Hi Serge, sorry for the expert warning you gave me on performance. But I have trouble following your really techincal suggestion, my goal is to have one table with measures that is related to three models with different geometries, so I can't use a foreign key in measure table, I don't understand the use of related obj, can you point me to a good source ?
thanks On Friday, February 5, 2016 at 7:40:53 PM UTC+1, Sergiy Khohlov wrote: > > I’ve decided to use connection via key. and using via key directly or > via related objects. Such us Car -> Point (multiline). Reason is simple > : django creates not perfect database structure and I would like think > about performance as soon as possible. My project contains Car and points > related to the car and of course route (POLYLINE). I deceided to use > trivial PostGIS model for avoiding bottleneck that use simple code in > view. It is really easy to change view and hard to change models in case > of important data present. (Every 100km generates 2000 points which cause > and route length and motor service interval). In case of success Abstract > class (with good performance) let me know please. > > Many thanks, > > Serge > > > +380 636150445 > skype: skhohlov > > On Fri, Feb 5, 2016 at 7:25 PM, Luca Moiana <luca....@gmail.com > <javascript:>> wrote: > >> Hi Serge, >> >> thank you for your reply. >> >> I'm working on an environmental monitoring app, where I want to store, >> and serve, monitoring value on different geometries, points, tracks or >> polygon. >> That's why I'm trying to use a polymorphic model in order to have one >> entity and multiple geometries. >> >> Cheers >> >> L >> >> >> On Friday, February 5, 2016 at 10:51:31 AM UTC+1, Sergiy Khohlov wrote: >>> >>> I would like as simple question : Are you planning to have some >>> advantages using this abstract class ? >>> I’m working on similar product (look like you are making energy >>> pipeline system based on postgis and gjango). My product is GTS system >>> which includes POINTS (datas are received via GTS devices mounted on >>> vehicles). Polylines (car route for selected time range), etc. Producing >>> abstract class can decrease DB productivity. Which one functional do you >>> need in case of abstract class for different types usage ? >>> >>> Many thanks, >>> >>> Serge >>> >>> >>> +380 636150445 >>> skype: skhohlov >>> >>> On Fri, Feb 5, 2016 at 11:07 AM, Luca Moiana <luca....@gmail.com> wrote: >>> >>>> Hi Collin, >>>> >>>> Sorry for the late reply, but I still don't get the google groups; >>>> >>>> Yes, I am tryng to crete a models where you can choose between the >>>> three geometry types. >>>> >>>> I'll go back to my app and test the code you suggested and post again >>>> the error. >>>> >>>> thanks >>>> >>>> >>>> On Wednesday, October 28, 2015 at 7:00:26 PM UTC+1, Collin Anderson >>>> wrote: >>>>> >>>>> Hello, >>>>> >>>>> Are you trying to combine multiple models into one, like this? >>>>> >>>>> class PolyModel(pdmpunto, pdmtransetto, pdmarea): >>>>> pass >>>>> >>>>> You could also try asking on the geodjango list: >>>>> http://groups.google.com/group/geodjango >>>>> >>>>> Collin >>>>> >>>>> On Monday, October 26, 2015 at 7:18:24 AM UTC-4, Luca Moiana wrote: >>>>>> >>>>>> Hi, working on my first django app, and run into a problem. >>>>>> >>>>>> I tend to create geodjango objects, and add all data from external >>>>>> tables with pk. >>>>>> >>>>>> Then I want to have different geometries 8points, lines, polygons) >>>>>> into a unique polymorphic class, can I do that? >>>>>> >>>>>> I have an error that I'll document later, and I'm trying to figure >>>>>> out what to do. >>>>>> >>>>>> Here is the model: >>>>>> import datetime >>>>>> >>>>>> from django.db import models >>>>>> from django.contrib.gis.db import models as geomodels >>>>>> from django.utils import timezone >>>>>> from django.forms import ModelForm >>>>>> from polymorphic import PolymorphicModel >>>>>> >>>>>> # Geometria linea da monitorare >>>>>> class geolinea(geomodels.Model): >>>>>> progetto = models.CharField(max_length=14, primary_key=True) >>>>>> geom = geomodels.MultiLineStringField() >>>>>> objects = geomodels.GeoManager() >>>>>> def __str__(self): >>>>>> return '%s' % (self.progetto) >>>>>> # Oggetto Progetto soggetto a PMA >>>>>> class linea(models.Model): >>>>>> progetto = models.ForeignKey(geolinea) >>>>>> nome = models.CharField(max_length=200) >>>>>> TENSIONE = ( >>>>>> ('132', '132kV'), >>>>>> ('150', '150kV'), >>>>>> ('220', '220kV'), >>>>>> ('380', '380kV'), >>>>>> ) >>>>>> tensione = models.CharField(max_length=5, >>>>>> choices=TENSIONE) >>>>>> def __str__(self): >>>>>> return '%s' % (self.nome) >>>>>> >>>>>> # Geometria dei pdm >>>>>> class pdmpunto(geomodels.Model): >>>>>> linea = models.ForeignKey(linea) >>>>>> numero = models.CharField(max_length=3) >>>>>> geom = geomodels.PointField() >>>>>> objects = geomodels.GeoManager() >>>>>> >>>>>> class pdmtransetto(geomodels.Model): >>>>>> linea = models.ForeignKey(linea) >>>>>> numero = models.CharField(max_length=3) >>>>>> geom = geomodels.LineStringField() >>>>>> objects = geomodels.GeoManager() >>>>>> >>>>>> class pdmarea(geomodels.Model): >>>>>> linea = models.ForeignKey(linea) >>>>>> numero = models.CharField(max_length=3) >>>>>> geom = geomodels.PolygonField() >>>>>> objects = geomodels.GeoManager() >>>>>> >>>>>> class pdm(PolymorphicModel): >>>>>> numero = models.CharField(max_length=14, primary_key=True) >>>>>> class punto(pdm): >>>>>> rifpunto = models.ForeignKey(pdmpunto) >>>>>> class transetto(pdm): >>>>>> riftransetto = models.ForeignKey(pdmtransetto) >>>>>> class area(pdm): >>>>>> rifarea = models.ForeignKey(pdmarea) >>>>>> >>>>>> >>>>>> >>>>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Django users" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to django-users...@googlegroups.com. >>>> To post to this group, send email to django...@googlegroups.com. >>>> Visit this group at https://groups.google.com/group/django-users. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/django-users/cd243d25-0aff-446d-b9c9-cb5682d9bdf3%40googlegroups.com >>>> >>>> <https://groups.google.com/d/msgid/django-users/cd243d25-0aff-446d-b9c9-cb5682d9bdf3%40googlegroups.com?utm_medium=email&utm_source=footer> >>>> . >>>> >>>> For more options, visit https://groups.google.com/d/optout. >>>> >>> >>> -- >> You received this message because you are subscribed to the Google Groups >> "Django users" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to django-users...@googlegroups.com <javascript:>. >> To post to this group, send email to django...@googlegroups.com >> <javascript:>. >> Visit this group at https://groups.google.com/group/django-users. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/django-users/70b475b9-34d7-498c-ad1f-d27f020d02d0%40googlegroups.com >> >> <https://groups.google.com/d/msgid/django-users/70b475b9-34d7-498c-ad1f-d27f020d02d0%40googlegroups.com?utm_medium=email&utm_source=footer> >> . >> >> For more options, visit https://groups.google.com/d/optout. >> > > -- You received this message because you are subscribed to the Google Groups "Django users" group. 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