You need to use the Create Database Wizard to create a database to use with EF entity classes.

Which definition do you need to create in order to use the Create Database Wizard?

The Create Database Wizard requires a valid conceptual model (CSDL) to run successfully. Note that the wizard does not require a valid .edmx file. Only the CSDL content of the .edmx file must be valid.

DDL is used to define and manage all the objects in an SQL database. The Create Database Wizard provides an alternative to writing complex DDL statements and does not require its usage.

Upon completion, the Create Database Wizard generates the SSDL and MSL that correspond to the provided CSDL. The .edmx file is updated with the generated SSDL and MSL. You do not need to create the SSDL.