题解 | #实习广场投递简历分析(一)#

SELECT job,
       SUM(num) AS cnt
FROM resume_info
WHERE date BETWEEN '2025-01-01' AND '2026-01-01'
GROUP BY job
ORDER BY cnt DESC
易错点：因为窗口函数 SUM(num) OVER (PARTITION BY job) 为每个 job 的每行计算了总和，并且没有进行分组。
代码返回每个 job 的每行记录，每行都显示该 job 的总 num 值。即，如图