I want to combine (|) a series of QuerySets:all_english_text in a loop:
tag_result = Tag.objects.get(id=all_tag[index])
all_english_text = tag_result.notes.all().values('english_text', 'id')
by the following def:
def list_by_tag_post(request):
# get POST
all_tag = request.POST.getlist('tag_list')
for index in range(len(all_tag)):
tag_result = Tag.objects.get(id=all_tag[index])
all_english_text = tag_result.notes.all().values('english_text', 'id')
result = list(chain(*all_english_text)) # Merging method
all_english_text = result
# to template
context = {'all_english_text': all_english_text, 'all_tag': all_tag}
return render(request, 'list_by_tag.html', context)
3 methods were tried, they all didn't work:
result = list(chain(*all_english_text)) # Merging method 1
result = chain(*all_english_text) # Merging method 2
result = all_english_text.union(*all_english_text))# Merging method 3
This should be possible in a single query.
Without knowing what Tag.notes is it may not be exactly right. I'm assuming it's a reverse relationship from a ForeignKey on a Note model (Note.tag)
all_english_text = Note.objects.filter(tag_id__in=all_tag).values('english_text', 'id')
Related
I have two query sets to get the values for stock_in and stock_out. How do i loop to subtract stock_out from stock_in
here are the querysets
stock_in = OrderItems.objects.values('drug').annotate(
quantity_received=Sum('quantity_received'),
).order_by('drug')
stock_out = RequestItems.objects.values('drug').annotate(
quantity_received=Sum('quantity_issued')
).order_by('drug')
Approach it from the Drug model. It makes it a bit easier on the query.
Drug.objects.annotate(
stock_in=Sum('orderitems_set__quantity_received'),
stock_out=Sum('requestitems_set__quantity_issued'),
).annotate(
current_stock=F('stock_in')-F('stock_out')
)
Or you might be able to do it in one. I'm not sure.
Drug.objects.annotate(
current_stock=Sum('orderitems_set__quantity_received') - Sum('requestitems_set__quantity_issued'),
)
def stock_list(request):
stock_in = OrderItems.objects.values('drug__drugTitle','drug__drugCode', 'drug__denom_quantity').order_by('drug').annotate(quant_in=Sum('quantity_received'))
stock_out = RequestItems.objects.values('drug__drugTitle', 'drug__drugCode', 'drug__denom_quantity').order_by('drug').annotate(quant_out=Sum('quantity_issued'))
stock_available=[]
index = 0
for item in stock_out:
if item is None:
remaining_stc = stock_in[index]['quant_in']
stock_available.append({'drug__drugTitle':stock_in[index]['drug__drugTitle'],'drug__drugCode':stock_in[index]['drug__drugCode'], 'drug__denom_quantity':stock_in[index]['drug__denom_quantity'], 'quantr':remaining_stc})
else:
remaining_stc = stock_in[index]['quant_in']-stock_out[index]['quant_out']
stock_available.append({'drug__drugTitle':stock_in[index]['drug__drugTitle'],'drug__drugCode':stock_in[index]['drug__drugCode'], 'drug__denom_quantity':stock_in[index]['drug__denom_quantity'], 'quantr':remaining_stc})
index = index + 1
context = {
"stock_available":stock_available,
}
return render(request, 'stock/stock_list.html', context)
I'm trying to create a list which consists of several calculations. next, the idea is to render it in a template.
This is what I have so far:
views.py :
def calculation(request, itemslug):
#All the Values ordered chronologically:
values = Value.objects.filter(item__slug=itemslug).order_by('date')
dates = []
results =[]
#Create a list consisting of the dates
for value in values:
a = value.date
dates.append(a)
#Peform a calculation per date
for date in dates:
latestvalue = Value.objects.filter(item__slug=itemslug).get(date=date)['amount']
paidup = CashFlow.objects.filter(item__slug=itemslug).filter(date__lt=date).filter(type='cashin').aggregate(sum=Sum('amount'))['sum']
try:
result = round(latestvalue/paidup * 100,2)
except ZeroDivisionError :
result = 0
results.append(result)
return render(request, 'overview/detail.html',
{
'result':results,
})
unfortunately I get the TypeError : 'Value object is not subscriptable'
+ might be the case there are some other errors in my code.. Many thanks to have a look !!
Thanks,
How about simplifying it a bit:
latestvalue = Value.objects.get(item__slug=itemslug, date=date).amount
paidup = (CashFlow.objects
.filter(item__slug=itemslug, date__lt=date, type='cashin')
.aggregate(sum=Sum('amount'))['sum'])
I did the code for insert records from so_parts table to so_bo table using Query...How can I use ORM method to do this kind of job. Is there any other way(best)to do that? Here is my code`
`
#api.multi
def save_rapair_parts(self, vals):
#get todays date and convert it to string
created_date = datetime.datetime.today().strftime("%m/%d/%Y")
str_date = str(created_date)
so_p_id = self.so_p_id.id
bo_status = self.bo_status
so_part_t = self.so_part_t
so_part_sno = self.so_part_sno
product = self.so_part_product
product_str = 'Repair '+str(product)
part_id = self.id
bench_order_table.search(['id','bo_sno','created_date','bo_number','rep_description','bo_status'])
#insert details intoso bench orders
`
if so_part_t=='r_b':
try:
sequence = self.env['ir.sequence'].next_by_code('so.benchorder') or '/'
str_sequence = str(sequence)
query = """SELECT so_work_authorization FROM my_depots_so WHERE id=%d """ % (so_p_id)
self.env.cr.execute(query)
result = self.env.cr.fetchall()
result_number = json.dumps(result, ensure_ascii=False)
strip_number = result_number.strip('\' \" [] ')
work_auth_no = str(strip_number)
work_auth_no += "-"
work_auth_no += str_sequence
insert ="""INSERT INTO my_depots_so_bo(id,so_bo_id,bo_sno,created_date,bo_number,rep_description,bo_status) values %s """
parameters = (part_id,so_p_id,so_part_sno,str_date,work_auth_no,product_str,bo_status)
self.env.cr.execute(insert,(parameters,))
my_depots_bo(id,bo_sno,created_date,bo_number,rep_description,bo_status) values %s """
# self.env.cr.execute(insert_query, (parameters,))
except Exception:
print "Error in inserting values"`
yes there is a better way because when you use ORM
method you also checks access right for user to:
for your select query:
rec = self.env['my.depots.so'].search_read(['id', '=', so_p_id], ['so_work_authorization'])
if rec:
rec = rec[0] # search_read return a list of dictionary
so_work_authorization = rec['so_work_authorization']
# and do what ever you want with the result
# to create
# call create method witch accept a dictionary
# field_name : value
new_rec = self.env['my.depots.so.bo'].create({
'so_bo_id': so_p_id, # many2one must be an integer value
'bo_sno': bo_nso_value,
'bo_number': value_of_number,
# ....
# ....
# add al field
}) # create return the new created record as model object
for inserting use: self.env['model.name'].create(vals)
for updating use : self.env['model.name'].write(vals)
using ORM method makes sure that user don't pass the security access rigths
Hope you get the idea
I'm trying to get the next and previous objects of a comic book issue. Simply changing the id number or filtering through date added is not going to work because I don't add the issues sequentially.
This is how my views are setup and it WORKS for prev_issue and does return the previous object, but it returns the last object for next_issue and I do not know why.
def issue(request, issue_id):
issue = get_object_or_404(Issue, pk=issue_id)
title = Title.objects.filter(issue=issue)
prev_issue = Issue.objects.filter(title=title).filter(number__lt=issue.number)[0:1]
next_issue = Issue.objects.filter(title=title).filter(number__gt=issue.number)[0:1]
Add an order_by clause to ensure it orders by number.
next_issue = Issue.objects.filter(title=title, number__gt=issue.number).order_by('number').first()
I know this is a bit late, but for anyone else, django does have a nicer way to do this, see https://docs.djangoproject.com/en/1.7/ref/models/instances/#django.db.models.Model.get_previous_by_FOO
So the answer here would be something something like
next_issue = Issue.get_next_by_number(issue, title=title)
Django managers to do that with a bit of meta class cleaverness.
If it's required to find next and previous objects ordered by field values that can be equal and those fields are not of Date* type, the query gets slightly complex, because:
ordering on objects with same values limiting by [:1] will always produce same result for several objects;
object can itself be included in resulting set.
Here's are querysets that also take into account the primary keys to produce a correct result (assuming that number parameter from OP is not unique and omitting the title parameter as it's irrelevant for the example):
Previous:
prev_issue = (Issue.objects
.filter(number__lte=issue.number, id__lt=instance.id)
.exclude(id=issue.id)
.order_by('-number', '-id')
.first())
Next:
next_issue = (Issue.objects
.filter(number__gte=issue.number, id__gt=instance.id)
.exclude(id=issue.id)
.order_by('number', 'id')
.first())
from functools import partial, reduce
from django.db import models
def next_or_prev_instance(instance, qs=None, prev=False, loop=False):
if not qs:
qs = instance.__class__.objects.all()
if prev:
qs = qs.reverse()
lookup = 'lt'
else:
lookup = 'gt'
q_list = []
prev_fields = []
if qs.query.extra_order_by:
ordering = qs.query.extra_order_by
elif qs.query.order_by:
ordering = qs.query.order_by
elif qs.query.get_meta().ordering:
ordering = qs.query.get_meta().ordering
else:
ordering = []
ordering = list(ordering)
if 'pk' not in ordering and '-pk' not in ordering:
ordering.append('pk')
qs = qs.order_by(*ordering)
for field in ordering:
if field[0] == '-':
this_lookup = (lookup == 'gt' and 'lt' or 'gt')
field = field[1:]
else:
this_lookup = lookup
q_kwargs = dict([(f, get_model_attr(instance, f))
for f in prev_fields])
key = "%s__%s" % (field, this_lookup)
q_kwargs[key] = get_model_attr(instance, field)
q_list.append(models.Q(**q_kwargs))
prev_fields.append(field)
try:
return qs.filter(reduce(models.Q.__or__, q_list))[0]
except IndexError:
length = qs.count()
if loop and length > 1:
return qs[0]
return None
next_instance = partial(next_or_prev_instance, prev=False)
prev_instance = partial(next_or_prev_instance, prev=True)
note that do not use object.get(pk=object.pk + 1) these sorts of things, IntegrityError occurs if object at that pk is deleted, hence always use a query set
for visitors:
''' Useage '''
"""
# Declare our item
store = Store.objects.get(pk=pk)
# Define our models
stores = Store.objects.all()
# Ask for the next item
new_store = get_next_or_prev(stores, store, 'next')
# If there is a next item
if new_store:
# Replace our item with the next one
store = new_store
"""
''' Function '''
def get_next_or_prev(models, item, direction):
'''
Returns the next or previous item of
a query-set for 'item'.
'models' is a query-set containing all
items of which 'item' is a part of.
direction is 'next' or 'prev'
'''
getit = False
if direction == 'prev':
models = models.reverse()
for m in models:
if getit:
return m
if item == m:
getit = True
if getit:
# This would happen when the last
# item made getit True
return models[0]
return False
original author
Usage
# you MUST call order by to pass in an order, otherwise QuerySet.reverse will not work
qs = Model.objects.all().order_by('pk')
q = qs[0]
prev = get_next_or_prev(qs, q, 'prev')
next = get_next_or_prev(qs, q, 'next')
next_obj_id = int(current_obj_id) + 1
next_obj = Model.objects.filter(id=next_obj_id).first()
prev_obj_id= int(current_obj_id) - 1
prev_obj = Model.objects.filter(id=prev_obj_id).first()
#You have nothing to loose here... This works for me
I've got this complex filtering mechanism...
d = copy(request.GET)
d.setdefault('sort_by', 'created')
d.setdefault('sort_dir', 'desc')
form = FilterShipmentForm(d)
filter = {
'status': ShipmentStatuses.ACTIVE
}
exclude = {}
if not request.user.is_staff:
filter['user__is_staff'] = False
if request.user.is_authenticated():
exclude['user__blocked_by__blocked'] = request.user
if form.is_valid():
d = form.cleaned_data
if d.get('pickup_city'): filter['pickup_address__city__icontains'] = d['pickup_city']
if d.get('dropoff_city'): filter['dropoff_address__city__icontains'] = d['dropoff_city']
if d.get('pickup_province'): filter['pickup_address__province__exact'] = d['pickup_province']
if d.get('dropoff_province'): filter['dropoff_address__province__exact'] = d['dropoff_province']
if d.get('pickup_country'): filter['pickup_address__country__exact'] = d['pickup_country']
if d.get('dropoff_country'): filter['dropoff_address__country__exact'] = d['dropoff_country']
if d.get('min_price'): filter['target_price__gte'] = d['min_price']
if d.get('max_price'): filter['target_price__lte'] = d['max_price']
if d.get('min_distance'): filter['distance__gte'] = d['min_distance'] * 1000
if d.get('max_distance'): filter['distance__lte'] = d['max_distance'] * 1000
if d.get('available_on'): # <--- RELEVANT BIT HERE ---
filter['pickup_earliest__lte'] = d['available_on'] # basically I want "lte OR none"
filter['pickup_latest__gte'] = d['available_on']
if d.get('shipper'): filter['user__username__iexact'] = d['shipper']
order = ife(d['sort_dir'] == 'desc', '-') + d['sort_by']
shipments = Shipment.objects.filter(**filter).exclude(**exclude).order_by(order) \
.annotate(num_bids=Count('bids'), min_bid=Min('bids__amount'), max_bid=Max('bids__amount'))
And now my client tells me he wants pickup/drop-off dates to be 'flexible' as an option. So I've updated the DB to allow dates to be NULL for this purpose, but now the "available for pickup on" filter won't work as expected. It should include NULL/None dates. Is there an easy fix for this?
Flip the logic and use exclude(). What you really want to do is exclude any data that specifies a date that doesn't fit. If pickup_latest and pickup_earliest are NULL it shouldn't match the exclude query and wont be removed. Eg
exclude['pickup_latest__lt'] = d['available_on']
exclude['pickup_earliest__gt'] = d['available_on']
Most database engines don't like relational comparisons with NULL values. Use <field>__isnull to explicitly check if a value is NULL in the database, but you'll need to use Q objects to OR the conditions together.
Don't think that's actually a django-specific question. Variable 'd' is a python dictionary, no? If so, you can use this:
filter['pickup_latest__gte'] = d.get('available_on', None)