Seneste datetime fra unikt mysql-indeks

Først skal du finde ud af den største dato for hver check

 SELECT `check`, MAX(`datetime`)
 FROM YourTable
 WHERE `service` = 2
 GROUP BY `check`

Tilmeld dig derefter for at få resten af ​​dataene.

 SELECT Y.*
 FROM YourTable Y
 JOIN ( SELECT `check`, MAX(`datetime`) as m_date
        FROM YourTable
        WHERE `service` = 2
        GROUP BY check) as `filter`
  ON Y.`service` = `filter`.service
 AND Y.`datetime` = `fiter`.m_date
 WHERE Y.`service` = 2