Changes between Version 3 and Version 4 of new_meta_api

Timestamp:

Jul 11, 2014, 5:20:39 AM (10 years ago)

Author:

pirosb3

Comment:

--

new_meta_api

@@ -41 +41 @@
 
 ===== Related Object
-A Related Object is a relation from another model (such as a ForeignKey) that points to the current model
+A Related Object is a one-to-many relation from another model (such as a ForeignKey) that points to the current model
 {{{
 class City(models.Model):
@@ -50 +50 @@
     city = models.ForeignKey(City)
 }}}
-     
+In this case, City has a related object from Person (as you can access person_set)
 
-== Endpoints
+===== Related M2M
+A Related M2M is a M2M relation from another model that points to the current model
+{{{
+class City(models.Model):
+    name = models.CharField(max_length=100)
 
+class Person(models.Model):
+    # M2M fields
+    cities_lived_in = models.ManyToManyField(City)
+}}}
+ 
+In this case, City has a related m2m from Person
+
+===== Virtual
+Virtual fields do not necessarily have an entry on the database, they are "Django fields" such as a GenericRelation
+{{{
+class Person(models.Model):
+    content_type = models.ForeignKey(ContentType, related_name='+')
+    object_id_ = models.PositiveIntegerField()
+    item = GenericForeignKey('content_type', 'object_id')
+}}}
+GenericForeignKey uses content_type and object_id to keep track of what model type and id is set by item, but item itself does not have a concrete presence on the database.
+In this case, item is a virtual field.