-- +goose Up
-- Each blog gets its own database; the registry remembers which one.
-- db_name stays nullable until the Go migration 00006 has moved the content.
ALTER TABLE blogs ADD COLUMN db_name text UNIQUE;
-- "blog_" + subdomain must fit in a 63-char Postgres identifier.
ALTER TABLE blogs DROP CONSTRAINT blogs_subdomain_check;
ALTER TABLE blogs ADD CONSTRAINT blogs_subdomain_check CHECK (subdomain ~ '^[a-z0-9](-?[a-z0-9]){0,57}$');

-- +goose Down
ALTER TABLE blogs DROP CONSTRAINT blogs_subdomain_check;
ALTER TABLE blogs ADD CONSTRAINT blogs_subdomain_check CHECK (subdomain ~ '^[a-z0-9](-?[a-z0-9]){0,62}$');
ALTER TABLE blogs DROP COLUMN db_name;