Sql 选择每年的最大日期

我的表格如下：

user_id  date
1        2020-11-15
1        2020-10-15
1        2020-09-15
1        2019-12-15
1        2019-11-15
2        2020-11-15
2        2020-10-15
2        2019-12-15
3        2020-10-15
3        2020-09-15

Select t.*
  From your_table t
 Where not exists (select 1 from your_table tt 
                    Where t.id = tt.id
                      And date_trunc('year', t.date) = date_trunc('year', tt.date)
                      And tt.date > t.date)

Select * from
(Select t.*,
       Row_number() over (partition by t.id, date_trunc('year', t.date) 
                          order by t.date desc) as rn
  From your_table t) t
Where rn = 1

我想为每个用户选择每年的最大日期，因此结果如下：

user_id  date
1        2020-11-15
1        2019-12-15
2        2020-11-15
2        2019-12-15
3        2020-10-15

要帮忙吗？ 谢谢大家!

只需使用聚合：

select user_id, max(date)
from t
group by user_id, date_trunc('year', date);

如果您需要更多的列，请在上使用

distinct：

select distinct on (user_id, date_trunc('year', date)) t.*
from t
order by user_id, date_trunc('year', date), date desc;

您可以使用
不存在
，如下所示：

user_id  date
1        2020-11-15
1        2020-10-15
1        2020-09-15
1        2019-12-15
1        2019-11-15
2        2020-11-15
2        2020-10-15
2        2019-12-15
3        2020-10-15
3        2020-09-15

Select t.*
  From your_table t
 Where not exists (select 1 from your_table tt 
                    Where t.id = tt.id
                      And date_trunc('year', t.date) = date_trunc('year', tt.date)
                      And tt.date > t.date)

Select * from
(Select t.*,
       Row_number() over (partition by t.id, date_trunc('year', t.date) 
                          order by t.date desc) as rn
  From your_table t) t
Where rn = 1

或者您可以使用
行号
分析功能，如下所示：

user_id  date
1        2020-11-15
1        2020-10-15
1        2020-09-15
1        2019-12-15
1        2019-11-15
2        2020-11-15
2        2020-10-15
2        2019-12-15
3        2020-10-15
3        2020-09-15

Select t.*
  From your_table t
 Where not exists (select 1 from your_table tt 
                    Where t.id = tt.id
                      And date_trunc('year', t.date) = date_trunc('year', tt.date)
                      And tt.date > t.date)

Select * from
(Select t.*,
       Row_number() over (partition by t.id, date_trunc('year', t.date) 
                          order by t.date desc) as rn
  From your_table t) t
Where rn = 1