You can't set precision and scale via console. You have to mention these attributes when you declare fields, either in ORM YAML file, as annotation, etc.
To see how to set precision and scale in annotation, here is the link,
http://docs.doctrine-project.org/en/2.0.x/reference/annotations-reference.html#column
You can see all available doctrine 2 data types in here,
http://doctrine-dbal.readthedocs.org/en/latest/reference/types.html
For Decimal precision and scale you can see it in here,
http://doctrine-dbal.readthedocs.org/en/latest/reference/types.html#id89
Hope this helps, Cheers!