Save list of records and fields into django model

问题

I receive this list from my website admin:

[['present', '2'],['present', '1'], ['study', '1'], ['study', '3'], ['present', '4'], ['study', '4'], 

The first option is actually the field name that needs to be edit in Rollcall model and the second option is the user ID.

Now I want to save this list to the Rollcall model:

#models.py 
class Rollcall(models.Model):
    student = models.ForeignKey(User)
    present = models.BooleanField(default=False)
    study = models.BooleanField(default=False)

So I first check and find the various fields that a particular user has in the list, and then I will save all those fields for one user in my model. How can I do this?

--Update 1: this is HTML file:

{% forstudent in students %}
                            <tr>
                                <td>{{student}} </td>
                                <td> <input type="radio" name="present_{{student.id}}" value="1"></td>
                                <td> <input type="radio" name="study_{{student.id}}" value="1"></td>
                            </tr>
                        {% endfor %}

I get the data in this way and put them into the list that I explain in the first of this question:

data_list = [key.split('_') for key in request.POST.keys()][1:]

Each student can be present or absent or can study or not.my exactly question is: How can save data of all my student?Is there another way to solve this problem without data_list or any other way to create better data_list?

回答1:

Try something like this:

l=[['present', '2'], ['present', '3'], ['present', '4'], ['study', '2']]
dic={}
for arr in l:
    dic.setdefault(arr[1], []).append(arr[0])
for key in dic:
    Rollcall.objects.create(present=True if 'present' in dic[key] else False,\
    student=True if 'student' in dic[key] else False, \
    study=User.objects.get(id=int(key)))

or to make it in bulk after creating the dictionary (dic):

final_objects = [Rollcall(is_present=True if 'present' in final_dic[key] else False,
                          is_study=True if 'study' in final_dic[key] else False,
                          student=User.objects.get(id=int(key)),
                          ) for key in final_dic]
Rollcall.objects.bulk_create(final_objects)

回答2:

You can iterate over list, create Rollcall instances and use bulk_create() Manager/QuerySet method (This avoids a lot of database hits (Only one INSERT query will be enough) and gives you guarantee of atomicity).

data_list = [['present', '2'], ['present', '3'], ['present', '4'], ['study', '1']]

Rollcall.objects.bulk_create([
    Rollcall(present=True if present == 'present' else False, student_id=int(student_id)) for present, student_id in data_list)
])

Hope, it helps you.

来源：https://stackoverflow.com/questions/56310072/save-list-of-records-and-fields-into-django-model