Ok, data transfer error fixed and data now in table. However, I am still not getting a value for {{i.seats_remaining}}. It comes out blank.
I had an error in the view that I corrected as below but still does not give results.
def winery_events_view(request):
winery_events = WineryEvents.objects.filter(publish='Y').filter(event_date__gte=datetime.now()).order_by('event_date')
WineryEvents.objects.annotate(
seats_remaining = F('seating')-Sum('reservations__seats_reserved')
)
return render(request, 'restaurant/winery_events.html',{"winery_events":winery_events, })
---------------------
On Monday, September 10, 2018 at 2:21:59 PM UTC-5, mab.mo...@gmail.com wrote:
Hello Simon,I tried implementing your recommendations today and all appeared to go well except that I was not getting any results from the query for remaining seating on the html template. I took a look at my reservation table and the data was gone. I had the data in an original table I copied from and tried to do the same but now have the following error....INSERT INTO restaurant_reservation (id, seats_reserved, event_id, user_id) SELECT winery_event_reservation_id, winery_event_adult_seats_reserved, event_id, user_id FROM winery_event_reservations; ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`campodibella`.`restaurant_reservation`, CONSTRAINT `restaurant_reservati_event_ id_d13deeb7_fk_restauran` FOREIGN KEY (`event_id`) REFERENCES `restaurant_wineryevents` (`id`)) I went through all the migrate/makemigrations/migrate operations too.Here is my FROM table structure...mysql> describe winery_event_reservations;+------------------------------------+------------------+--- ---+-----+-------------------+ -----------------------------+ | Field | Type | Null | Key | Default | Extra |+------------------------------------+------------------+--- ---+-----+-------------------+ -----------------------------+ | winery_event_reservation_id | int(10) unsigned | NO | PRI | NULL | auto_increment || event_id | int(10) | YES | | NULL | || user_id | int(10) | YES | | NULL | || winery_event_adult_seats_reserved | int(10) | YES | | NULL | | | winery_event_child_seats_reserved | int(10) | YES | | NULL | | | winery_event_reservation_timestamp | timestamp | NO | | CURRENT_TIMESTAMP | on update CURRENT_TIMESTAMP | +------------------------------------+------------------+--- ---+-----+-------------------+ -----------------------------+ Copied TO table...mysql> describe restaurant_reservation;+----------------+------------------+------+-----+---------+ ----------------+ | Field | Type | Null | Key | Default | Extra |+----------------+------------------+------+-----+---------+ ----------------+ | id | int(11) | NO | PRI | NULL | auto_increment || user_id | int(11) | NO | | NULL | || seats_reserved | int(10) unsigned | NO | | NULL | || event_id | int(11) | NO | MUL | NULL | |+----------------+------------------+------+-----+---------+ ----------------+ 4 rows in set (0.00 sec)I did rename some fields and tables here is my current setup..MODELSclass WineryEvents(models.Model):event_date = models.DateField(auto_now_add=False) event_time = models.TimeField(auto_now_add=False) event_type = models.CharField(max_length=20, choices=EVENT_TYPE) seating = models.PositiveIntegerField(default=0) title = models.CharField(max_length=200) description = models.TextField()menu = models.TextField()price = models.DecimalField(max_digits=6, decimal_places=2) publish = models.CharField(max_length=1, choices=PUBLISH_CHOICE)def __int__(self):return self.titleclass Reservation(models.Model):user_id = models.IntegerField(default=0)event = models.ForeignKey(WineryEvents, related_name='reservations', on_delete=models.PROTECT) seats_reserved = models.PositiveIntegerField(default=0) def __int__(self):return self.eventVIEWdef winery_events_view(request):winery_events = WineryEvents.objects.filter(publish='Y').filter(event_ date__gte=datetime.now()). order_by('event_date') WineryEvents.objects.annotate( seats_remaining = F('seating')-Sum('reservations__seats') )return render(request, 'restaurant/winery_events.html',{"winery_events":winery_ events, }) TEMPLATE....{% for i in winery_events %}<div class='first-column'><h3 style='display:inline;'>{{ i.event_date|date:"l M j, Y" }} {{ i.event_time|date:"g:i A" }}</h3><br><p style='display:inline;'>{{i.event_type|title}} - {{i.title|title}}</p><br> <a style='display:inline;' href="{% url 'make_reservation' pk=i.pk %}">Purchase Reservation ${{i.price}}</a> <p style='display: inline;'>Seats Remaining {{i.seats_remaining}}</p><p> {{ i.description|safe}} </p></div>....Any further help would be greatly appreciated. Thanks in advance.Marc
On Friday, September 7, 2018 at 10:08:07 AM UTC-5, Simon Charette wrote:The annotate(seats_remaining=...) will add a `seats_remaining` attribute to Eventinstances returned from the queryset so you should be able to use {{i.seats_remaining }}Cheers,
Le vendredi 7 septembre 2018 04:38:05 UTC-4, mab.mo...@gmail.com a écrit :Thank you Simon.I will take a look at annotations.How would I represent seats remaining in the template for loop? Here is what I have so far.....#####################{% for i in events %}<div class='first-column'><h3 style='display:inline;'>{{ i.event_date|date:"l M j, Y" }} {{ i.event_time|date:"g:i A" }}</h3><br><p style='display:inline;'>{{i.event_type|title}} - {{i.title|title}}</p><br> <a style='display:inline;' href="{% url 'make_reservation' pk=i.pk %}">Purchase Reservation ${{i.price}}</a> <p style='display: inline;'>Seats Remaining ### VARIABLE HERE ###</p><p> {{ i.description|safe}} </p></div><div class='second-column' style="background-image: url('../static/restaurant/images/event_images/{{i.id}}. jpg'); background-size: cover;"> </div><div class='first-column' style="height:10px; border: 0px solid black;"></div><div class='second-column' style="height:10px; border: 0px solid black;"></div>{% endfor %}#####################
On Thursday, September 6, 2018 at 8:04:36 AM UTC-5, Simon Charette wrote:Hello there,You should be able to achieve what you're after by using annotations[0].In your case you'll want to declare your Event and Reservation relationship explicitly by usinga ForeignKeyclass Event(models.Model):...seating = models.PositiveIntegerField(default=0) class Reservation(models.Model):...event = models.ForeignKey(Event, related_name='reservations')seats = models.PositiveIntegerField(default=0) And perform the following queryEvent.objects.annotate(seats_remaining=F('seating') - Sum('reservations__seats').)Cheers,Simon
Le jeudi 6 septembre 2018 07:42:36 UTC-4, mab.mo...@gmail.com a écrit :QUESTIONI have an application that will make on-line reservations for a series of weekly events. I would like to display the list of upcoming events in an html template with the number of remaining seats available in a single html page. I was able to create views to display the list of upcoming events and another view to display the number of remaining seats available but I am unable to figure out how to nest the two into a single view. Example below...HTML OUTPUTEvent Title Week 1 - x amount of seats remaining for this eventEvent Title Week 2 - x amount of seats remainign for this eventEvent Title Week 3 - x amount of seats remaining for this eventand so on ....MODELSclass Events(models.Model):event_date = models.DateField(auto_now_add=False) event_time = models.TimeField(auto_now_add=False) event_type = models.CharField(max_length=20, choices=EVENT_TYPE) seating = models.IntegerField(default=0)title = models.CharField(max_length=200) description = models.TextField()menu = models.TextField()price = models.DecimalField(max_digits=6, decimal_places=2) publish = models.CharField(max_length=1, choices=PUBLISH_CHOICE)def __int__(self):return self.titleclass Reservations(models.Model):user_id = models.IntegerField(default=0)event_id = models.IntegerField(default=0)reservations = models.IntegerField(default=0)def __int__(self):return self.eventVIEWSdef events_view(request):events=Events.objects.filter(publish='Y').filter(event_ date__gte=datetime.now()). order_by('event_date') reservation_count = Reservations.objects. aggregate(Sum('reservations')) return render(request, 'restaurant/events.html',{"events":events, "reservation_count": reservation_count, }) def make_reservation_view(request, pk):event = Events.objects.get(id=pk)seating_available = Events.objects.get(id=pk)seating_available = seating_available.seatingreservation_count = Reservations.objects.filter(event_id=pk).aggregate(res_ sum=Sum('reservations')) res = reservation_count['res_sum']seats_remaining = seating_available - resreturn render(request, 'restaurant/make_reservation.html', {"event":event, \ "seats_remaining":seats_remaining,})
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