-- The keys cannot be recovered from their hashes. Rolling back gives every
-- user a new random key; Subsonic clients using apiKey need the new one.
ALTER TABLE users ADD COLUMN api_token text;
UPDATE users SET api_token = md5(random()::text || id::text || clock_timestamp()::text);
ALTER TABLE users ALTER COLUMN api_token SET NOT NULL;
ALTER TABLE users ADD CONSTRAINT users_api_token_key UNIQUE (api_token);
ALTER TABLE users DROP COLUMN api_token_hash;