mysql一括更新データはランダムに異なる内容です

UPDATE pool_key_customer SET latitude = CASE (SELECT (CEIL(RAND() * 2) + 2)%2) WHEN 0 THEN (SELECT (RAND()*90)) WHEN 1 THEN (SELECT (RAND()*90))  END,
longitude = CASE (SELECT (CEIL(RAND() * 2) + 2)%2) WHEN 0 THEN (SELECT (RAND()*180)) WHEN 1 THEN (SELECT (RAND()*180))  END