Re: QuerySet.iterator together with prefetch_related because of chunk_size

2018-10-15 Thread tobias . kroenke 
Thank you for your feedback. I would like to answer some statements to 
either convince you or make it more clear, where my idea stems from:

The fundamental reason why iterator() cannot be used with 
> prefetch_related() is that the latter requires a set of model instance to 
> be materialized to work appropriately which chunk_size doesn't control at 
> all.
> In other words chunk_size only controls how many rows should be fetched 
> from the database cursor and kept into memory at a time. Even when this 
> parameter is used, iterator() will only materialize a single model instance 
> per yield.
>
 
It should be easily possible to change the involved code of ModelIterable 
to materialize the retrieved rows in batches. After materializing the batch 
/ chunk, it could do the prefetching.
 

> Given that iterator() always ignored prefetch related lookups instead of 
> erroring out when they were specified make me feel like turning such a 
> feature on by default could be problematic as it could balloon the memory 
> usage which is the main reason why iterator is useful anyway.
>

I would argue, that users who thoughtlessly applied prefetching together 
with iterator now actually get, what they thought of: less DB query round 
trips traded against a little more memory usage.

Best,
Tobi

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Re: Fellow Reports - October 2018

2018-10-15 Thread Tim Graham 


Week ending October 13, 2018

Triaged

---

https://code.djangoproject.com/ticket/29790 - Migration that switches a 
model to a UUID primary key fails with "duplicate column name: id" 
(accepted)

https://code.djangoproject.com/ticket/29834 - Union queryset with ordering 
breaks on ordering with derived querysets (accepted)

https://code.djangoproject.com/ticket/29830 - EmailMessage may ignore quote 
printable encoding (accepted)

https://code.djangoproject.com/ticket/29839 - Make leading character in 
quote/unquote in contrib.admin.utils configurable (wontfix)

https://code.djangoproject.com/ticket/29837 - Allow email sending with a 
newline in the subject (wontfix)

https://code.djangoproject.com/ticket/29844 - Cast DecimalField to 
FloatField rounds to integer on MySQL (duplicate)

https://code.djangoproject.com/ticket/29845 - Casting FloatField to 
DecimalField causes MySQL/MariaDB SQL syntax error (accepted)

https://code.djangoproject.com/ticket/29843 - Create permissions using 
migration operations rather than using the post_migrate signal (accepted)

https://code.djangoproject.com/ticket/29833 - Show change form edit links 
on read-only foreign keys (wontfix)

https://code.djangoproject.com/ticket/29826 - urlize does not handle HTML 
angle brackets correctly (wontfix)

Authored

--

https://github.com/django/django/pull/10505 - Refs #29826 -- Removed unused 
characters from urlize configuration.

Reviewed/committed

--

https://github.com/django/django/pull/10487 - Refs #27795 -- Removed 
force_bytes() usage from django/utils/http.py.

https://github.com/django/django/pull/10504 - Fixed #29814 -- Added support 
for NoneType serialization in migrations.

https://github.com/django/django/pull/10499 - Fixed #29832 -- Updated 
Roboto font to v2.137.
https://github.com/django/django/pull/10507 - Simplified 
django.utils.html.urlize().

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Re: invalid literal for int() with base 10: ''

2018-10-15 Thread Moses Mugisha 
  Can you post to stackoverflow instead?. You are probably passing a string
instead of an integer hence the conversion error.

Best
Moses

On Mon, Oct 15, 2018 at 4:47 PM Naamara Hannington 
wrote:

>
> Hey guys. I am developing a django ecommerce site but whenever I click on
> continue to pay button, I get the following error "
>
> invalid literal for int() with base 10: ''
>
> ", what could be the error please.
> Thank you guys
> --
> Naamara Hannington Kangwangye
> Software Developer and CEO Softprog Uganda.
> Web Developer at Crown Integrated Marketing.
> Bsc Comp. Science, KYU
> +256775719034/+256706431210
>
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Re: column "" must appear in the GROUP BY clause or be used in an aggregate function

2018-10-15 Thread Kotha bondhu Mithun 
sorry friendiam also try it


On Mon, Oct 15, 2018 at 7:37 AM 徐军明  wrote:

> Django 2.1.2, Postgres 10
>
> Model:
> class Product(models.Model):
> product_id = models.AutoField("产品ID", primary_key=True)
> ...
>
> class SpecItem(models.Model):
> spec_id = models.AutoField(primary_key=True)
> product = models.ForeignKey(Product, on_delete=models.CASCADE,
> related_name="product_specs", null=True)
> price = models.FloatField("价格", default=0)
> ...
>
> When exwcute
> qs = Product.objects.filter(valid=1)
> serializer = ProductSerializer(
> qs.annotate(cnt=Count("product_specs"),
> min_price=Min("product_specs__price")).filter(cnt__gt=0)
> .order_by("min_price")[offset:offset + limit],
> context={"request": request},
> many=True)
>
> It says django.db.utils.ProgrammingError: column
> "prome_product.product_name" must appear in the GROUP BY clause or be used
> in an aggregate function
>
>
> Can anyone help me?
>
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Re: invalid literal for int() with base 10: ''

2018-10-15 Thread Adam Johnson 
This mailing list is for the development of Django itself, not for support.
Use the django-users mailing list for that, or IRC #django on freenode, or
a site like Stack Overflow.

On Mon, 15 Oct 2018 at 14:57, Moses Mugisha  wrote:

>   Can you post to stackoverflow instead?. You are probably passing a
> string instead of an integer hence the conversion error.
>
> Best
> Moses
>
> On Mon, Oct 15, 2018 at 4:47 PM Naamara Hannington 
> wrote:
>
>>
>> Hey guys. I am developing a django ecommerce site but whenever I click on
>> continue to pay button, I get the following error "
>>
>> invalid literal for int() with base 10: ''
>>
>> ", what could be the error please.
>> Thank you guys
>> --
>> Naamara Hannington Kangwangye
>> Software Developer and CEO Softprog Uganda.
>> Web Developer at Crown Integrated Marketing.
>> Bsc Comp. Science, KYU
>> +256775719034/+256706431210
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "Django developers (Contributions to Django itself)" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to django-developers+unsubscr...@googlegroups.com.
>> To post to this group, send email to django-developers@googlegroups.com.
>> Visit this group at https://groups.google.com/group/django-developers.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/django-developers/CAGra9xypcY1YcWJ-hbkH0h8pj1-%3D05Xzss_LH3AqmwSo2irsjA%40mail.gmail.com
>> 
>> .
>> For more options, visit https://groups.google.com/d/optout.
>>
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Re: column "" must appear in the GROUP BY clause or be used in an aggregate function

2018-10-15 Thread Adam Johnson 
This mailing list is for the development of Django itself, not for support.
Use the django-users mailing list for that, or IRC #django on freenode, or
a site like Stack Overflow.

On Mon, 15 Oct 2018 at 02:36, 徐军明  wrote:

> Django 2.1.2, Postgres 10
>
> Model:
> class Product(models.Model):
> product_id = models.AutoField("产品ID", primary_key=True)
> ...
>
> class SpecItem(models.Model):
> spec_id = models.AutoField(primary_key=True)
> product = models.ForeignKey(Product, on_delete=models.CASCADE,
> related_name="product_specs", null=True)
> price = models.FloatField("价格", default=0)
> ...
>
> When exwcute
> qs = Product.objects.filter(valid=1)
> serializer = ProductSerializer(
> qs.annotate(cnt=Count("product_specs"),
> min_price=Min("product_specs__price")).filter(cnt__gt=0)
> .order_by("min_price")[offset:offset + limit],
> context={"request": request},
> many=True)
>
> It says django.db.utils.ProgrammingError: column
> "prome_product.product_name" must appear in the GROUP BY clause or be used
> in an aggregate function
>
>
> Can anyone help me?
>
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-- 
Adam

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