我想改变搜索排名与三角相似性，但我得到了这个错误
/search/ function similarity（character varying，unknown）does not exist行1：...ows_show”.“description”，''）），'B'））AS“search”，SIMILARITY...^提示：没有函数匹配给定的名称和参数类型。您可能需要添加显式类型强制转换。
我的代码：

def search_content(query: str) -> QuerySet | None:

if query:
    search_vector = SearchVector("name", weight="A") + SearchVector("description", weight="B")

    shows = (
        Show.objects.annotate(
            search=search_vector, similarity=TrigramSimilarity('name', query),
        )
        .filter(similarity__gt=0.4)
        .values("id", "name", "baner", "release_date", "search", "similarity")
    )
    
    movies = (
        Movie.objects.annotate(
            search=search_vector, similarity=TrigramSimilarity('name', query),
        )
        .filter(similarity__gt=0.4)
        .values("id", "name", "baner", "release_date", "search", "similarity")
    )
    
    episodes = (
        Episode.objects.annotate(
            search=search_vector, similarity=TrigramSimilarity('name', query),
        )
        .filter(similarity__gt=0.4)
        .values("id", "name", "baner", "release_date", "search", "similarity")
    )

    qs = shows.union(movies, episodes).order_by("-similarity")

    return qs

else:
    return None