Styjun

Can you create a free-floating MASYU puzzle?

Can the Four Elements monk's Shape the Flowing River elemental discipline create stairs by expending a single ki point?

What factors could lead to bishops establishing monastic armies?

Category-theoretic treatment of diffs, patches and merging?

Floating Pumice Road. Slab Size

Why is whale hunting treated differently from hunting other animals?

How was the website able to tell my credit card was wrong before it processed it?

What are the consequences for a developed nation to not accept any refugee?

Passwordless authentication - how invalidate login code

Why do people prefer metropolitan areas, considering monsters and villains?

Why did the frequency of the word "черт" (devil) in books increase by a few times since the October Revolution?

Can one block with a protection from color creature?

Can a USB hub be used to access a drive from two devices?

Difference between [[ expr1 || expr2 ]] and [[ expr1 ]] || [[ expr2 ]]

How to evaluate the performance of open source solver?

I don't want to be introduced as a "Minority Novelist"

How do I talk to my wife about unrealistic expectations?

As a supervisor, what feedback would you expect from a PhD who quits?

Gory anime with pink haired girl escaping an asylum

Array or vector? Two dimensional array or matrix?

What does "spinning upon the shoals" mean?

NOLOCK or Read Uncommitted locking / latching behaviours

How do ballistic trajectories work in a ring world?

Why do airports remove/realign runways?

Update queryset on view without actually updating on database

How do I check whether a file exists without exceptions?How to combine 2 or more querysets in a Django view?How to print without newline or space?How do I do a not equal in Django queryset filtering?django - inlineformset_factory with more than one ForeignKeyShow information of subclass in list_display djangoProducts catalogue: filter by parametersRadio buttons in django adminLoop inside loop in queryset in Django templateHow to define Mode with generic ForeignKey in Django

.everyoneloves__top-leaderboard:empty,.everyoneloves__mid-leaderboard:empty,.everyoneloves__bot-mid-leaderboard:empty margin-bottom:0;

1

I'm trying to add a field "grade" to my users queryset. I have 3 models: Users, Subject and Exam. I don't think there is a way to calculate a user grade on the initial query like:

Users.objects.get(pk=x).annotate(grade=z)

because I have to call a method of the Subject model to calculate the total grade of that user for the subject, not only the grade for 1 exam (see the method below in the models description).

In my view I did:

user_obj = Users.object.get(pk=x).annotate(grade=Value(0, IntegerField()))
calculated_grade = subject.calculate_user_grade(user_obj)
user_obj.grade = calculated_grade

And then passed the user_obj to the template. But once it gets there the grade field I modified is already gone. I print "user_obj.grade" on view and it gives the correct value, then I print it on the template and it gives me 0, the initial value of the "annotate".

The models I use are the default user model in django and then

class Subject(models.Model):
 name = models.CharField()

 def calculate_user_grade(self, user):
 points = 0
 exams = Exam.objects.filter(subject=self)
 for exam in exams:
 user_answer = ExamUser.objects.get(user=user, exam=exam)
 points += user_answer.points
 return points

class Exam(models.Model):
 subject = models.ForeignKey(Subject)
 question = models.CharField()

class ExamUser(models.Model):
 exam = models.ForeignKey(Exam)
 user = models.ForeignKey(User)
 points = models.PositiveIntegerField(default=0)

python django django-queryset django-orm

share|improve this question

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do you pass the user_obj to the template? Can you show more of the view?
  
  – c6754
  Mar 25 at 21:34
  
  

  
  
  
  

add a comment | 

1

I'm trying to add a field "grade" to my users queryset. I have 3 models: Users, Subject and Exam. I don't think there is a way to calculate a user grade on the initial query like:

Users.objects.get(pk=x).annotate(grade=z)

because I have to call a method of the Subject model to calculate the total grade of that user for the subject, not only the grade for 1 exam (see the method below in the models description).

In my view I did:

user_obj = Users.object.get(pk=x).annotate(grade=Value(0, IntegerField()))
calculated_grade = subject.calculate_user_grade(user_obj)
user_obj.grade = calculated_grade

And then passed the user_obj to the template. But once it gets there the grade field I modified is already gone. I print "user_obj.grade" on view and it gives the correct value, then I print it on the template and it gives me 0, the initial value of the "annotate".

The models I use are the default user model in django and then

class Subject(models.Model):
 name = models.CharField()

 def calculate_user_grade(self, user):
 points = 0
 exams = Exam.objects.filter(subject=self)
 for exam in exams:
 user_answer = ExamUser.objects.get(user=user, exam=exam)
 points += user_answer.points
 return points

class Exam(models.Model):
 subject = models.ForeignKey(Subject)
 question = models.CharField()

class ExamUser(models.Model):
 exam = models.ForeignKey(Exam)
 user = models.ForeignKey(User)
 points = models.PositiveIntegerField(default=0)

python django django-queryset django-orm

share|improve this question

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  How do you pass the user_obj to the template? Can you show more of the view?
  
  – c6754
  Mar 25 at 21:34
  
  

  
  
  
  

add a comment | 

I'm trying to add a field "grade" to my users queryset. I have 3 models: Users, Subject and Exam. I don't think there is a way to calculate a user grade on the initial query like:

Users.objects.get(pk=x).annotate(grade=z)

because I have to call a method of the Subject model to calculate the total grade of that user for the subject, not only the grade for 1 exam (see the method below in the models description).

In my view I did:

user_obj = Users.object.get(pk=x).annotate(grade=Value(0, IntegerField()))
calculated_grade = subject.calculate_user_grade(user_obj)
user_obj.grade = calculated_grade

And then passed the user_obj to the template. But once it gets there the grade field I modified is already gone. I print "user_obj.grade" on view and it gives the correct value, then I print it on the template and it gives me 0, the initial value of the "annotate".

The models I use are the default user model in django and then

class Subject(models.Model):
 name = models.CharField()

 def calculate_user_grade(self, user):
 points = 0
 exams = Exam.objects.filter(subject=self)
 for exam in exams:
 user_answer = ExamUser.objects.get(user=user, exam=exam)
 points += user_answer.points
 return points

class Exam(models.Model):
 subject = models.ForeignKey(Subject)
 question = models.CharField()

class ExamUser(models.Model):
 exam = models.ForeignKey(Exam)
 user = models.ForeignKey(User)
 points = models.PositiveIntegerField(default=0)

python django django-queryset django-orm

share|improve this question

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

Users.objects.get(pk=x).annotate(grade=z)

user_obj = Users.object.get(pk=x).annotate(grade=Value(0, IntegerField()))
calculated_grade = subject.calculate_user_grade(user_obj)
user_obj.grade = calculated_grade

class Subject(models.Model):
 name = models.CharField()

 def calculate_user_grade(self, user):
 points = 0
 exams = Exam.objects.filter(subject=self)
 for exam in exams:
 user_answer = ExamUser.objects.get(user=user, exam=exam)
 points += user_answer.points
 return points

class Exam(models.Model):
 subject = models.ForeignKey(Subject)
 question = models.CharField()

class ExamUser(models.Model):
 exam = models.ForeignKey(Exam)
 user = models.ForeignKey(User)
 points = models.PositiveIntegerField(default=0)

share|improve this question

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

share|improve this question

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

edited Mar 26 at 2:38

tim

93199 silver badges3131 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

asked Mar 25 at 21:13

TomasRezendeTomasRezende

1622 bronze badges

1 Answer
1

active

oldest

votes

0

A good question. From your question and codes, the issues is probably from parsing the unsaved object from view to template.

The short answer is to use dictionary instead of parsing the unsaved object.

user_obj = Users.object.get(pk=x)
calculated_grade = subject.calculate_user_grade(user_obj)
user_dict = dict(user_obj)
user_dict.setdefault('grade', calculated_grade)

Then parse the user_dict to your template.

share|improve this answer

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

add a comment | 

Your Answer

StackExchange.ifUsing("editor", function ()
StackExchange.using("externalEditor", function ()
StackExchange.using("snippets", function ()
StackExchange.snippets.init();
);
);
, "code-snippets");

StackExchange.ready(function()
var channelOptions =
tags: "".split(" "),
id: "1"
;
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function()
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled)
StackExchange.using("snippets", function()
createEditor();
);

else
createEditor();

);

function createEditor()
StackExchange.prepareEditor(
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader:
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
,
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
);



);

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function ()
StackExchange.helpers.onClickDraftSave('#login-link');
);

Sign up using Google

Sign up using Facebook

Sign up using Email and Password

Post as a guest

Name

Email

Required, but never shown

StackExchange.ready(
function ()
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f55346492%2fupdate-queryset-on-view-without-actually-updating-on-database%23new-answer', 'question_page');

);

Post as a guest

Name

Email

Required, but never shown

0

A good question. From your question and codes, the issues is probably from parsing the unsaved object from view to template.

The short answer is to use dictionary instead of parsing the unsaved object.

user_obj = Users.object.get(pk=x)
calculated_grade = subject.calculate_user_grade(user_obj)
user_dict = dict(user_obj)
user_dict.setdefault('grade', calculated_grade)

Then parse the user_dict to your template.

share|improve this answer

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

add a comment | 

0

A good question. From your question and codes, the issues is probably from parsing the unsaved object from view to template.

The short answer is to use dictionary instead of parsing the unsaved object.

user_obj = Users.object.get(pk=x)
calculated_grade = subject.calculate_user_grade(user_obj)
user_dict = dict(user_obj)
user_dict.setdefault('grade', calculated_grade)

Then parse the user_dict to your template.

share|improve this answer

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

add a comment | 

A good question. From your question and codes, the issues is probably from parsing the unsaved object from view to template.

The short answer is to use dictionary instead of parsing the unsaved object.

user_obj = Users.object.get(pk=x)
calculated_grade = subject.calculate_user_grade(user_obj)
user_dict = dict(user_obj)
user_dict.setdefault('grade', calculated_grade)

Then parse the user_dict to your template.

share|improve this answer

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

user_obj = Users.object.get(pk=x)
calculated_grade = subject.calculate_user_grade(user_obj)
user_dict = dict(user_obj)
user_dict.setdefault('grade', calculated_grade)

share|improve this answer

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges

answered Mar 25 at 21:27

timtim

93199 silver badges3131 bronze badges