I need to get a list containing all the users in a Many2many field, but I can't get the compute method to work.
Here's how my compute method looks by now :
def _get_all_employee_id(self):
for record in self:
record.employee_id = self.env['res.users'].search([('id', '=', 2)])
Here's how my field looks by now :
employee_id = fields.Many2many(comodel_name="res.users", string="Employé", compute='_get_all_employee_id', inverse_name='id', store=True)
This has no impact at all (wrote "('id', '=', 2)" to test my compute method, but I'd like to remove it, to get every user.).
It should be something like that.
partners = self.env['res.users'].search([])
record.employee_id = (6, 0, partners.ids)
I managed to overpass my problem yesterday.
Here's the final code :
employee_id = fields.Many2many(comodel_name="hr.employee", string="Employé", compute='_get_all_employee_id', store=True)
def _get_all_employee_id(self):
for record in self:
record.employee_id = self.env['hr.employee'].search([])
The inverse_name was the problem, and I think the compute method wasn't triggered some times...
Thank you to the ones who answered my post.
Related
Following the basic steps to create Prophet model and forecast
m = Prophet(daily_seasonality=True)
m.fit(data)
forecast = m.make_future_dataframe(periods=2)
forecast.tail().T
the result is as following (no yhat value ??)
The data passed in to fit the model has two columns (date and value).
Not sure what I have missed out here.
I managed to get it works by creating a new dataframe:
df_p = pd.DataFrame({'ds': d.index, 'y': d.values})
I've recently been tipped off to eager loading and its necessity in improving performance. I've managed to cut a few queries from loading this page, but I suspect that I can trim them down significantly more if I can eager-load the needed records correctly.
This controller needs to load all of the following to fill the view:
A Student
The seminar (class) page that the student is viewing
All of the objectives included in that seminar
The objective_seminars, the join table between objectives and seminars. This includes the column "priority" which is set by the teacher and used in ordering the objectives.
The objective_students, another join table. Includes a column "points" for the student's score on that objective.
The seminar_students, one last join table. Includes some settings that the student can adjust.
Controller:
def student_view
#student = Student.includes(:objective_students).find(params[:student])
#seminar = Seminar.includes(:objective_seminars).find(params[:id])
#oss = #seminar.objective_seminars.includes(:objective).order(:priority)
#objectives = #seminar.objectives.order(:name)
objective_ids = #objectives.map(&:id)
#student_scores = #student.objective_students.where(:objective_id => objective_ids)
#ss = #student.seminar_students.find_by(:seminar => #seminar)
#teacher = #seminar.user
#teach_options = teach_options(#student, #seminar, 5)
#learn_options = learn_options(#student, #seminar, 5)
end
The method below is where a lot of duplicate queries are occurring that I thought were supposed to be eliminated by eager loading. This method gives the student six options so she can choose one objective to teach her classmates. The method looks first at objectives where the student has scored between 75% and 99%. Within that bracket, they are also sorted by "priority" (from the objective_seminars join table. This value is set by the teacher.) If there is room for more, then the method looks at objectives where the student has scored 100%, sorted by priority. (The learn_options method is practically the same as this method, but with different bracket numbers.)
teach_options method:
def teach_options(student, seminar, list_limit)
teach_opt_array = []
[[70,99],[100,100]].each do |n|
#oss.each do |os|
obj = os.objective
this_score = #student_scores.find_by(:objective => obj)
if this_score
this_points = this_score.points
teach_opt_array.push(obj) if (this_points >= n[0] && this_points <= n[1])
end
end
break if teach_opt_array.length > list_limit
end
return teach_opt_array
end
Thank you in advance for any insight!
#jeff - In regards to your question, I don't see where a lot of queries would be happening outside of #student_scores.find_by(:objective => obj).
Your #student_scores object is already an ActiveRecord relation, correct? So you can use .where() on this, or .select{} without hitting the db again. Select will leave you with an array though, rather than an AR Relation, so be careful there.
this_score = #student_scores.where(objectve: obj)
this_score = #student_scores.select{|score| score.objective == obj}
Those should work.
Just some other suggestions on your top controller method - I don't see any guards or defensive coding, so if any of those objects are nil, your .order(:blah) is probably going to error out. Additionally, if they return nil, your subsequent queries which rely on their data could error out. I'd opt for some try()s or rescues.
Last, just being nitpicky, but those first two lines are a little hard to read, in that you could mistakenly interpret the params as being applied to the includes as well as the main object:
#student = Student.includes(:objective_students).find(params[:student])
#seminar = Seminar.includes(:objective_seminars).find(params[:id])
I'd put the find with your main object, followed by the includes:
#student = Student.find(params[:student]).includes(:objective_students)
#seminar = Seminar.find(params[:id]).includes(:objective_seminars)
I currently found out that you can hydrate an Raw sql query.
I have following query:
DB::table(DB::raw('(SELECT *, Y(location) AS longitude, X(location) AS latitude FROM meetings WHERE MBRCONTAINS(#quadrat, location)) AS sub'))
->select(DB::raw('(FLOOR(SQRT(POW((#ibk_breite - sub.latitude) * 111, 2) + POW((#ibk_laenge - sub.longitude) * 111 * ABS(COS(RADIANS(#ibk_breite))),2)))) AS distance, sub.*, latitude, longitude'));
which I hydrate as following
$meetings = Meeting::fromQuery($query->toSql());
In the blade view i need to get some additional data from different tables, for example:
$meeting->user
which references to the User Model. But if I'm not complety wrong that would result to a n+1 problem in a for each loop, because I'm not eager loading it?! So is it possible to eager load the required models as you would normally do with
->with('user', 'books', 'etc...')
??
Also is it possible to paginate it like $meetings = $query->paginate(5); and do $meetings->withPath('home');
EDIT:
Found a solution:
// Do your query stuff
// Get count before the query because it won't work with skip and take parameter
$count = $query->count();
$query->skip($skip);
$query->take($meetingsPerPage);
$meetings = Meeting::fromQuery($query->toSql());
$meetings->load('user', 'interest.image', 'img_thumbnail');
$meetings = new LengthAwarePaginator($meetings, $count, $meetingsPerPage);
$meetings->load acts as ->with().
As last step you need to create a paginator. IMPORTANT: Use query->count() before you set skip() and/or take() Otherwise it will not work.
Original answer from laracasts. Theres also another possibily stated that didn't work for me.
You can use setCollection() function with LengthAwarePaginator object (found in Illuminate/Pagination/AbstractPaginator.php). Use load() for eager loading.
$users = DB::table('users')->paginate();
$users->setCollection(User::hydrate($users->items())->load(['category']));
My solution:
// Do your query stuff
// Get count before the query because it won't work with skip and take parameter
$count = $query->count();
$query->skip($skip);
$query->take($meetingsPerPage);
$meetings = Meeting::fromQuery($query->toSql());
$meetings->load('user', 'interest.image', 'img_thumbnail');
$meetings = new LengthAwarePaginator($meetings, $count, $meetingsPerPage);
$meetings->load acts as ->with(). As last step you need to create a paginator. IMPORTANT: Use query->count() before you set skip() and/or take() Otherwise it will not work.
Original answer from laracasts. Theres also another possibily stated that didn't work for me.
I'd like to update a table with Django - something like this in raw SQL:
update tbl_name set name = 'foo' where name = 'bar'
My first result is something like this - but that's nasty, isn't it?
list = ModelClass.objects.filter(name = 'bar')
for obj in list:
obj.name = 'foo'
obj.save()
Is there a more elegant way?
Update:
Django 2.2 version now has a bulk_update.
Old answer:
Refer to the following django documentation section
Updating multiple objects at once
In short you should be able to use:
ModelClass.objects.filter(name='bar').update(name="foo")
You can also use F objects to do things like incrementing rows:
from django.db.models import F
Entry.objects.all().update(n_pingbacks=F('n_pingbacks') + 1)
See the documentation.
However, note that:
This won't use ModelClass.save method (so if you have some logic inside it won't be triggered).
No django signals will be emitted.
You can't perform an .update() on a sliced QuerySet, it must be on an original QuerySet so you'll need to lean on the .filter() and .exclude() methods.
Consider using django-bulk-update found here on GitHub.
Install: pip install django-bulk-update
Implement: (code taken directly from projects ReadMe file)
from bulk_update.helper import bulk_update
random_names = ['Walter', 'The Dude', 'Donny', 'Jesus']
people = Person.objects.all()
for person in people:
r = random.randrange(4)
person.name = random_names[r]
bulk_update(people) # updates all columns using the default db
Update: As Marc points out in the comments this is not suitable for updating thousands of rows at once. Though it is suitable for smaller batches 10's to 100's. The size of the batch that is right for you depends on your CPU and query complexity. This tool is more like a wheel barrow than a dump truck.
Django 2.2 version now has a bulk_update method (release notes).
https://docs.djangoproject.com/en/stable/ref/models/querysets/#bulk-update
Example:
# get a pk: record dictionary of existing records
updates = YourModel.objects.filter(...).in_bulk()
....
# do something with the updates dict
....
if hasattr(YourModel.objects, 'bulk_update') and updates:
# Use the new method
YourModel.objects.bulk_update(updates.values(), [list the fields to update], batch_size=100)
else:
# The old & slow way
with transaction.atomic():
for obj in updates.values():
obj.save(update_fields=[list the fields to update])
If you want to set the same value on a collection of rows, you can use the update() method combined with any query term to update all rows in one query:
some_list = ModelClass.objects.filter(some condition).values('id')
ModelClass.objects.filter(pk__in=some_list).update(foo=bar)
If you want to update a collection of rows with different values depending on some condition, you can in best case batch the updates according to values. Let's say you have 1000 rows where you want to set a column to one of X values, then you could prepare the batches beforehand and then only run X update-queries (each essentially having the form of the first example above) + the initial SELECT-query.
If every row requires a unique value there is no way to avoid one query per update. Perhaps look into other architectures like CQRS/Event sourcing if you need performance in this latter case.
Here is a useful content which i found in internet regarding the above question
https://www.sankalpjonna.com/learn-django/running-a-bulk-update-with-django
The inefficient way
model_qs= ModelClass.objects.filter(name = 'bar')
for obj in model_qs:
obj.name = 'foo'
obj.save()
The efficient way
ModelClass.objects.filter(name = 'bar').update(name="foo") # for single value 'foo' or add loop
Using bulk_update
update_list = []
model_qs= ModelClass.objects.filter(name = 'bar')
for model_obj in model_qs:
model_obj.name = "foo" # Or what ever the value is for simplicty im providing foo only
update_list.append(model_obj)
ModelClass.objects.bulk_update(update_list,['name'])
Using an atomic transaction
from django.db import transaction
with transaction.atomic():
model_qs = ModelClass.objects.filter(name = 'bar')
for obj in model_qs:
ModelClass.objects.filter(name = 'bar').update(name="foo")
Any Up Votes ? Thanks in advance : Thank you for keep an attention ;)
To update with same value we can simply use this
ModelClass.objects.filter(name = 'bar').update(name='foo')
To update with different values
ob_list = ModelClass.objects.filter(name = 'bar')
obj_to_be_update = []
for obj in obj_list:
obj.name = "Dear "+obj.name
obj_to_be_update.append(obj)
ModelClass.objects.bulk_update(obj_to_be_update, ['name'], batch_size=1000)
It won't trigger save signal every time instead we keep all the objects to be updated on the list and trigger update signal at once.
IT returns number of objects are updated in table.
update_counts = ModelClass.objects.filter(name='bar').update(name="foo")
You can refer this link to get more information on bulk update and create.
Bulk update and Create
I've been trying very hard to get this working but so far haven't found the correct route.
I am using pyqt, and I am querying a MySql DataBase, collecting from it a model with all the columns. Until here it's all good..
I've created a combobox that is displaying the correct text using model.setcolumn(1)
What I need now is for this combobox to send on "activated" the relative unique ID of this record, so I am able to create a category relatioship.
What exactly is the best way to do this? I feel I've arrived to a dead end, any help would be appreciated.
Best,
Cris
Best way would be sub-classing QComboBox. You can't override the activated signal but you can create a custom signal that will also be emitted with ID whenever activated is emitted. And you can connect to this signal and do your stuff. It will be something like this:
class MyComboBox(QtGui.QComboBox):
activatedId = QtCore.pyqtSignal(int) #correct this if your ID is not an int
def __init__(self, parent=None):
super(MyComboBox, self).__init__(parent)
self.activated.connect(self.sendId)
#QtCore.pyqtSlot(int)
def sendId(self, index):
model = self.model()
uniqueIdColumn = 0 # if ID is elsewhere adjust
uniqueId = model.data(model.createIndex(index,uniqueIdColumn,0),QtCore.Qt.DisplayRole)
self.activatedId.emit(uniqueId)
Edit
Here is a similar version without Signals. This will return uniqueId whenever you call sendId with an index of the combobox.
class MyComboBox(QtGui.QComboBox):
def __init__(self, parent=None):
super(MyComboBox, self).__init__(parent)
def sendId(self, index):
model = self.model()
uniqueIdColumn = 0 # if ID is elsewhere adjust
uniqueId = model.data(model.createIndex(index,uniqueIdColumn,0),QtCore.Qt.DisplayRole)
return uniqueId