MySQL Error 1215: Cannot add foreign key constraint

Question

I am trying to forward engineer my new schema onto my db server, but I can\'t figure out why I am getting this error. I\'ve tried to search for the answer here, but everyth

Answer 1

There is a pitfall I have experienced with "Error 1215: Cannot add foreign key constraint" when using Laravel 4, especially with JeffreyWay's Laravel 4 Generators.

In Laravel 4, you can use JeffreyWay's Generators to generate migration files to create tables one-by-one, which means, each migration file generates one table. You have to be aware of the fact that each migration file is generated with a timestamp in the filename, which gives the files an order. The order of generation is also the order of migration operation when you fire the Artisan CLI command "php artisan migrate". So, if a file asks for a foreign key constraint referring to a key which will be, but not yet, generated in a latter file, the Error 1215 is fired. In such case, what you have to do is adjust the order of migration files generation. Generate new files in proper order, copy-in the content, then delete the disordered old files.