You can't specify target table 'Person' for update in FROM clause

DELETE FROM Person WHERE Id NOT IN (
　　 --mysql不能先select出同一表中的某些值，再update这个表(在同一语句中)
    SELECT MIN(p.Id) AS Id 
    FROM Person p 
    GROUP BY p.Email  
)  ;

DELETE FROM Person WHERE Id NOT IN (
    --把临时表再select以下就好了
    SELECT Id FROM (
            SELECT MIN(p.Id) AS Id 
            FROM Person p 
            GROUP BY p.Email) temp    
)  ;