思路
先查询出满足某种条件的数据的最小ID,然后删除最小ID以外的数据就实现了去重
实例
查询最小ID的重复数据
select * from oms_relation_model orm 
where orm.fd_id=
    (
        select min(t.fd_id) from oms_relation_model t 
            where orm.fd_ekp_id=t.fd_ekp_id and orm.fd_ekp_id=t.fd_ekp_id
    )
;
删除操作
delete from oms_relation_model s 
where s.fd_id not in (
    select orm.fd_id from oms_relation_model orm 
    where orm.fd_id=
        (
            select min(t.fd_id) from oms_relation_model t 
            where orm.fd_ekp_id=t.fd_ekp_id and orm.fd_ekp_id=t.fd_ekp_id
        )
);