Another note : 95% of work of a data scientist are with SQL. Not R. Rather R is for those that don't know SQL.
Like how NoSQL was the new trend at one time until it was shown that it's no better than SQL in anyway other than "I don't know SQL".
You can create great report, summery and graphs using SQL directly on the database instead of export, convert, load and stuff.
Know the fundamentals. The rest are easy.