从我的sql中的datekey中提取年和月

Question

I have a datekey column in my database. I want to extract Year and Month from it.

Datekey column
20140101
20151223
20140809
20201201

Answer 1

Assuming these are numbers, use numeric operations:

select floor(datekey / 10000) as year,
       (datekey / 100) % 100 as month,
       datekey % 100 as day
        

Answer 2

You can try the below -

select month(convert(datekey,char)) as mon, 
       year(convert(datekey,char)) as yr
from tablename