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题解 | #查看不同年龄段的用户明细#

select device_id, gender, #多种情况使用when在case中分别讨论 ( case when age < 20 then '20岁以下' when age between 20 ...

2024-03-03

0 256

题解 | #计算25岁以上和以下的用户数量#

select ( case when age >= 25 then '25岁及以上' else '25岁以下' end ) as age_cut, count(*) as number fr...

2024-03-03

0 205

题解 | #统计每个用户的平均刷题数#

select university, difficult_level, round( count(qpd.device_id) / count(distinct qpd.question_id), 4 ) as avg_answer_c...

2024-03-03

0 253

题解 | #统计每个学校各难度的用户平均刷题数#

select university, difficult_level, #注意distinct qpd.device_id round( count(qpd.question_id) / count(distinct qpd.device_id), ...

2024-03-03

0 206

题解 | #统计每个学校的答过题的用户的平均答题数#

select university, #注意distinct qpd.device_id要指明对qpd或up表中的device_id去重，否则无法明确是哪个device_id round(count(question_id) / count(distinct qpd.device_...

2024-03-03

0 225

题解 | #分组过滤练习题#

select university, round(avg(question_cnt), 3) as avg_question_cnt, round(avg(answer_cnt), 3) as avg_answer_cnt from user_profile grou...

2024-03-03

0 256

题解 | #计算男生人数以及平均GPA#

select count(*) as male_num, round(avg(gpa), 1) as avg_gpa from user_profile where gender = 'male'; #注意round去小数点一位

2024-03-03

0 223

题解 | #查找兄弟单词#

while True: try: data = input().split() # print(data) n = int(data[0]) k = int(data[-1]) key_word = data[-...

2023-12-10

0 255

题解 | #计算某字符出现次数#

import sys strs = input() char = input() count = 0 for str in strs: if char.upper() == str or char.lower() == str: count += 1 print(coun...

2023-12-03

0 235

题解 | #字符串最后一个单词的长度#

import sys str = input() last_char = str.split(' ')[-1] print(len(last_char))

2023-12-03

0 277