macro_rules! define_database { ($struct_name: ident, $name: literal) => { ... }; ($struct_name: ident, $name: literal, $migrations: literal) => { ... }; }
macro_rules! define_database { ($struct_name: ident, $name: literal) => { ... }; ($struct_name: ident, $name: literal, $migrations: literal) => { ... }; }