-- Fix: Allow audio_url to be nullable since tracks can be created before audio is uploaded
ALTER TABLE tracks ALTER COLUMN audio_url DROP NOT NULL;

-- Also make cover_url nullable for the same reason
ALTER TABLE tracks ALTER COLUMN cover_url DROP NOT NULL;

-- Set default empty string for existing null values if needed
UPDATE tracks SET audio_url = '' WHERE audio_url IS NULL;
UPDATE tracks SET cover_url = '' WHERE cover_url IS NULL;