SQL Server: does ddladmin rights contain datareader and datawriter rights to the database? Does db_ddladmin fixed database role include db_datareader and db_datawriter rights, so that you don't have to grant those rights explicitly?
I don't believe so. It should only allow them to run DDL not access tables.

You could make your own role and make it be a member of the db_ddladmin, db_datareader and db_datawriter roles.