{"-- Check if updated_at column exists and add it if missing
DO $$ 
BEGIN
    IF NOT EXISTS (
        SELECT 1 
        FROM information_schema.columns 
        WHERE table_name = 'cameras' 
        AND column_name = 'updated_at'
        AND table_schema = 'public'
    ) THEN
        ALTER TABLE public.cameras 
        ADD COLUMN updated_at timestamp with time zone DEFAULT now();
    END IF;
END $$"}