Selezionare ultimo record di una sotto query

SELECT *
FROM (
    SELECT
      d.id             AS d_id
    , d.cognome        AS d_cognome
    , d.nome           AS d_nome
    , d.Cooperative_Id AS d_Cooperative_Id
    , c.id             AS c_id
    , c.cooperativa    AS c_cooperativa
    , a.id             AS a_id
    , a.dipendenti_id  AS a_dipendenti_id
    , a.tipo           AS a_tipo
    , a.dataassunzione AS a_dataassunzione
    , a.datadimissione AS a_datadimissione
    , ( SELECT max(x.dataassunzione) FROM assunzioni x WHERE x.dipendenti_id = d.id ) AS x_dataassunzione
    FROM      dipendenti  d
    LEFT JOIN cooperative c ON d.cooperative_id = c.id
    LEFT JOIN assunzioni  a ON a.dipendenti_id  = d.id
) y
WHERE ( a_dipendenti_id  is null OR ( a_datadimissione is not null AND x_dataassunzione = a_dataassunzione ) )
  AND ( d_cognome LIKE '%%' OR d_nome LIKE '%%' )
  AND d_Cooperative_Id = 1
ORDER BY d_cognome, d_nome "%%") AND d_Cooperative_Id = 1 ORDER BY d_cognome, d_nome

SELECT d.*, a.* FROM dipendenti d 
INNER JOIN assunzioni a ON a.dipendenti_id = d.id
WHERE d.Cooperative_Id = 1 AND a.datadimissione IS NULL GROUP BY d.id ORDER BY Cognome