Unknown database type enum requested ...

Installing the FOSuser and get error after the below step command :

php app/console doctrine:schema:update --force


[Doctrine\DBAL\DBALException]                                               
  Unknown database type enum requested, Doctrine\DBAL\Platforms\MySqlPlatform 
   may not support it.


doctrine:schema:update [--complete] [--dump-sql] [--force] [--em[="..."]]


vi app/config/config.app

add :

mapping_types:
    enum: string

to the doctrine:dbal:

like this : 

doctrine:
    dbal:
        driver: %database_driver%
         host: %database_host%
         port: %database_port%
         dbname: %database_name%
         user: %database_user%
         password: %database_password%
         charset: UTF8
         mapping_types:
             enum: string