这是创建新列并保留旧日期时间的最简单方法?使用格式?
来自日期时间列“2018-05-15 09:45:00.000”的结果如 201805、201806 或 1805、1806 等
您可以添加计算列。例子:
Run Code Online (Sandbox Code Playgroud)create table docs ( doc_id int not null primary key, dt datetime not null ) ;
?
Run Code Online (Sandbox Code Playgroud)insert into docs (doc_id, dt) values (1, '2000-01-01 00:00:00'), (2, '2001-05-12 12:30:00'), (3, '2007-07-07 16:45:00'), (4, '2018-01-01 12:00:00'), (5, '2018-05-15 15:50:00') ;
5 行受影响
Run Code Online (Sandbox Code Playgroud)select * from docs;
doc_id | dt -----: | :------------------ 1 | 01/01/2000 00:00:00 2 | 12/05/2001 12:30:00 3 | 07/07/2007 16:45:00 4 | 01/01/2018 12:00:00 5 | 15/05/2018 15:50:00
Run Code Online (Sandbox Code Playgroud)alter table docs add year_month as year(dt) * 100 + month(dt) ;
Run Code Online (Sandbox Code Playgroud)select * from docs;
doc_id | dt | 年_月 -----: | :------------------ | ---------: 1 | 01/01/2000 00:00:00 | 200001 2 | 12/05/2001 12:30:00 | 200105 3 | 07/07/2007 16:45:00 | 200707 4 | 01/01/2018 12:00:00 | 201801 5 | 15/05/2018 15:50:00 | 201805
db<>在这里摆弄