SQL17、计算男生人数以及平均gpa

思路：使用WHERE关键字添加限定条件，用 COUNT关键字计算人数，用AVG关键字计算平均值

代码解释：限定数据来自性别为难的记录，然后计算人数以及gpa均值

SELECT 
  COUNT(gender) AS male_num,
  AVG(gpa) AS avg_gpa
FROM 
  user_profile
WHERE 
  gender = 'male'

题目：https://www.nowcoder.com/practice/7d9a7b2d6b4241dbb5e5066d7549ca01?tpId=199&tags=&title=&difficulty=0&judgeStatus=0&rp=0&sourceUrl=%2Fexam%2Foj%3Fpage%3D1%26tab%3DSQL%25E7%25AF%2587%26topicId%3D199