to set default engine in mysql

Mysql's default engine is not set for foreign key constraints which really bugs me out. So I was looking for a trick to set the default engine to innodb and I finally got this worked.

The default storage engine can be changed at server startup or at runtime:

• The default storage engine can be specified at server startup with the --default-storage-engine option.
• For a running server, an administrator who has the SUPER privilege can change the default storage engine globally for all clients by setting the global storage_engine system variable:
  
  
  

  SET GLOBAL storage_engine = engine_name;

  Setting the storage engine this way affects any client that connects after the statement executes. Clients that are connected at the time of statement execution are unaffected.
• Any client can change its own default storage engine by issuing either of these statements:
  
  

  SET SESSION storage_engine = engine_name;
  SET storage_engine = engine_name;

  ps: I wrote "innodb" instead of "engine_name" 

  this will only change the default engine for temporary. If you would like to set it permanently 

  you should edit the /etc/mysql/my.cnf file.

  
  Then under the [mysqld] add the following line as shown below! [mysqld] default-storage_engine = innodb ...
  
  Finally, restart mySQL;
  $ sudo service mysql restart