MySQL Select Last Entry for each User, than the next entry

Question

i have 2 tables, one for users (recruiters) and the other for CV

CREATE TABLE users (
    id int primary,
    email string,
    company string
)
CREATE TABLE cv (
    id int primary,
    title string,
    user_id int,
    created_date datetime
)

The user can post many CV .

So what i want is to select the last CV from each user ordred by created_date than the next cv and so on...

the result would be like this:

the list of CV is ordred by created_date DESC

• the last CV posted by user_1
• the last CV posted by user_2
• the last CV posted by user_3
• the last CV posted by user_...
• ....
• the next CV posted by user_1
• the next CV posted by user_2
• the next CV posted by user_3
• the next CV posted by user_...
• ....

what i want is one entry (the last) for each user, than the next entry for each user:

last Entry for user 1
last entry for user 2
last entry for user 3
last entry for user 4
....and so on...than
the entry before the last (because entries are ordred by date desc) for user 1
the entry before the last for user 2
the entry before the last for user 3
...and so on...

i have found this solution by it doesn't work

SELECT IF(@prev != a.`company_name`, @rownum:=1, @rownum:=@rownum+1) 
as rownumber, @prev:=a.`company_name`, a.* FROM 
(SELECT `cv`.`id` AS `id` , `cv`.`company_name` FROM `cv` , 
(SELECT @rownum := 0, @prev:='') sq ORDER BY `created_date` DESC) a order by rownumber

Answer 1

The correct version for your problem is:

select cv.*
from (select cv.*,
             (@rn := if(@c = company_name, @rn + 1,
                        if(@c := company_name, 1, 1)
                       )
             ) as rn
      from cv cross join
           (select @c := '', @rn := 0) vars
      order by company_name, created_date desc
     ) cv
order by rn, user_id;

You want to put all the variable assignments in a single expression, because MySQL does not guarantee the order of evaluation of expressions in a select . You can join in additional information from other tables.

Answer 2

i found this solution, and it seems to work:

    SELECT IF(@prev != a.`user_id`, @rownum:=1, @rownum:=@rownum+1) as rownumber, 
@prev:=a.`user_id`, a.* FROM (SELECT `cv`.`id` AS `id` , `cv`.`company_name` , 
cv.created_date, `cv`.`user_sid` FROM `cv` , (SELECT @rownum := 0, @prev:='') sq 
{WHERE CLAUSE} ORDER BY `cv`.`user_id` ASC, `cv`.`created_date` DESC) a order by rownumber, 
created_date desc;

if you have a where clause you can put it in the {WHERE CLAUSE}