Update set of fields in django model passed in request.POST - django

Question

This is my Model class
class SubJobs(models.Model):
id = models.AutoField(primary_key = True)
subjob_name = models.CharField(max_length=32,help_text="Enter subjob name")
subjobtype = models.ForeignKey(SubjobType)
jobstatus = models.ForeignKey(JobStatus, default= None, null=True)
rerun = models.ForeignKey(ReRun,help_text="Rerun")
transfer_method = models.ForeignKey(TransferMethod,help_text="Select transfer method")
priority = models.ForeignKey(Priority,help_text="Select priority")
suitefiles = models.ForeignKey(SuiteFiles,help_text="Suite file",default=None,null=True)
topofiles = models.ForeignKey(TopoFiles,help_text="Topo file",default=None,null=True)
load_image = models.NullBooleanField(default = True,help_text="Load image")
description = models.TextField(help_text="Enter description",null=True) command = models.TextField(help_text="Command",null=True)
run_id = models.IntegerField(help_text="run_id",null=True)
pid_of_run = models.IntegerField(help_text="pid_of_run",null=True)
hold_time = models.IntegerField()
created = models.DateTimeField(default=timezone.now,null=True)
updated = models.DateTimeField(default=timezone.now,null=True)
finished = models.DateTimeField(null=True)
The user might want to update a entry and may choose to update only few fields among these. How do I write a generic update statement that would update only the fields that were passed?
I tried this.
def update_subjob(request):
if (request.method == 'POST'):
subjobs_subjobid = request.POST[('subjob_id')]
post_data = request.POST
if 'subjob_name' in post_data:
subjobs_subjobname = request.POST[('subjob_name')]
if 'subjob_type' in post_data:
subjobs_subjobtype = request.POST[('subjob_type')]
if 'rerun_id' in post_data:
subjobs_rerun_id = request.POST[('rerun_id')]
if 'priority_id' in post_data:
subjobs_priority_id = request.POST[('priority_id')]
if 'transfer_method' in post_data:
subjobs_transfermethod = request.POST[('transfer_method')]
if 'suitefile' in post_data:
subjob_suitefile = request.POST[('suitefile')]
if 'topofile' in post_data:
subjob_topofile = request.POST[('topofile')]
try:
subjobinstance = SubJobs.objects.filter(id=subjobs_subjobid).update(subjob_name=subjobs_subjobname,
updated=datetime.now())
except Exception as e:
print("PROBLEM UPDAING SubJob!!!!")
print(e.message)
How do I write a generic update to update only those fields which are sent in request.POST?

Answer 1

You'd better use Forms. But if you insist on your code it could be done like this.
Suppose you have variable field_to_update where every field that you are waiting in request is listed.
subjobs_subjobid = request.POST[('subjob_id')]
field_to_update = ('subjob_name','subjob_type', 'rerun_id', 'priority_id', 'transfer_method', 'suitefile', 'topofile')
post_data = request.POST
to_be_updated = {field: post_data.get(field) for field in field_to_update if field in post_data}
# then you need to get the object, not filter it
try:
subjobinstance = SubJobs.objects.get(id=subjobs_subjobid)
subjobinstance.update(**to_be_updated, updated=datetime.now())
except ObjectDoesNotExist: # from django.core.exceptions
print('There is no such object') # better to use logger
except Exception as e:
print("PROBLEM UPDAING SubJob!!!!")
print(e.message)