sql查询错误#Syntax

Question

Select heros.Nom,heros.Prenom
From (
    SELECT  ID_Heros, 
            COUNT(ID_ville) AS nmbr,
            (
                SELECT * 
                FROM etape 
                RIGHT JOIN participe ON etape.ID_Expedition= pqrticipe.ID_Expedition
            ) as sub1 
    GROUP BY ID_Heros 
    ORDER BY COUNT(ID_ville) LIMIT 1
) As sub2 
INNER JOIN heros On sub2.ID_Heros = heros.ID_Héros

问题： 查询用于：最旅行的英雄（最不同的城市交叉）

1064 - 'GROUP BY ID_Heros ORDER BY COUNT（city_ID）LIMIT 1附近的语法错误as sub2

INNER JOIN hero 'at line 5

为什么我有这个错误？ （我怎么能解决它）

我认为这是2个计数，但我不确定