Django select_related Examples |Django select_related and prefetch_related |Django n+1 Query Problem

[@CodeBand]

Django prefetch_related | Django select_related vs prefetch_related : kzbin.info/www/bejne/a164f2ePhal3h8U

[@evanwhite4190]

This makes so much more sense than the documentation. Thank you!

[@CodeBand]

Glad to hear that...you can also checkout prefetch_related here : kzbin.info/www/bejne/a164f2ePhal3h8U

[@sayadahmedshaurov8639]

I was looking for this kind of explanation with example. What everyone does is just talks about theory. Thanks for making more sense by giving an example.

[@CodeBand]

Glad to hear that brother...😊

[@rahul_singh_rajput3292]

hhmm. delicious example 😌🔥..

[@CodeBand]

Thank you 🙌

[@oruchkin]

Very good thanks

[@CodeBand]

Most welcome

[@PrriyanshuSharmaa]

Thank You so much bro.

[@CodeBand]

Glad to hear that😊

[@vinodinti]

very good bro.

[@CodeBand]

Thanks a lot👍🏻

[@likeitthings8418]

thank you so much it helped me alot

[@CodeBand]

Glad it helped!

[@amirhosseinebneroomi7280]

amazing..

[@CodeBand]

Thanks a lot

[@mohammadfaisal2039]

Thank you, for good explanations

[@CodeBand]

Glad to hear that :)

[@hachhh]

Thank you!! Very clear explanation.

[@zoromahm]

So useful. Thanks for the video.

[@CodeBand]

Glad it was helpful!

[@mmafhbmmafhb3555]

thank you , you save me :)

[@CodeBand]

You're welcome!

[@user-ib4pu5zr7l]

Thank you ! The explanation is awesome)

[@CodeBand]

Glad to hear that...😊

[@behruzisaev2102]

Great explanation, bro. Thanks a lot!

[@CodeBand]

Glad it was helpful!

[@omidasadi2264]

it was great, thanks for sharing

[@CodeBand]

Glad you enjoyed it

[@ricardomoha14]

Your video is really great, up to the point and easy to understand, just onething.. Try being a bit faster.. I think the video could have been done in 5 minutes instead of 12.

[@CodeBand]

Thanks a lot and I have noted down the suggestion and will try to improve in future...

[@santiagobustamante970]

Great video and thanks for the tool, so useful! you saved hours of my life Thanks again man

[@CodeBand]

Glad it helped! Keep supporting 😊

[@MuhammadMahirQ8]

awesome broo.. highly appreciated

[@CodeBand]

Glad to hear that brother...Please share in your circle too...Thanks a lot... :)

[@nikeshthakor406]

Thanks

[@CodeBand]

Welcome.. :)

[@digambar6191]

Thanx sir

[@romanbush5164]

ThankS!

[@SAIFHASANAT-cm8xh]

thank you

[@harshamachine_learning7831]

Thanks for select related Please include prefetch related asap

[@CodeBand]

Definitely, I will upload it very soon. Thanks😊

[@CodeBand]

I have done the video of prefetch_related.😊 Please do let me know your suggestions in the comments. Thank you☺️ kzbin.info/www/bejne/a164f2ePhal3h8U

[@harshamachine_learning7831]

@@CodeBand video looks good, it covers key basic areas of that method

[@CodeBand]

Thanks❤️

[@azizbekgulomov2881]

Yeah good job! Keep it up!

[@CodeBand]

Thanks a lot👍🏻

[@josemanuel9137]

good explanation bro!

[@CodeBand]

Glad you liked it! Thanks for the support and keep supporting :)

[@rangabharath4253]

awesome

[@CodeBand]

Thanks a lot 😊

[@imranshaikh-bt5ln]

Hi which extension have you added on your browser to show requests and response time?

[@joshuahadap2373]

All I can say is I love you!

[@CodeBand]

Thanks a lot...Keep supporting... ☺️

[@bricegnanago409]

So good ! Now how make a left join query with select_related please

[@CodeBand]

Glad to hear that...have a quick research on left join and you'll find an answer...keep going👍🏻

[@pritamghosh270]

Great explained. Thanks 😊 . If I want objects of Employee table from Department then what to do? For an expample, I want some employees under a specific department. But I want it from the Department model not from Employee. That time what to do?

[@CodeBand]

Glad to hear that😊. In the case you mentioned, there is no chance of raising an N+1 query problem, because, department id will be there with you, and you just need to fetch all the employees with that specific dept. id, so at most 2 queries will be required. Hope this helps and I recommend you to watch the prefetch_related too... kzbin.info/www/bejne/a164f2ePhal3h8U

[@misfarsiddeek3105]

Brother, can you do a complete CRUD video with validation also? For the data input please use raw html forms. Without using Model Form or django form.

[@CodeBand]

Will try to do that in the future brother...Thanks for the suggestion... :)

[@misfarsiddeek3105]

@@CodeBand sure. I am waiting for that video.

[@CodeBand]

:)

[@danarardiwinanto]

Sir... I want to output count employee per department. let's say I have 8 departments, and I want to outputing all department with and without employee. How can I do this? Thankyou

[@CodeBand]

Sorry for the late reply... Did you figured it out?

[@danarardiwinanto]

@@CodeBand Yes, I have figured it out. I need to annotate (right join) my employee_id on department table. Should be like this: Department.objects.values('id_department').annotate(Counter=Count('employee')).values('id_department', 'Counter')

[@yollaifliandry495]

Thank you. By the way, is it possible to use select_related in class-based view ?

[@CodeBand]

Hey, for sure. It doesn't matter whether you use CBV/FBV.

[@FitriWibowo]

Very nice video, can we do the same thing with the Q keyword in Django

[@CodeBand]

Thanks a lot brother...There are a couple of ways of doing it...and this one stands out in terms of performance... :)

[@mfsdrawings8600]

👍🏻👍🏻👍🏻👍🏻❤️

[@CodeBand]

Thanks a lot brother... :)

[@jmdesros]

What if an employee doesn't have a department?

[@CodeBand]

Sorry for the late reply... That depends on the foreign key configurations.

[@RedElectrik]

You should remove "prefetch_related" from the title. You don't talk about it

[@RedElectrik]

Your also dont seem to have made a video about it anywhere

[@CodeBand]

Actually, I planned to do both in a single video, but unfortunately, I couldn't. I will definitely make a video on prefetch_related very soon, I planned it earlier, but somehow I got into some other videos. Sorry for the inconvenience caused.😔

[@RedElectrik]

Probs still a good idea to remove that out the title

[@CodeBand]

I have done the video of prefetch_related.😊 I also discuss when to use prefetch_related or select_related and their differences in the video. Please do let me know your suggestions in the comments. Thank you☺️ kzbin.info/www/bejne/a164f2ePhal3h8U

[@RedElectrik]

@@CodeBand I mean the title for this is still prefetch_related. Seems somewhat misleading

[@misfarsiddeek3105]

Hi. Great brother. May know that what is the different between mentioning Foreignkey, many to many and one to many in our model? Are they same?

[@CodeBand]

Thanks a lot brother...and about mentioning the foreign key and all, it totally depends on what kind of relationship you wanna use... I recommend you to watch this playlist...you will get a better idea... kzbin.info/aero/PLbasZIkCgHJH38p2WkC5GTsgoV_8hlQ4A And also please refer this article... hackernoon.com/django-orm-relationships-cheat-sheet-14433d6cf68c

[@misfarsiddeek3105]

@@CodeBand ok brother. I will refer these and ask from u if I have doubts. Thanx for helping me to learn django.

[@CodeBand]

@@misfarsiddeek3105 It's my pleasure brother...I will definitely help you out in case...Thanks :)

[@misfarsiddeek3105]

@@CodeBand thnx brother. ❤️

[@CodeBand]

@@misfarsiddeek3105 Welcome brother..:)

[@pankaj9575]

Getting error while migrations, Cannot add or update a child row,a foreign key constraint fails

[@CodeBand]

Please post your models.py so that I could help...😊

[@abhisharma8526]

hello sir ...please make a video of prefetch_related today...it's urgent for me ....please

[@CodeBand]

I'm very sorry...I have not scheduled any video for today...but I can assure, the next video is prefetch_related. Meanwhile, you can refer other resources. Thank you for the support😊

[@CodeBand]

I have done the video of prefetch_related.😊 kzbin.info/www/bejne/a164f2ePhal3h8U

[@deepanshuaggarwal7042]

we can use select_related only in ForeignKey case? or we can use with other joins also

[@CodeBand]

select_related is limited to single-valued relationships - foreign key and one-to-one. For more clarification, please see this post in SO. stackoverflow.com/questions/31237042/whats-the-difference-between-select-related-and-prefetch-related-in-django-orm

[@rojanshrestha822]

Thanks!! By the way, where is the video on prefetch_related??

[@CodeBand]

Glad it was helpful. I will actually do the prefetch_related in a future video... :) Thank you :)

[@CodeBand]

I have done the video of prefetch_related.😊 I also discuss when to use prefetch_related or select_related and their differences in the video. Please do let me know your suggestions in the comments. Thank you☺️ kzbin.info/www/bejne/a164f2ePhal3h8U

[@paranoia9142]

Will this work on 3 models?

[@CodeBand]

You can use __(double underscores) to access related field, see this : stackoverflow.com/questions/19909672/django-prefetch-related-on-multiple-models

[@RedElectrik]

You gonna remove "prefetch_related" for the title yet?

[@CodeBand]

I'm planning to do the next video in prefetch_related, so that I could put up both of them as a playlist and hence it would not be a big issue. Please let me know your view on this😊

[@CodeBand]

I have done the video of prefetch_related.😊 I also discuss when to use prefetch_related or select_related and their differences in the video. Please do let me know your suggestions in the comments. Thank you☺️ kzbin.info/www/bejne/a164f2ePhal3h8U

[@flowing_dance]

why people use fake accent ..its so irritating!

[@CodeBand]

Sorry to hear that...Honestly, it's not made up...its original😊