying Foreign Key constraints

[Brian McNamara]

Hi Michael,

Foreign keys are not available on ISAM/MyISAM table types. They are only available on InnoDB tables in MySQL Server 3.23.44 and higher. If you used foreign key constraints in your definition in a MyISAM table it would not generate errors but it wouldn't create the constraint.

To verify in a nice format, run the following command:

mysql> use DATABASE;

mysql> show table status like 'TABLENAME';

This should show you important features like table type and create options. If it's MyISAM/ISAM, you'll see it in "Type." If it is an InnoDB table and there are foreign key constraints, you'll see them in the "Comment" field.

Hope this helps!
Brian