SQL 查询具有最后结束日期的非活动用户

Question

This is a follow up from a question I asked about a year ago Old thread The answers I got then have worked fine but now I discovered that I need to tweak the query to be able to get the latest end date for the inactive users.

So again here's a quick example table of users, some are active and some are inactive and some have several period of employment.

when someone is reemployed a new row will be added for that employment period. Username will always be the same.

So I want to find which users that is disabled and doesn't have an active employment also if there is several period of employment I want the one that has the latest end date. One row per username with all the columns.

The database is SQL Server 2016.

Example table:

|  username | name       | active | Job title   | enddate 
+-----------+----------- +--------+-------------+----------
| 1111      | Jane Doe   |    1   | CIO         | 1/3/2022
| 1111      | Jane Doe   |    0   | Janitor     | 1/2/2018
| 1112      | Bob Doe    |    1   | Coder       | NULL
| 1113      | James Doe  |    0   | Coder       | 1/3/2018
| 1114      | Ray Doe    |    1   | Manager     | NULL
| 1114      | Ray Doe    |    0   | Clerk       | 2/2/2019
| 1115      | Emma Doe   |    1   | Waiter      | NULL
| 1116      | Sarah Doe  |    0   | Greeter     | 3/4/2016
| 1116      | Sarah Doe  |    0   | Trainer     | 4/5/2019

So for user 1116 I would ideally get one row with enddate 4/5/2019

The query I use from the answers in the old thread is this one:

    ;WITH NonActiveDisabledUsers AS
(
    SELECT DISTINCT
        U.username
    FROM
        UserEmployment AS U
    WHERE
        U.active = 0 AND
        NOT EXISTS (SELECT 'no current active employment' 
                    FROM UserEmployment AS C
                    WHERE U.username = C.username AND 
                    C.active = 1 AND
                    (C.enddate IS NULL OR C.enddate >= CONVERT(DATE, GETDATE())))
)
SELECT
    R.*
FROM
    NonActiveDisabledUsers AS N
    CROSS APPLY (
        SELECT TOP 1        -- Just 1 record
            U.*
        FROM
            UserEmployment AS U
        WHERE
            N.username = U.username AND
            U.active = 0
        ORDER BY
            U.enddate DESC  -- Determine which record should we display
        ) AS R

This gives me the right user and employment status but not the latest end date since it will get the first result for user 1116

Answer 1

We can use conditional aggregation with a window aggregate to get the number of active rows for this user.

We then filter to only inactive, and row-number the result by enddate taking the first row per group:

SELECT
    username,
    name,
    active,
    [Job title],
    enddate 
FROM (
    SELECT *, rn = ROW_NUMBER() OVER (PARTITION BY username ORDER BY enddate DESC)
    FROM (
        SELECT *,
          CountOfActive = COUNT(CASE WHEN
                Active = 1 AND
                (enddate IS NULL OR enddate >= CONVERT(DATE, GETDATE())) THEN 1 END
              ) OVER (PARTITION BY username)
        FROM UserEmployment
    ) AS t
    WHERE CountOfActive = 0
) AS t
WHERE rn = 1;

Note that the row-numbering does not take into account nulls in enddate which would be sorted last. You would need a conditional ordering:

ROW_NUMBER() OVER (PARTITION BY username ORDER BY CASE WHEN enddate IS NULL THEN 0 ELSE 1 END ASC, enddate DESC)

Answer 2

Hmmm. . . I think you can just get the most recent record and check that it is not active:

select ue.*
from (select ue.*,
             row_number() over (partition by user_id
                                order by active desc, enddate desc
                               ) as seqnum
      from UserEmployment ue
     ) ue
where seqnum = 1 and active = 0;

Answer 3

Here is a variant that will produce the desired result:

 SELECT distinct username, max(enddate)  
  FROM UserEmployment as t1
  WHERE
    t1.active = 0 AND 
    NOT EXISTS (select username from UserEmployment as t2 WHERE active = 1 AND
                    (t2.enddate IS NULL OR t2.enddate >= CONVERT(DATE, GETDATE())) AND
                     t1.username = t2.username)
  GROUP BY username