写一条可以执行的SQL: 表名t_subiect_score，包含字段st_id(学生ID)，si_id(学科ID)，si_score(学科得分);请列出综合成绩前三名的学生ID及总分，写出SQL

SELECT st_id, SUM(si_score) AS total_score
FROM t_subiect_score
GROUP BY st_id
ORDER BY total_score DESC
LIMIT 3;