django-haystack in alphabetically in order_by
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I have some problem with ordering in django-haystack >.<

the situation is:
i have Product model,
the product model have company_name attribute and this attribute also included in solr-haystack.

    product_1.company name = "Cba ltd"
    product_2.company_name = "Abc ltd"
    product_3.company_name = "bac ltd"
    product_4.company_name = "aac ltd"

    sqs = SearchQuerySet().models(Product).order_by("company_name")

when i searching and ordering by company name, the result is [product_2, product_1, product_4, product_3]

the system ordering uppercase first then after uppercase finish, will continue to lowercase.

how to make it only alphabetic without checking uppercase or lowercase?
the result supposed to be [product_4, product_2, product_3, product_1]

thank you for helping me in this situation.

cheers,