Function queue_enum_type_ddl 

pub fn queue_enum_type_ddl(name: &str, members: &[&str]) -> DuckResult<()>

queue_enum_type_ddl_with 的默认形式：排队一条 CREATE TYPE IF NOT EXISTS ...。

The default flavour of queue_enum_type_ddl_with: queues a CREATE TYPE IF NOT EXISTS ... statement.

#[duck_custom_register]
fn queue_my_types(_connection: &Connection) -> DuckResult<()> {
    duckfn::queue_enum_type_ddl("color", &["red", "green", "blue"])
}