题解 | #查询用户刷题日期和下一次刷题日期#

select 
    user_id,
    date,
    LEAD(date,1) over(partition by user_id order by date) as nextdate
from questions_pass_record
order by user_id



#FIRST_VALUE()： 获取分组内指定列的第一个值。
#FIRST_VALUE(column) OVER (PARTITION BY column ORDER BY column)
#LAST_VALUE()： 获取分组内指定列的最后一个值。
#LAST_VALUE(column) OVER (PARTITION BY column ORDER BY column)
# LEAD()： 获取指定列在当前行之后的值。
#LEAD(column, n) OVER (PARTITION BY column ORDER BY column)
# LAG()： 获取指定列在当前行之前的值。
#LAG(column, n) OVER (PARTITION BY column ORDER BY column)