I have a query as below which returns the grade of all students of a specific class in a specific term(semester) in a specific session(academic year):
grades = Grade.objects.filter(term='First', student__in_class=1,session=1).order_by('-total')
then another query that annotate through the grades in order to get the sum of the 'total' field.
grades_ordered = grades.values('student')\
.annotate(total_mark=Sum('total')) \
.order_by('-total_mark')
At first everything works fine until when i migrated from using SQLite to postgreSQL then the following error begins to show up.
ERROR:
function sum(character varying) does not exist
LINE 1: SELECT "sms_grade"."student_id", SUM("sms_grade"."total") AS...
^
HINT: No function matches the given name and argument types. You might need to add explicit type casts.
EDIT:
here is my model
class Grade(models.Model):
session = models.ForeignKey(Session, on_delete=models.CASCADE)
term = models.CharField(choices=TERM, max_length=7)
student = models.ForeignKey(Student, on_delete=models.CASCADE)
subject = models.ForeignKey(Subject, on_delete=models.CASCADE)
fca = models.CharField(max_length=10)
sca = models.CharField(max_length=10)
exam = models.CharField(max_length=10)
total = models.CharField(max_length=3, blank=True, null=True)
grade = models.CharField(choices=GRADE, max_length=1, blank=True, null=True)
remark = models.CharField(max_length=50, blank=True, null=True)
any help you can provide would be appreciated.
thanks
Store numbers in integer or decimal not in text/varchar field
total = models.Integer(max_length=3, blank=True, null=True)
see this link
also read this
Related
I have a model Allotment
class Kit(models.Model):
kit_types = (('FLC', 'FLC'), ('FSC', 'FSC'), ('Crate', 'Crate'), ('PP Box', 'PP Box'))
kit_name = models.CharField(max_length=500, default=0)
kit_type = models.CharField(max_length=50, default=0, choices=kit_types, blank=True, null=True)
class AllotmentFlow(models.Model):
flow = models.ForeignKey(Flow, on_delete=models.CASCADE)
kit = models.ForeignKey(Kit, on_delete=models.CASCADE)
asked_quantity = models.IntegerField(default=0)
alloted_quantity = models.IntegerField(default=0)
class Allotment(models.Model):
transaction_no = models.IntegerField(default=0)
dispatch_date = models.DateTimeField(default=datetime.now)
send_from_warehouse = models.ForeignKey(Warehouse, on_delete=models.CASCADE)
flows = models.ManyToManyField(AllotmentFlow)
For a stacked graph I am trying to get the data of different kit_type alloted in different months.
For that I have tried annotate but it isn't getting the desired results
dataset = Allotment.objects.all().annotate(
month=TruncMonth('dispatch_date')).values(
'month').annotate(dcount=Count('flows__kit__kit_type')).values('month', 'dcount')
Expected Output:
[{'month':xyz, 'kit_type':foo, count:123},...]
I am getting the month and count of kit type from above but how do I segregate it by kit_type?
having a field that represents your choice field names in this query is difficult
instead how about use the Count filter argument and annotate to get what you want
dataset = Allotment.objects.all().annotate(month=TruncMonth('dispatch_date')).values('month').annotate(
FLC_count=Count('flows__kit__kit_type', filter=Q(flows__kit__kit_type="FLC")),
FSC_count=Count('flows__kit__kit_type', filter=Q(flows__kit__kit_type="FSC")),
Crate_count=Count('flows__kit__kit_type', filter=Q(flows__kit__kit_type="Crate")),
PP_Box_count=Count('flows__kit__kit_type', filter=Q(flows__kit__kit_type="PP_Box")),
).values('month', 'FLC_count', 'FSC_count', 'Crate_count', 'PP_Box_count')
I have the following working SQL statement:
SELECT id FROM ops_kpitarget WHERE (site_id = 1 AND validFrom <= "2019-08-28") GROUP BY kpi_id HAVING validFrom = (MAX(validFrom))
But I cannot get this to work inside Django ORM.
The best I got was the code below, but then the database is complaining that it is missing a GROUP BY clause to make HAVING work.
How can I get the same query with specifying "kpi_id" as the GROUP BY clause using Djangos ORM? Any ideas?
KpiTarget.objects
.filter(validFrom__lte=fromDate)
.values("id", "kpi")
.filter(validFrom=Max("validFrom"))
... which translates to:
SELECT "ops_kpitarget"."id", "ops_kpitarget"."kpi_id" FROM "ops_kpitarget" WHERE "ops_kpitarget"."validFrom" <= 2019-08-14 HAVING "ops_kpitarget"."validFrom" = (MAX("ops_kpitarget"."validFrom"))
I played around with annotate but this is not really giving me what I want...
Update:
Some background: I have 3 tables: Kpi, KpiTarget, and KpiTargetObservation.
Kpi holds all general information regarding the KPI like name, typeetc.
KpiTarget stores target values defined for several different sites. These target values can change over time. Hence, I have included the combination of MAX() and validFrom <= (some date) to determine the latest valid target for any given KPI.
KpiTargetObservation stores the individual observations per defined KPI target. It just holds the link to KpiTarget, the date of the observation, and the observation value.
The final queries I need to build will have to give me something like the following:
give me all known KPIs per given site
tell me the most recent target value for the KPIs you found
get me any known observation that is related to the identified kpi targets
I am struggling with the 2nd query, and specifically how to get this working using Djangos ORM. I could just escape to RAW SQL, but I would prefer to not to, if possible.
The models:
class KpiCategory(models.Model):
name = models.CharField(max_length=255)
def __str__(self):
return self.name
class Kpi(models.Model):
KPI_KIND_CHOICES = [("BOOL", "Boolean"), ("FLOAT", "Float"), ("STRING", "String")]
# firstCreated = models.DateField(auto_now_add=True)
# firstCreatedBy = models.OneToOneField(User, on_delete=models.CASCADE)
# lastEdited = models.DateField(auto_now=True)
# lastEditedBy = models.OneToOneField(User, on_delete=models.CASCADE)
name = models.CharField(max_length=255)
category = models.ForeignKey(KpiCategory, on_delete=models.CASCADE)
kind = models.CharField(max_length=150, choices=KPI_KIND_CHOICES)
def __str__(self):
return self.name
class KpiTarget(models.Model):
# firstCreated = models.DateField(auto_now_add=True)
# firstCreatedBy = models.OneToOneField(User, on_delete=models.CASCADE)
# lastEdited = models.DateField(auto_now=True)
# lastEditedBy = models.OneToOneField(User, on_delete=models.CASCADE)
kpi = models.ForeignKey(Kpi, on_delete=models.CASCADE, related_name="kpiTargetSet")
targetDouble = models.DecimalField(
max_digits=20, decimal_places=15, blank=True, null=True
)
targetBool = models.BooleanField(blank=True, null=True)
targetStr = models.CharField(max_length=255, blank=True)
site = models.ForeignKey(Site, on_delete=models.CASCADE)
validFrom = models.DateField()
def __str__(self):
return str(self.kpi)
class KpiObservation(models.Model):
# firstCreated = models.DateField(auto_now_add=True)
# firstCreatedBy = models.OneToOneField(User, on_delete=models.CASCADE)
# lastEdited = models.DateField(auto_now=True)
# lastEditedBy = models.OneToOneField(User, on_delete=models.CASCADE)
kpiTarget = models.ForeignKey(
KpiTarget, on_delete=models.CASCADE, related_name="kpiObservationSet"
)
observed = models.DateField()
observationDouble = models.DecimalField(
max_digits=20, decimal_places=15, blank=True, null=True
)
observationBool = models.BooleanField(blank=True, null=True)
observationStr = models.CharField(max_length=255, blank=True)
def __str__(self):
return str(self.observed)
KpiTarget.objects.filter(validFrom__lte=fromDate).annotate(validFrom=Max("validFrom")).order_by('kpi__id').values("id", "kpi")
Django newbie, so if this is super straightfoward I apologize.
I am attempting to get a listing of distinct "Name" values from a listing of "Activity"s for a given "Person".
Models setup as below
class Activity(models.Model):
Visit = models.ForeignKey(Visit)
Person = models.ForeignKey(Person)
Provider = models.ForeignKey(Provider)
ActivityType = models.ForeignKey(ActivityType)
Time_Spent = models.IntegerField(blank=True, null=True)
Repetitions = models.CharField(max_length=20, blank=True, null=True)
Weight_Resistance = models.CharField(max_length=50, blank=True, null=True)
Notes = models.CharField(max_length=500, blank=True, null=True)
class ActivityType(models.Model):
Name = models.CharField(max_length=100)
Activity_Category = models.CharField(max_length=40, choices=Activity_Category_Choices)
Location_Category = models.CharField(max_length=30, blank=True, null=True, choices=Location_Category_Choices)
I can get a listing of all activities done with a given Person
person = Person.objects.get(id=person_id)
activity_list = person.activity_set.all()
I get a list of all activities for that person, no problem.
What I can't sort out is how to generate a list of distinct/unique Activity_Types found in person.activity_set.all()
person.activity_set.values('ActivityType').distinct()
only returns a dictionary with
{'ActivityType':<activitytype.id>}
I can't sort out how to get straight to the name attribute on ActivityType
This is pretty straightforward in plain ol' SQL, so I know my lack of groking the ORM is to blame.
Thanks.
Update: I have this working, sort of, but this CAN'T be the right way(tm) to do this..
distinct_activities = person.activity_set.values('ActivityType').distinct()
uniquelist = []
for x in distinct_activities:
valuetofind = x['ActivityType']
activitytype = ActivityType.objects.get(id=valuetofind)
name = activitytype.Name
uniquelist.append((valuetofind, name))
And then iterate over that uniquelist...
This has to be wrong...
unique_names = ActivityType.objects.filter(
id__in=Activity.objects.filter(person=your_person).values_list('ActivityType__id', flat=True).distinct().values_list('Name', flat=True).distinct()
This should do the trick. There will be not a lot of db hits also.
Writing that down from my phone, so care for typos.
Among my models, I have Exercise which has a m2m link to Workout. I also have WorkoutPlan and LogBook which are types of Workouts. WorkoutPlan is where ideal workouts are stored. LogBook is where a user stores the workout they actually completed. They can also link a LogBook to a WorkoutPlan to indicate that the actual performance was connected to an original ideal plan.
class Exercise(NameDescModel):
muscles = models.ManyToManyField(Muscle, blank=True)
groups = models.ManyToManyField(Group, blank=True)
priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0)
frequency = models.IntegerField()
time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK)
last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now)
class Workout(NameDescModel):
exericises = models.ManyToManyField(Exercise, through='Measurement')
class WorkoutPlan(Workout):
priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0)
frequency = models.IntegerField()
time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK)
time_estimate = models.IntegerField()
last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now)
class LogBook(Workout):
workout_date = models.DateField(default=datetime.now)
notes = models.TextField(blank=True)
workout_plan = models.ForeignKey(WorkoutPlan, blank=True, null=True)
For a given exercise, I want to pull all of the WorkoutPlans that the exercise is in.
exercise_list = Exercise.objects.order_by('-last_p_calc_date')
for exercise in exercise_list:
print exercise
workout_list = []
for workout in exercise.workout_set.all():
workout_list.append(workout)
print list(set(workout_list))
print ""
I'm realizing that the list of workouts include both WorkoutPlans and LogBooks because exercise is attached to Workout, not to WorkoutPlans or LogBooks specifically.
How might I pull Workouts that are affiliated only to WorkoutPlans?
I think you've over-used inheritance here.
I guess you wanted to put the exercises field into a base model because WorkoutPlan and LogBook both have that field. But it seems like in reality WorkoutPlan and LogBook are different types of thing, rather than sub-types of Workout.
Possibly don't you need the exercises field on the LogBook model at all, since it has a foreign key to WorkoutPlan which seems a sensible place to record the exercises... unless you want to record the difference between the plan and exercises actually performed?
I would model it like this:
class Exercise(NameDescModel):
muscles = models.ManyToManyField(Muscle, blank=True)
groups = models.ManyToManyField(Group, blank=True)
priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0)
frequency = models.IntegerField()
time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK)
last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now)
class WorkoutPlan(Workout):
exercises = models.ManyToManyField(Exercise, through='Measurement')
priority_score = models.DecimalField(max_digits=5, decimal_places=3, editable=False, default = 0)
frequency = models.IntegerField()
time_period = models.CharField(max_length=2, choices=TIME_PERIOD_CHOICES,default=WEEK)
time_estimate = models.IntegerField()
last_p_calc_date = models.DateField("Date of Last Priority Recalculation", blank=True, null=True, default=datetime.now)
class LogBook(Workout):
exercises = models.ManyToManyField(Exercise, through='Measurement')
workout_date = models.DateField(default=datetime.now)
notes = models.TextField(blank=True)
workout_plan = models.ForeignKey(WorkoutPlan, blank=True, null=True)
You can then query either WorkoutPlans or LogBooks from an Exercise instance:
exercise_list = Exercise.objects.order_by('-last_p_calc_date')
for exercise in exercise_list:
print exercise
workout_list = exercise.workoutplan_set.all()
print ""
I am currently building a page in django, where there are 4 form fields, 2 text, 2 select fields, and when submitted it takes those fields and searches several models for matchinng items.
the model looks like this:
class Person(models.Model):
user = models.ForeignKey(User, blank=True, null=True, verbose_name="the user associated with this profile")
first_name = models.CharField(max_length=255)
last_name = models.CharField(max_length=255)
about = models.TextField(max_length=255, blank=True, null=True)
birthdate = models.DateField(blank=True, null=True, verbose_name="Birthdate (yyyy-mm-dd)")
GENDER_CHOICES = (
(u'M', u'Male'),
(u'F', u'Female'),
)
gender = models.CharField(max_length=1, choices = GENDER_CHOICES, default = 'M')
picture = models.ImageField(upload_to='profile', blank=True, null=True)
nationality = CountryField(blank=True, null=True)
location = models.CharField(max_length=255, blank=True, null=True)
command_cert = models.BooleanField(verbose_name="COMMAND certification")
experience = models.ManyToManyField('userProfile.MartialArt', blank=True, null=True)
and I am trying to search the first_name field, the last_name field, the nationality field, and the experience field, but say if the first_name field is blank, I need to pass an empty value so it returns all rows, then filter from there with last name the same way, for some reason it is not working at all for me. this is my sqs:
results = SearchQuerySet().models(Person).filter(first_name=sname, last_name=slastname, nationality=scountry, experience__pk=sexperience)
any ideas?
Without seeing specific errors or a stack trace, it's hard to determine what "is not working at all".
Edit: Looking at your provided view code, I would remove the filter and return all of the objects for your Fighter, Referee, Insider, and Judge models. This is to ensure that the issue here lies in the filter, and not something else.
Then, once I'd verified that objects are being placed into results, I'd put in the filters one at a time to determine what the problematic filter is. Give this a try and reply back with your results.