access denied for user "@'localhost for database 'db_name'

I installed MySQL with package installer on Mac OS x, then I ran query browser and connected to database with username = "" and password = "". Now, I want to create a new sc开发者_Go百科hema, when a type create schema rest, it shows an error like access denied for user "@'localhost' to database 'rest'

how can i fix this?

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Try logging in with username "root" and password "".