PostgreSQL schema import that contains a DEFAULT field value made up of functions

Hi!

During the import of an SQL statement which was created from a pg_dump I ran into an issue default values that contain functions like this:

```sql
CREATE TABLE public.person (
id bigint NOT NULL,
(...)
external_id character varying(255) DEFAULT "substring"(md5((random())::text), 1, 6),
);
```

As soon as I remove the DEFAULT instruction here, the import works fine.
This is a very nieche problem, so I just wanted to raise awareness here :)