MySQL 8.0

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select version();


version()


8.0.30


create table t
(iD	int auto_increment primary key, dt date);

insert into t (dt) values
('2023-01-01'),('2023-01-01'),
('2023-02-01'),
('2023-03-01'),('2023-03-02'),('2023-03-03')
;
create table t1
with cte as
(
select distinct cast(date_format(t.dt,'%Y%m') as unsigned)ym
from t)
select * from cte
join t on cast(date_format(t.dt,'%Y%m') as unsigned) <= cte.ym ;


Records: 6  Duplicates: 0  Warnings: 0



Records: 11  Duplicates: 0  Warnings: 0


select * from t1;


ym
iD
dt


202301
2
2023-01-01

202301
1
2023-01-01

202302
3
2023-02-01

202302
2
2023-01-01

202302
1
2023-01-01

202303
6
2023-03-03

202303
5
2023-03-02

202303
4
2023-03-01

202303
3
2023-02-01

202303
2
2023-01-01

202303
1
2023-01-01


show create table t1;


Table
Create Table


t1
CREATE TABLE `t1` (
  `ym` bigint unsigned DEFAULT NULL,
  `iD` int NOT NULL DEFAULT '0',
  `dt` date DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci

ym	iD	dt
202301	2	2023-01-01
202301	1	2023-01-01
202302	3	2023-02-01
202302	2	2023-01-01
202302	1	2023-01-01
202303	6	2023-03-03
202303	5	2023-03-02
202303	4	2023-03-01
202303	3	2023-02-01
202303	2	2023-01-01
202303	1	2023-01-01