[英]How to create a django queryset object for inner join?
我有兩張桌子。
class DibbsSpiderDibbsMatchedProductFieldsDuplicate(models.Model):
nsn = models.TextField()
nsn2 = models.TextField()
cage = models.TextField()
part_number = models.TextField()
company_name = models.TextField(blank=True, null=True)
supplier = models.TextField(db_column='Supplier', blank=True, null=True) # Field name made lowercase.
cost = models.CharField(db_column='Cost', max_length=15, blank=True, null=True) # Field name made lowercase.
list_price = models.CharField(db_column='List_Price', max_length=15, blank=True, null=True) # Field name made lowercase.
gsa_price = models.CharField(db_column='GSA_Price', max_length=15, blank=True, null=True) # Field name made lowercase.
hash = models.TextField()
nomenclature = models.TextField()
technical_documents = models.TextField()
solicitation = models.CharField(max_length=32)
status = models.CharField(max_length=16)
purchase_request = models.TextField()
issued = models.DateField()
return_by = models.DateField()
file = models.TextField()
vendor_part_number = models.TextField()
manufacturer_name = models.TextField(blank=True, null=True)
product_name = models.TextField(blank=True, null=True)
unit = models.CharField(max_length=15, blank=True, null=True)
class Meta:
managed = False
db_table = 'dibbs_spider_dibbs_matched_product_fields_duplicate'
class DibbsSpiderSolicitation(models.Model):
line_items = models.IntegerField()
nsn = models.TextField()
nomenclature = models.TextField()
technical_documents = models.TextField()
purchase_request = models.TextField()
class Meta:
managed = False
db_table = 'dibbs_spider_solicitation'
對於 nsn 列上兩個表的內部連接,等效的nsn
查詢是什么? 我的看法 function 會像
def inner(request,nsn):
u_m = DibbsSpiderDibbsMatchedProductFieldsDuplicate.objects.filter(nsn2__icontains=id)
c_m = DibbsSpiderSolicitation.objects.filter(nsn__icontains=id)
obj = .......................
context = {'obj':obj}
return render(request,,"a.html",context)
查詢集應該根據共同的nsn返回兩個表的組合。
obj 應該返回u_m
和c_m
的組合。 如果u_m
僅包含一行而c_m
包含許多行,則 obj 必須復制 u_m 的值。
在 class DibbsSpiderDibbsMatchedProductFieldsDuplicate
下添加:
fkey = models.ForeignKey('DibbsSpiderSolicitation')
然后您可以輕松訪問他們的加入:
obj = DibbsSpiderDibbsMatchedProductFieldsDuplicate.Objects.filter(fkey__nsn).select_related()
現在你可以選擇你想用nsn2
做什么
obj = DibbsSpiderDibbsMatchedProductFieldsDuplicate.objects.extra(where = ['''SELECT *
FROM DibbsSpiderSolicitation
INNER JOIN DibbsSpiderDibbsMatchedProductFieldsDuplicate
ON DibbsSpiderSolicitation.nsn = DibbsSpiderDibbsMatchedProductFieldsDuplicate.nsn2;'''])
# or
obj = DibbsSpiderDibbsMatchedProductFieldsDuplicate.objects.raw('''SELECT *
FROM DibbsSpiderSolicitation
INNER JOIN DibbsSpiderDibbsMatchedProductFieldsDuplicate
ON DibbsSpiderSolicitation.nsn = DibbsSpiderDibbsMatchedProductFieldsDuplicate.nsn2;''')
obj = DibbsSpiderSolicitation.objects.filter(nsn__in=DibbsSpiderDibbsMatchedProductFieldsDuplicate.objects.nsn2)
抱歉,我無法測試任何內容。
您可以嘗試一些選項:
3、使用IN查詢按如下邏輯:
DibbsSpiderDibbsMatchedProductFieldsDuplicate.objects.filter(
nsn2__in=DibbsSpiderSolicitation.objects.filter(nsn__icontains='text_to_search').values('origin'))
首先,很棒的 model 名稱。 讓我們給它們起別名: DibbsSpiderDibbsMatchedProductFieldsDuplicate 是Apples ; DibbsSpiderSoliitation is Oranges
inner_qs = Apples.objects.all().extra(
tables=("yourapp_oranges",),
where=("yourapp_apples.nsn=yourapp_oranges.nsn",),
)
該文檔提到此 api 將被棄用: https://docs.djangoproject.com/en/4.0/ref/models/querysets/#extra
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