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Мои запросы приложения hodgepodge идут дальше моего знания того, как работает ORM от Django.Сложный запрос Django
Вот моя текущая (неправильная) попытка:
queryset = Mentor.objects.filter(
shift__session = session,
jobs_desired = job
).exclude(
shift__session = session,
shift__jobs__time = job.time
)
Мои модели ниже, если вы хотите, чтобы прочитать их.
Начальный filter() отлично работает. Моя проблема - exclude(), прикованный к концу.
exclude(), как представляется, за исключением Mentor с с:
- ассоциированным
Shiftкоторый удовлетворяет условиям, указанным (shift__session = session), - И (возможно другое), связанного
Shift, что соответствует второй набор критерииshift__jobs__time = job.time.
Я только хочу, чтобы отфильтровать Mentor S, которые имеют Shift, связанные с ними, что соответствует ОБА критерию.
Любые идеи?
class DojoSession(models.Model):
term = models.ForeignKey(DojoTerm, help_text = "Dojo Term")
date = models.DateField(
blank = False,
help_text = "Date during which the session will take place."
)
start = models.TimeField(
blank = False,
help_text = "Start Time"
)
end = models.TimeField(
blank = False,
help_text = "End Time"
)
rooms = models.ManyToManyField(
Room,
blank = True,
help_text = "The rooms in which this session will be running."
)
class Shift(models.Model):
mentor = models.ForeignKey(
'mentors.Mentor',
blank = False,
help_text = 'The mentor unergoing this shift.'
)
session = models.ForeignKey(
DojoSession,
blank = False,
help_text = 'The session during which this shift takes place.',
)
role = models.ForeignKey(
'mentors.Role',
blank = False,
help_text = "The role that the mentor will be undertaking during this shift.",
)
room = models.ForeignKey(
Room,
blank = True,
null = True,
help_text = "The room, if any, that the mentor will be undertaking the shift in."
)
jobs = models.ManyToManyField(
'jobs.Job',
blank = True,
null = True,
)
start = models.TimeField(
blank = False,
help_text = "Start Time"
)
end = models.TimeField(
blank = False,
help_text = "End Time"
)
class Job(models.Model):
BEFORE = 'B'
DURING = 'D'
AFTER = 'A'
TIME_CHOICES = (
(BEFORE, 'Before session'),
(DURING, 'During session'),
(AFTER, 'After session'),
)
name = models.CharField(
max_length = 50,
help_text = "The job's name."
)
description = models.TextField(
max_length = 1024,
help_text = "A description of the job."
)
location = models.CharField(
max_length = 50,
help_text = "The job's location."
)
time = models.CharField(
max_length = 1,
choices = TIME_CHOICES,
help_text = "The time during a session at which this job can be carried out."
)
class Mentor(models.Model):
MALE_SMALL = "MS"
MALE_MEDIUM = "MM"
MALE_LARGE = "ML"
MALE_EXTRA_LARGE = "MXL"
FEMALE_EXTRA_SMALL = "FXS"
FEMALE_SMALL = "FS"
FEMALE_MEDIUM = "FM"
FEMALE_LARGE = "FL"
FEMALE_EXTRA_LARGE = "FXL"
SHIRT_SIZE_CHOICES = (
('Male', (
(MALE_SMALL, "Male S"),
(MALE_MEDIUM, "Male M"),
(MALE_LARGE, "Male L"),
(MALE_EXTRA_LARGE, "Male XL")
)),
('Female', (
(FEMALE_EXTRA_SMALL, "Female XS"),
(FEMALE_SMALL, "Female S"),
(FEMALE_MEDIUM, "Female M"),
(FEMALE_LARGE, "Female L"),
(FEMALE_EXTRA_LARGE, "Female XL")
))
)
ASSOCIATE = 'A'
STAFF = 'S'
NEITHER = 'N'
CURTIN_STATUS_CHOICES = (
(ASSOCIATE, 'Associate'),
(STAFF, 'Staff'),
(NEITHER, 'Neither/not sure')
)
NOTHING = 'NO'
SOMETHING = 'SO'
EVERYTHING = 'EV'
KNOWLEDGE_CHOICES = (
(NOTHING, 'I know nothing but am keen to learn!'),
(SOMETHING, 'I know some basics'),
(EVERYTHING, 'I know a great deal')
)
uni = models.CharField(
max_length = 50,
null = True,
blank = True,
help_text = "University of study"
)
uni_study = models.CharField(
max_length = 256,
null = True,
blank = True,
help_text = "If you're attending university, what are you studying?"
)
work = models.CharField(
max_length = 256,
null = True,
blank = True,
help_text = "If you workwhat do you do?"
)
shirt_size = models.CharField(
max_length = 3,
blank = True,
choices = SHIRT_SIZE_CHOICES,
help_text = "T-shirt size (for uniform)"
)
needs_shirt = models.BooleanField(
default = True,
help_text = "Does the mentor need to have a shirt provisioned for them?"
)
wwcc = models.CharField(
max_length = 10,
verbose_name = "WWCC card number",
blank = True,
null = True,
help_text = "WWCC card number (if WWCC card holder)"
)
wwcc_receipt = models.CharField(
max_length = 15,
verbose_name = "WWCC receipt number",
blank = True,
null = True,
help_text = "WWCC receipt number (if WWCC is processing)"
)
curtin_status = models.CharField(
max_length = 1,
verbose_name = "Current Curtin HR status",
choices = CURTIN_STATUS_CHOICES,
default = NEITHER,
blank = False,
help_text = "When possible, we recommend that all CoderDojo mentors are either Curtin University Associates or Staff members."
)
curtin_id = models.CharField(
max_length = 10,
verbose_name = "Curtin Staff/Associate ID",
blank = True,
null = True,
help_text = "Your Curtin Staff/Associate ID (if applicable)"
)
coding_experience = models.CharField(
max_length = 2,
blank = False,
default = NOTHING,
choices = KNOWLEDGE_CHOICES,
help_text = "How much programming experience do you have?"
)
children_experience = models.CharField(
max_length = 2,
blank = False,
default = NOTHING,
choices = KNOWLEDGE_CHOICES,
help_text = "How much experience do you have with children?"
)
roles_desired = models.ManyToManyField(Role)
jobs_desired = models.ManyToManyField('jobs.Job')
shift_availabilities = models.ManyToManyField(
'planner.DojoSession',
help_text = "When are you available?"
)
user = models.OneToOneField(settings.AUTH_USER_MODEL,
unique = True
)
Я прочитал Ответ на этот вопрос несколько раз, насколько я могу сказать, что я делаю смысл этого, но я с трудом связав его с фактическим запросом, который мне потребуется. Опять же, может быть, я только начал использовать Django, и мне сложно сопоставить, что 'exclude()' (или 'filter()', если на то пошло) делает для реального SQL. Буду признателен за измененный запрос, если возможно :) Спасибо за вашу помощь. –
Обновлен с полным ответом! –
Ха-ха, теперь я чувствую себя глупо. Огромное спасибо. Я сделаю это. –