Mybatis sql has the problem that the return value of the query is object type

The original sql is written like this 

select * from 

(select e.keyid,e.trade_sub_id,e.product_id,e.product_name,a.owenauth_userid from 

<!-- e --> (select id as keyid,trade_sub_id,product_id,product_name from ente_product where sysdate() between start_date and end_date  and ente_id=#{ente_id} ) e 

<!-- a --> left join (select ifnull(owenauth_userid,'') as owenauth_userid,trade_sub_id from ent_total_authno where isauth='1' and sysdate() between auth_start_date and auth_end_date

and owenauth_userid=#{owenauth_userid}

) a 

<!-- pro --> on e.trade_sub_id=a.trade_sub_id group by e.keyid) pro 

left join 

<!-- goo -->(select distinct g.id as gid,g.inurl,ifnull(p.mainpicurl,'') as mainpicurl from goods_mainpic p right join goods g on g.id=p.goodsid group by g.id) goo 

on goo.gid=pro.product_id

In the returned value, owenauth_userid is of object type and the value is incorrect. Later, change the red color to owenauth_userid to get a normal value. The reason is that owenauth_userid is of bigint type in the database, so it should be written as ifnull( owenauth_userid  ,0 ) as  owenauth_userid