Find det seneste dubletter-ID med MySQL

Nå, du svarer sådan set på dit spørgsmål. Du ser ud til at have max(id) :

SELECT email, COUNT(email) AS occurences, max(id)
FROM wineries
GROUP BY email
HAVING (COUNT(email) > 1);

Du kan slette de andre ved hjælp af erklæringen. Slet med join har en vanskelig syntaks, hvor du først skal angive tabelnavnet og derefter angive from klausul med joinforbindelsen:

delete wineries
            from wineries join
            (select email, max(id) as maxid
             from wineries
             group by email
             having count(*) > 1
            ) we
            on we.email = wineries.email and
               wineries.id < we.maxid;

Eller skrive dette som en exists klausul:

delete from wineries
    where exists (select 1
                  from (select email, max(id) as maxid
                        from wineries
                        group by email
                       ) we
                  where we.email = wineries.email and wineries.id < we.maxid
                 )