Django order by condition. I want to order the Queryset in this order.

Django order by condition Try Teams for free Explore Teams Jun 10, 2016 · To order in descending order, use a leading "-": class ModelName(models. functions import Collate Test. I can not sure but condition order is important as well. DateTimeField(auto_now_add=True . EDIT. Model): uploaded_by = models. latest(). order_by('-expiredate_salexpiredate') """ This is a simpler approach for the same problem I didn't know I could do. Model): contents = models. When you do the query in django, and you know, that you will get all elements from that query (i. Apr 26, 2012 · I answer to this old question for sharing an evolution of Django. filter(income For a large order table, where most queries focus on completed orders, use a simple condition: from django. type_list = [1,2,3,4] new_list = [] for each_type in type_list: latest_obj = MyModel. Model): status May 12, 2014 · I am attempting to perform an order_by based a m2m field, but it ends up creating duplicate entries in my queryset. Viewed 846 times Breakfast. filter(. order_by() was not working when applied to a queryset in my ModelView regardless of . Django 通过distinct和order_by进行查询 在本文中，我们将介绍使用Django的distinct和order_by来对数据库进行查询和排序的方法。无论是从单张表中查询数据还是进行多表关联查询，这两个方法都能够提供便捷的功能和良好的性能。 Nov 16, 2016 · order_by() will respect the order you put the arguments in. 11; We don't get deep into query compiler internals; To do so we need to override django. Please help! Thanks! VIEW. Tom,NY,2; John, LA, 5; Mike, NY, 1; Richard, SF, 4; and the city I am considering is NY, the query would return: Mike, NY, 1; Tom May 12, 2014 · I am attempting to perform an order_by based a m2m field, but it ends up creating duplicate entries in my queryset. For one date value it'll look like this: . I essentially want to order a query by a postgres function ('idx', taken from the above stackoverflow work) I've gone through trying to use model. " Thank you. annotate(expiredate_salexpiredate=Case(When(salexpiredate__isnull=False, then=F('salexpiredate')), default=F('expiredate'), output_field=DateField(),),). The order_by argument accepts an expression on which you can call asc() and desc(), a string of a field name (with an optional "-" prefix which indicates descending order), or a tuple or list of strings and/or expressions. This wasn't working, and adding the order_by fixed it. Aug 28, 2018 · If you want to order specific objects by id at the top of a queryset, you can order on a conditional expression - for example, to put the current user at the top, and order other users by name: from django. extra(select={"day_mod": "strftime('%d', date_modified)"}, order_by=['-day_mod', '-score']) This works for filtering with no other conditions, but if I apply a condition on the filter such as a category: Jul 3, 2017 · I have a 73 GB big table table1 . CharField(max_length=128 May 6, 2015 · You can call filter() on it, order_by(), etc. How would one go about ordering a queryset by whether or not a many to many relationship condition is true? i. To sort QuerySets, Django uses the order_by() method: Order the result alphabetically by firstname: In SQL, the above statement would be written like this: By default, the result is sorted ascending (the lowest value first), to change the direction to descending (the highest value first), use the minus sign (NOT), - in front of the field name: Jan 26, 2024 · from django. – I have a queryset that I want to paginate through alphabetically. 1 (currently beta) adds aggregation support. So, in the 1. models import DateField, Case, When, F: queryset. CharField() class Meta: ordering = [ Cast("street_number", output_field=models. OrderBy Nov 12, 2024 · Our query set goal is to order these items from high to low priority. List is like below: orderbyList = ['check-in','check-out','location'] I am writing a query like this: modelclassinstance. The Q objects are used to form complex filtering by joining several conditions through logic operators like OR, AND, and NOT. The end result has to be one QuerySet object (not a list), as I wish to pass the ordered QuerySet to Django's ModelMultipleChoiceField form field. Ask Question Asked 3 years, 10 months ago. 2 and PostgreSQL 10. Sep 12, 2022 · Say one has this simple model: from django. models import User users = User. For example, to order a QuerySet of books by the number of authors that have contributed to the book, you could use the following query: Dec 4, 2019 · For filter_condition I've written a function that compares the filter_condition and assigns the Django queryset API. How can I create a subprogram function that returns a list of Jun 4, 2010 · Django 1. I want to order the Queryset in this order. In contrast, iterating over a QuerySet will take advantage of your database to load data and instantiate objects only as you need them. filter(run='run_1'). 2) the "_pressed" arrow images are never shown. Be warned, though, that this could have a large memory overhead, because Django will load each element of the list into memory. F and django. filter( To continue on @iuysal answer: To make it generic you need to pass the key too as parameter, to do that you need to pass a dictionary, here's how I did it: Sep 17, 2017 · I moved the condition to main query, check if subquery return None then use Flat model field. Sep 21, 2014 · So, django has to send new request to database: for r in results. In this case status = 4 is the first order_by parameter, but it could be combined with any additional conditions. You can pull all records, turn them into a list, and sort them, although that may be inefficient and slow. Dec 1, 2021 · There are two fields: start_date and end_date. Django order_by, 多个字段排序和优先级. 2, there is alias() very well suited for this case :. Standard for sorting. 8 in you extra, there is just need to trick django, so it will create joins and group by for us. payment_no = models. Model): street_number = models. I have been searching through the django documentation and related questions on s Jan 18, 2011 · Django; is it possible to have a default value for queryset. contrib. Model): title=models. Dec 24, 2014 · child_set is the default related_name of your parent field in the Child model. Your query can be done with something like: from django. – Jan 9, 2025 · Thank you @charettes, with window function the returned result are those which I expected when using the initial subquery and the overall cost of the operation has decreased (which was my main goal, since this operation is a bit frequent). order_by('id'). Sep 6, 2023 · We can use the Q objects in django. @Greg Thank you! I new that the ordering and order_by() causes issues with distinct but I didn't know how to solve it - although it is in the QuerySet API docs under order_by() "If you don’t want any ordering to be applied to a query, not even the default ordering, call order_by() with no parameters. e. annotate( qs_order Oct 13, 2024 · Introduction: The Index. "AssignmentModule"s have a due date DateTimeField field . from django. I have a User model and a Submission model. 0. You can either order after you fetch the querysets or write raw SQL. Use the string “?” to order randomly. Feb 5, 2015 · I have three model: class Category(models. . If there is a requirement that we need to sort the Employees in ascending order by salary then we can use order_by in Django. id, then=0 Mar 25, 2020 · Model. Because that condition effect in turn of list value. I need to sort my MonthlySpending objects by its index. Mar 14, 2018 · In django, Q is intended to be used inside filter(), exclude(), Case etc. django import F MyModel. This can be particularly useful when working with very large datasets, where most queries target a specific subset of rows. order_by('datetime__time') doesn't work as it is part of the same model. Most of my queries involve fetching the latest 100 entries in the table which satisfy some condition. filter(name="john") funky_queryset |= MyModel. db. Aug 30, 2021 · All contacts that have "A" as a city order by preference; And after that all contacts that don't have "A" as a city order by preference; So basically if my Contact table (name, city, preference) had something like. 1. I have tried the dictsort from django template but does not work. It has only one drawback: it doesn't define what type is outputting (it's always boolean and django can assume that in every case when Q is intended to be used. Feb 10, 2021 · Django Order QuerySet by Min Value from Child Table. To load new data from the server without reloading, you will have to send a new request in the background using AJAX. May 23, 2017 · Now my problem has moved onwards to the Django ORM layer. employees = Employee. objects from my_project. utils. order_by('-id')[:10] it will return a list and the problem with that is you cannot perform further QuerySet methods on list Jun 12, 2021 · I have multiple projects in my subprogram, each with a different cost which I'm calculating in a custom function in my project model. order_by(Substr('my_char_field',3)) Oct 13, 2024 · Introduction: The Index. PY Mar 18, 2023 · An interesting problem with this: let's say you order users with: ordering = ('-last_login',), which can be null, i. IntegerField() In SQL you can perform an order by with a condition e. order_by(F('material_cost') + F('labor_cost'))[0] I found other answers django order by date in datetime / extract date from datetime using . Sep 2, 2014 · This of course returns the objects, but in the order of the models meta ordering property, and I wish to get the records in the order of the pks in pk_list. functions import Cast class Address(models. For example. class Submission(models. 8 order_by() accepts not only field names but also query expressions. filter_dict = dict([filter. filter(income Aug 30, 2021 · All contacts that have "A" as a city order by preference; And after that all contacts that don't have "A" as a city order by preference; So basically if my Contact table (name, city, preference) had something like. Assignments not submitted and due date already passed will be in overdue and these should come first. day = # some date price = Price. They can also be combined and nested with other expressions. Each Submission has a ForeignKey field called user_submitted for the User who uploaded it. Order_by también permite el orden descendente, para hacerlo no se coloca algún termino como en base de datos. Jun 24, 2020 · How can I make order_by fields in a single query dependent on field values? e. Related. May 31, 2017 · Yes, but you can't do that conditionally. order_by( Case(When(id=request. desc(nulls_last=True)) # or MyModel. ForeignKey(Category) class "If the model has a default ordering defined in class Meta, the . I have two problems now, which is that: 1) the order_by is only applied on the first page. extra: Article. 'sort_order_true', '-sort_order_false', You should be able to use a Func expression to convert your datetimes into timestamps so that you can negate them. If you need to order the resulting queryset using some of the new fields or tables you have included via extra() use the order_by parameter to extra() and pass in a sequence of strings. union(qs1, qs2) The downside is that I lose access to queryset. user. values('country'). Django identifica el orden descendente aplicando un signo dentro de los paréntesis. Django doc – Oct 16, 2021 · First, using order_by('?') could have a larger effect on performance than anything else, depending upon the size of the Item table. expressions. " – order_by() ¶ Annotations can be used as a basis for ordering. annotate( qs_order Dec 16, 2016 · While it's possible to fetch and do the sorting in the client side, you can also use the Substr function to do this at the server side. nodes. annotate( qs_order=models. Django是一个流行的Python web框架，提供了许多强大的功能来简化开发过程。其中一个基本功能是对 May 3, 2017 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. filter( flats=models. filter() being present or not. order_by(F('price'). IntegerField()) ) # Each constant should basically act as the position where we want the # queryset to stay queryset_1 = MyModel. Option 1: Order in Python. desc(). Django supports ordering by values of one or more fields. This also happens Dec 14, 2013 · This was the only thing that worked for me running Django 2. order_by('id') Blog. The ordering controls the order in which the expression is applied. Sample: import datetime from django. Jul 13, 2021 · class Order(models. annotate() to add a True or False value for any given condition. I want to write a Django query equivalent to this SQL query: SELECT * from user where income >= 5000 or income is NULL. What you want will need custom condition checking and then ordering. I'd suggest changing it to I am trying to get the latest Django model object but cannot seem to succeed. order_by('name') I want to compare the first letter of the employee's name name[0] to the letter that If you too are using Django Rest Framework, I ended up here searching for why . Neither of these are working: obj = Model. py ordering using foreign field. Requiring an order_by to make a group by work is very intuitive, and an important quirk of Django's ORM to understand. order_by(*order_by_list) Here, we can append the column names dynamically to order_by_list As of Django 1. order_by(Collate('nimi', 'et_EE')) Since Django 1. At the moment I am doing: queryset. Dec 16, 2019 · You can convert your string to dictionary and then use that as the input for the filter:. all(). Also Dec 30, 2019 · You can only order by database fields. order_by('country', '-order_count') # This will generate a query similar to: # SELECT country, COUNT(orders) AS order_count # FROM customer # GROUP BY country # ORDER BY country ASC, order Nov 14, 2022 · While the specifics are going to depend upon precisely what you’re doing in the query and in the view, the general idea is that you write code to examine the queryset to determine which elements of the queryset are duplicates of other elements. Dec 19, 2015 · @Jarret's answer (do the sort in Python) works great for simple cases. This is probably not a good idea , though, since you are sending the same query set ordered in a different way. Model): category_name = models. Sep 13, 2019 · Order by descendente. CharField(max_length=80) date_created=models. first() # Get n Random objects: random_objects = MyModel. I want to order by multiple fields with Django ORM. order_by('creation_date') And then later I wanted instances. I am using Django as my backend for this web app. Assignments not submitted should come in order of due dates , earliest should come first. db import models from . There is one line of code that you need to change in the ShowDetails Action method under view. values() The people who made Django prefer to put all the SQL-affecting methods first, followed (optionally) by any output-affecting methods (such as values()), but it doesn’t really matter. order_by() clause is obligatory for proper results. Jul 4, 2011 · Slicing of QuerySets returns a list which means if you do like: >>> Model. , if field status==10 then sort ascending if field status==20 then sort descending Sep 6, 2023 · Sort the Employees in A scending order; Sort the Employees in Descending order; Sort the Employees in A scending order. Keep it mind it will return a list, not a queryset anymore (inspired from this answer) and that you end up using magic strings (what if the user uses Entrées instead of Starters?): Is it possible to use the django ORM to order a queryset by the sum of two different fields? For example, I have a model that looks like this: class Component(models. If you don't need to define your own get_queryset, don't! Nov 26, 2023 · I have three querysets of the same columns that I would like to handle as one object. My query is Mar 18, 2010 · When you specify field names, you must provide an order_by() in the QuerySet, and the fields in order_by() must start with the fields in distinct(), in the same order. condition option in Django allows you to create partial indexes that only apply to a subset of rows in a table, rather than the entire table. annotate(num_children=Count('child_set')). ForeignKey(User, to_field='username') date = models. Model): n = models. Jan 5, 2016 · Force evaluation of a QuerySet by calling list() on it. How to construct the Django queryset filter? User. The generated query is: Jun 3, 2010 · from django. but it simply creates condition that apparently can be used anywhere. order_by('?')[:n] Problem: It uses SQL's ORDER BY RAND(), which may go on your criminal record as a misdemeanor in certain countries in the near future. time') this doesn't work and also . IntegerField()), ] From the doc about ordering: You can also use query expressions. models import Q class Order(models. Apliquemos el signo negativo para ambas vistas. models import User from django. sort_order_true=Case( When(bool_val=True, then=('date_a')), default=None. This is kind of funky, but doing something like this should give you what you need: You could sort it like this: funky_queryset = MyModel. I tried the other suggestions involving matching the order of arguments for order_by and distinct and those did not solve the issue. order_by('-publish') Documentation for ascending/descendig order is here. filter(category__id=1). order_by(*ordering) After setting ordering list you can apply that condition in query like upper code. I would like it so that order_by is run and then the entire ordered list is paginated. I have used the following (here Tasks is my model and datetime is the field) Tasks. Tom,NY,2; John, LA, 5; Mike, NY, 1; Richard, SF, 4; and the city I am considering is NY, the query would return: Mike, NY, 1; Tom Aug 3, 2015 · Thanks for contributing an answer to Stack Overflow! Please be sure to answer the question. CharField(max_length=32, blank=True) . order_by('-max_weight') This sorts people by their heaviest roles, without returning duplicates. Model): material_cost = CostField() labor_cost = CostField() and I want to do something like this: component = Component. django models. functions import Substr MyTable. See my updated answer. Since Django 3. Django ORM: query of two models. models import MyModel # Add an extra field to each query with a constant value queryset_0 = MyModel. Both start_date and end_date are empty values. Feb 15, 2013 · Django1. extra(order_by ) or simply order_by but I believe both of these need the order_by parameter to be an attribute or a field known to Django. Querying for multiple objects with Django-orm. I don't have predefined set of data. Nov 24, 2021 · Here is a link for the Django docs on making queries that span relationships: Django order by foreign key. values(). Apr 15, 2012 · This is code listing tasks and sorting them by three conditions desc and asc. models import Case, When from django. extra( select={'total_food':'count_eggs + count_bacon'}, order_by=('total_food',) ) This seems to work for many, but Django docs appear to dissuade this solution. db import models from django. split('=')]) list = catalog['model']. When you define an order_by() clause, the aggregates you provide can reference any alias defined as part of an annotate() clause in the query. CharField(max_length=128, unique=True) category_alias = models. OuterRef('pk')). latest() give me the correct instance. order_by('-created_at Oct 9, 2023 · I have these models: class Project(models. If you've specified a different one, you will have to change the code accordingly. For example, SELECT DISTINCT ON (a) gives you the first row for each value in column a. 在本文中，我们将介绍Django中的order_by方法，以及如何使用多个字段进行排序和设置排序优先级。 阅读更多：Django 教程. Apr 12, 2016 · I am getting order_by fields in the form of a list. Jan 20, 2015 · If you want to get newest posts then you need to add -sign to the field name in the order_by method: list_blog_canada = Blog. 2: from django. Model): check_in = models. A. annotate(order_count=Count('orders')). DateTimeField(auto_now_add = True) class Meta: ordering = ["-check_in"] Fields without a leading “-” will be ordered ascending. my model has field payment_no to store string that have 2 syntax Avoiding race conditions using F() ¶. Apr 16, 2022 · Yes, there is a manual way. DateTimeField(auto_now_add=True) category = models. , no OFFSET and LIMIT), then you can process those elements in python, after you get them from database. 2. Jun 20, 2017 · When i get my IDs out using django orm: obj = MyIDs. Jan 5, 2025 · ORDER BY with other fields. If two Python threads execute the code in the first example above, one thread could retrieve, increment, and save a field’s value after the other has retrieved it from the database. Asking for help, clarification, or responding to other answers. models import ContentType from django. filter(). Sep 17, 2010 · instances = MyModel. But you are interested in the most recent users, so the null last_login users appearing ahead of the most recently logged in is quite annoying. order_by('-num_childen') Jul 1, 2021 · # Sorting columns with id, name, username in dynamically order_by_list = [] # sort by name order_by_list. Or you can add a database field called name and fill it in via a post-save hook; then you can sort it using order_by. If you don’t specify an order, you’ll get some arbitrary row. The order_by function is run and completed before the request is completed. models import Count customer_counts = Customer. order_by('?'). annotate(max_weight=Max('roles__weight')). latest(), but it would not give me the correct instance, in fact it gave me the first instance. order_by('datetime. Is it possible to use the value of one of these custom methods that I've defined as a property in a model with order_by()? Here is an example that demonstrates how the property is implemented. append('name') # And second username sort along with name order_by_list. models import Count ordered_parents = Parent. Modified 3 years, 10 months ago. ). TextField() writer = models. 10+ world, What is the best/correct way to do this type of filtering on the sum of two (or more) fields in Django Jul 23, 2018 · For my case it will be very important to get the order right. +) I am not good at English, but i do my best to explain my code. select * from foo orber Apr 5, 2013 · This is too localised requirement really. the user never logged in. It has to read the entire result set, shuffle it, then return the desired subset. models. contenttypes. def assign_filter_condition(self Mar 9, 2017 · I don't think Django queryset has a mechanism to order by a list of field value. order_by('?'): # new query was send to database # Solution. Tasks. Only when I set order_by to -creation_date or actually removed the order_by from the query did . Django order_by() 方法在用 filter() 过滤数据时不能正常工作 在本文中，我们将介绍 Django 框架中的 order_by() 方法以及它在使用 filter() 方法进行数据过滤时的一些问题。我们将解释为什么 order_by() 方法在一些情况下不能正常工作，并提供一些解决办法和示例说明。 from django. Jan 29, 2016 · I'm currently learning Django and some of my models have custom methods to get values formatted in a specific way. (start_date = Null, end_date = Null) Start_date Most recently and Apr 18, 2017 · You can use simple a . Another useful benefit of F() is that having the database - rather than Python - update a field’s value avoids a race condition. class Publication(models. Value(0, models. 1. models import Max People. The expected result should be the id’s in the following order: [2, 5, 1, 3, 4] May 27, 2013 · my_words = Wiki. For priority levels with multiple items, we'll also order by title to keep the results consistent. filter(testfield=12). db import models class Foo(models. If I understand correctly, I think you need consistently ordered result set every time, You can use something like order_by('score','id') that will first order by the score first and then by the auto-increment id within the score having same values, hence your output being consistent. Conditional expressions can be used in annotations, aggregations, filters, lookups, and updates. I have also Jan 29, 2016 · I'm currently learning Django and some of my models have custom methods to get values formatted in a specific way. Model): name = models Apr 5, 2016 · For older Django versions see the original information below the following code sample: # Starting with Django 3. Nov 18, 2015 · @HassanBaig putting sub-query will be really slow in this case, but you can use SQL code from queries created by django >= 1. filter(other_condition) Jun 21, 2016 · Exactly how random must these be? Does it have to be different for each user, or is it merely the appearance of randomness that is important?. filter(type=each_type). Provide details and share your research! But avoid …. By randomly ordering the ENTIRE table with SQL: # Get one random object: random_object = MyModel. order_by('ID') I get them out in the order of the first number: 1/17 112/17 2/17 2345/17 67/17 8974/16 9/17 98/15 However as the number after the / is the year, I would like to order them by the year then number. models to create an OR, AND, and NOT filter in a Django query. auth. If it is the latter, then you can simply add a field called ordering to the model in question, and populate it with random integers. As soon as you have a large table and want to, say, pull only the first page of results sorted in a certain way, this approach breaks (you have to pull every single row from the database before you can do the sort). Model): . functions import Coalesce, Value from app import models # Coalesce works by taking the first non-null value. – May 25, 2020 · All "UserEnrolment"s have a completion_status. g. That means that these two calls are identical: Blog. However, you won't be able to create an index on the word field if the type is TextField, so sorting by word will take a long time if there are a lot of rows in your table. contenttypes import generic class Note(models. py. (DateField). Same as annotate(), but instead of annotating objects in the QuerySet, saves the expression for later reuse with other QuerySet methods. Is there a way around this? I mean, those querysets came from the same model but were generated by different queries. append('owner__username') Room. 8 you can use Coalesce() to convert NULL to 0. ), sort_order_false=Case( When(bool_val=False, then=('date_b')), default=None. order_by(*orderbyList) Everything I'm expecting in a list is dynamic. 4: How to use order_by in template? models. latest() obj = Model. For example, to order by check_in field ascending, use this: Dec 20, 2017 · I wanted to order a query set on the basis of a time of a datetime field. order_by('word') should return the records in the correct order. nullslast()) Cons: Easy migration to Django 1. 介绍. objects. order_by(). kjlfp iaqqfod enpkpnq zkj msgi thj incsns ahcpy lplajzx wtwwt