Hi , Please lookandfeel on Moving an object from one database to another¶ <https://docs.djangoproject.com/en/2.0/topics/db/multi-db/#moving-an-object-from-one-database-to-another>
https://docs.djangoproject.com/en/2.0/topics/db/multi-db/#moving-an-object-from-one-database-to-another On Sat, Nov 30, 2019, 15:39 Dvenum <dvenum...@gmail.com> wrote: > Integr@te System, > > This is True: id(company) == id(company_value.company) > So, we have exact the same object company, .id is ready on .save() call, > but internal meta dictionary still has None, because it was none when > company_value created. > > On Sat, Nov 30, 2019 at 2:39 PM Integr@te System <datacentral...@gmail.com> > wrote: > >> Hi Dvenun, >> >> Bc of Django implement accord to python, of cause child inherit from >> parent existence. >> >> >> https://docs.python.org/3.7/library/functions.html#id >> >> >> On Sat, Nov 30, 2019, 13:30 Dvenum <dvenum...@gmail.com> wrote: >> >>> Interest idea and it works, but not necessary: >>> company = Company() >>> #company.id is None >>> companies.append(company) >>> Company.objects.bulk_create(companies) >>> #company.id is 1 >>> >>> Instead to ask pk from database, it can be used from >>> company_value.company.id. Django save pk value to internal meta >>> (models/base.py) and does not update it. This works too: >>> value.company = value.company # pk updated >>> >>> I want to ask, each child object should be created only when parent is >>> saved to db? Maybe django has something to cover this case? >>> >>> >>> On Sat, Nov 30, 2019 at 7:52 AM Charles Lee <charleslee...@gmail.com> >>> wrote: >>> >>>> I have an idea. >>>> >>>> 1. `bulk_create` all companies. >>>> 2. `Filter`(SELECT) all `Company` and make it dictionary for >>>> retrieving company fast. >>>> 3. >>>> 1. company_dict = { >>>> ’Name’: ‘pk’, >>>> ... >>>> } >>>> 4. Create a list of `CompanyValue` with company name and >>>> company_dict. >>>> 5. `bulk_create` the list. >>>> >>>> >>>> I'm not sure if it will work because I haven't implemented it, but I >>>> hope it helps. >>>> >>>> 2019년 11월 29일 금요일 오후 9시 42분 0초 UTC+9, Maxim Bulatov 님의 말: >>>>> >>>>> Hello, >>>>> >>>>> I have lot of lists like follow: >>>>> (Name1): (V1, V2, V3, V4, ..) >>>>> >>>>> And I use many threads to create many db objects: >>>>> company = Company(Name) >>>>> for x in vector: >>>>> v = CompanyValue(company=company, value=x) >>>>> values.append(v) >>>>> >>>>> class CompanyValue(models.Model): >>>>> company = models.ForeignKey('Company', on_delete=models.CASCADE) >>>>> value = FloatField >>>>> >>>>> This pool of threads return all lists, what I combine, filter and want >>>>> put to database in one bulk_create call. >>>>> Suddenly, I found, company.id is not ready to be linked in >>>>> CompanyValue, follow code does not works: >>>>> Company.objects.bulk_create(companies) >>>>> CompanyValue.objects.bulk_create(values) # value.company_id is >>>>> null here >>>>> >>>>> No way to save objects in my threads, because I need to filter objects >>>>> and can do it only when all of them are collected. Also, it has >>>>> performance >>>>> issues 100k+ of requests is slowly enough. I have two ways to resolve: >>>>> 1. I can make intermediate class or tuple and create CompanyValue >>>>> objects only when companies is saved to db. Hard to support, hard to >>>>> filter, not so clean. >>>>> 2. I can use dirty hack to update _id field: >>>>> for v in values: >>>>> v.company = v.company >>>>> >>>>> Can you advice more ways for me? It seems, I don't know something from >>>>> django features to make it elegant. >>>>> I see 11 years old issue here ( >>>>> https://code.djangoproject.com/ticket/9553 >>>>> <https://code.djangoproject.com/ticket/9553#no1>) and it marked as >>>>> intended behaviour. >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Django users" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to django-users+unsubscr...@googlegroups.com. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/django-users/af2a0f27-7234-4210-8627-1ad8982da805%40googlegroups.com >>>> <https://groups.google.com/d/msgid/django-users/af2a0f27-7234-4210-8627-1ad8982da805%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>> >>> >>> -- >>> dvenum >>> dvenum...@gmail.com >>> >>> -- >>> You received this message because you are subscribed to the Google >>> Groups "Django users" group. >>> To unsubscribe from this group and stop receiving emails from it, send >>> an email to django-users+unsubscr...@googlegroups.com. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/django-users/CAHBRYSd1MC5mL3oWTfzqc%2BXXcWxVnDqLpJ5HsEGk2GHFd917eQ%40mail.gmail.com >>> <https://groups.google.com/d/msgid/django-users/CAHBRYSd1MC5mL3oWTfzqc%2BXXcWxVnDqLpJ5HsEGk2GHFd917eQ%40mail.gmail.com?utm_medium=email&utm_source=footer> >>> . >>> >> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to django-users+unsubscr...@googlegroups.com. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/CAP5HUWqW7gZVR1u6-%2BAkMhB5dZeRHiXzLrSQvmiL7O3diT9OfA%40mail.gmail.com >> <https://groups.google.com/d/msgid/django-users/CAP5HUWqW7gZVR1u6-%2BAkMhB5dZeRHiXzLrSQvmiL7O3diT9OfA%40mail.gmail.com?utm_medium=email&utm_source=footer> >> . >> > > > -- > dvenum > dvenum...@gmail.com > > -- > You received this message because you are subscribed to the Google Groups > "Django users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to django-users+unsubscr...@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/django-users/CAHBRYSf9iMaMmT1osqvP2uiu%2BbyN%2BKDkMOqZXdYcfo8Pt%2B1_Sw%40mail.gmail.com > <https://groups.google.com/d/msgid/django-users/CAHBRYSf9iMaMmT1osqvP2uiu%2BbyN%2BKDkMOqZXdYcfo8Pt%2B1_Sw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "Django users" group. To unsubscribe from this group and stop receiving emails from it, send an email to django-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/django-users/CAP5HUWq01D-mbPRA-mV_vfn-a7jKj52n-ayk_mH7_SmWn9GD2A%40mail.gmail.com.
