Is necessary to create an explicit relation in the data base after defining it in the Sails js' model?

I created a model with their respective relation using the following approach

http://sailsjs.com/documentation/concepts/models-and-orm/associations

and everything seems to be OK. But, when i open the model's tables which SailsJs created, in Mysql workbench. There isn't any relation between tables. So; do i need to specify the relations or leave the tables as they are and continue working with the relations that exists on SailsJs?

via superkiller170793