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您好，我正在尝试在 GIN 索引列上使用 postgresql/FTS 在 Django 上进行搜索，但出现了一个奇怪的错误。此错误不会出现在 CharField 上，而只会出现在 SearchVectorField 上：

Postgresql 数据库安装了 pg_trgm 扩展（在 Django 迁移中）

这是对象：

class Language(models.Model):
    code = models.CharField(primary_key=True, max_length=5, verbose_name=_("code"))
    label = models.CharField(max_length=50, verbose_name=_("label"))
    search = SearchVectorField(null=True)

    objects = Language_Manager()

    class Meta:
        verbose_name = _("language")
        verbose_name_plural = _("languages")
        indexes = [
            GinIndex(fields=["search"], name="search_index",),
        ]

    def save(self):
        fields = [x for x in dir(self) if x[:5] == "label"]
        labels = [getattr(self, field) for field in fields if getattr(self, field)]
        self.search = self.search + " ".join(labels)
        super().save()

这是我的查询：

from core.models import Language as LanguageCode
from django.contrib.postgres.search import TrigramSimilarity

LanguageCode.objects.all().annotate(sim=TrigramSimilarity("search", "english"))

它返回一条错误消息：

LINE 1: ...e_language"."label_ko", "core_language"."search", SIMILARITY...
                                                            ^
HINT:  No function matches the given name and argument types. You might need to add explicit type casts.

如果我使用标准CharField而不是 GIN 索引SearchVectorField，则不会发生错误：

from core.models import Language as LanguageCode
from django.contrib.postgres.search import TrigramSimilarity

LanguageCode.objects.all().annotate(sim=TrigramSimilarity("label", "english"))

<MultilingualQuerySet [<Language: Language object (fr)>, <Language: Language object (en)>, >><Language: Language object (it)>, ...

难道我做错了什么 ？

我也在使用 Django-model-translation 和这个对象的标签列：

from modeltranslation.translator import translator, TranslationOptions
from core.models import Language

class LanguageTranslationOptions(TranslationOptions):
    fields = ("label",)

translator.register(Language, LanguageTranslationOptions)
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