The name of the enum the column's values belong to, or null. An enum
outside the connection's default schema is named <schema>.<name>.
Whether an insert may leave the column out: it has a default, or the database generates its values.
The column's name, e.g. created_at.
The type of one of the column's values in types/db.ts, or 'enum'
when the values are those of enumName.
The column's database type as Dream's schema records it, e.g.
bigint,timestamp without time zone[], or an enum's name.