Django：將兩個查詢合二為一

Question

我目前很難將query_1和query_2組合成一個query_combined 。 你知道如何實現這一目標嗎？

query_1 = (
    Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT,
        answers__question__focus=QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN,
    ).filter(answers__answer="Very disappointed")
)

query_2 = (
    Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT,
        answers__question__focus=QuestionFocus.RECOMMENDATION_TO_FRIENDS,
    )
    .annotate(answer_num=Cast("answers__answer", IntegerField()))
    .filter(answer_num__gt=8)
)

這是解決方案：

combined_query = (
    Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT,
        answers__question__focus__in=[
           QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN,
           QuestionFocus.RECOMMENDATION_TO_FRIENDS,
        ],
    )
    .annotate(
        answer_NPS=Case(
            When(
                answers__question__type=QuestionType.NPS,
                then=Cast(
                    'answers__answer', output_field=IntegerField()
                )
            )
        )
    )
    .filter(
        answers__choices__answer="Very disappointed",
        answer_NPS__gte=9
    ).order_by("-created")
)

Answer 1

嘗試這個：

 from django.db.models import Q

 Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT,
        answers__answer="Very disappointed",
     answer_num__gt=8,Q(answers__question__focus=QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN) 
   | Q(answers__question__focus=QuestionFocus.RECOMMENDATION_TO_FRIENDS)
    ).annotate(answer_num=Cast("answers__answer", IntegerField()))

Answer 2

可能使用django.db.models.Q會有所幫助。 以下行中的某些內容（尚未對其進行測試，因此可能需要進行一些調整）：

combined_query = (
    Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT,
        answers__question__focus__in=[
           QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN,
           QuestionFocus.RECOMMENDATION_TO_FRIENDS,
        ],
    )
    .annotate(answer_num=Cast("answers__answer", IntegerField()))
    .filter(Q(answers__answer="Very disappointed") | Q(answer_num__gt=8))
)

Answer 3

您可以使用| Q object 的運算符來組合兩個查詢：

from django.db.models import Q

query_combined = (
    Response.objects.filter(
        survey__event=12,
        survey__template=settings.SURVEY_POST_EVENT
    )
    .annotate(answer_num=Cast("answers__answer", IntegerField()))
    .filter(
        Q(
            answers__question__focus=QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN,
            answers__answer="Very disappointed"
        ) |
        Q(
            answers__question__focus=QuestionFocus.RECOMMENDATION_TO_FRIENDS,
            answer_num__gt=8
        )
    )
)

Answer 4

應該可以使用Q 表達式。 保存一個查詢是否值得讓代碼更復雜？ 無論如何，這是一個鏡頭，未經測試......

Response.objects.filter(
    survey__event=12,
    survey__template=settings.SURVEY_POST_EVENT
).annotate(answer_num=Cast("answers__answer", IntegerField())
).filter(
     ( Q(answers__question__focus=QuestionFocus.FEELING_ABOUT_ATTENDING_AGAIN) & 
       Q(answers__answer="Very disappointed") ) 
     |
       Q(answers__question__focus=QuestionFocus.RECOMMENDATION_TO_FRIENDS) &
       Q(answer_num__gt=8)
)

這並不完全相同，因為前半部分檢索到的所有對象現在也將被注釋。

Answer 5

您可以使用 itertools 的鏈 function。

from itertools import chain

combined = chain(query1, query2)