--删除表中多余的重复记录，重复记录是根据单个字段（ChangCiId）来判断，只留有Id最大的记录
delete from tb_FootballMatch
where ChangCiId in (select  ChangCiId from tb_FootballMatch group by   ChangCiId   having count
(ChangCiId) > 1)
and Id not in (select max(Id) from   tb_FootballMatch group by ChangCiId having count(ChangCiId
)>1)

SQL删除重复记录