Mysql compare different rows

December 3, 2021

i have the following table
id | user | date | value. I need to find users that have values on eg October month but they dont have on November month.
I ve tried the following code around.

select *
from users B 
LEFT OUTER JOIN data A 
on A.user = B.user
Where B.permissions=1 AND A.date BETWEEN '2021-11-01' AND '2021-11-30' group by A.user

>Solution :

select *
from users as usr
where permissions = 1
  and exists (     -- have data for october 2021
    select 1
    from data AS d
    where d.user = usr.user
      and d.date BETWEEN '2021-10-01' AND '2021-10-31' 
  )
  and not exists ( -- no data for november 2021
    select 1
    from data AS d
    where d.user = usr.user
      and d.date BETWEEN '2021-11-01' AND '2021-11-30' 
  )