hibernate多个many-to-many映射时，报错“未明确定义的列”

select * from ( select this_.id as id0_2_, this_.ABSTRACT as ABSTRACT0_2_, this_.author as author0_2_, this_.CREATE_TIME as CREATE4_0_2_, this_.PUB_TIME as PUB5_0_2_, this_.source as source0_2_, this_.title as title0_2_, this_.uuid as uuid0_2_, categories4_.ARTICLE_ID as ARTICLE1_, cs1_.id as CATEGORY2_, cs1_.id as id2_0_, cs1_.CREATE_TIME as CREATE2_2_0_, cs1_.descn as descn2_0_, cs1_.name as name2_0_, cs1_.PARENT_ID as PARENT5_2_0_, cs1_.uuid as uuid2_0_, keywords6_.ARTICLE_ID as ARTICLE1_, kw2_.id as KEYWORD2_, kw2_.id as id5_1_, kw2_.CREATE_TIME as CREATE2_5_1_, kw2_.name as name5_1_ from ARTICLES this_ inner join ARTICLE_CATEGORY categories4_ on this_.id=categories4_.ARTICLE_ID inner join CATEGORYS cs1_ on categories4_.CATEGORY_ID=cs1_.id inner join ARTICLE_KEYWORD keywords6_ on this_.id=keywords6_.ARTICLE_ID inner join KEYWORDS kw2_ on keywords6_.KEYWORD_ID=kw2_.id where cs1_.id=3 and kw2_.name in ('西班牙') order by this_.id desc ) where rownum <= 20

为什么会给取两个一样的别名？