queryset-tutorial
1.django queryset tutorial 1
https://docs.djangoproject.com/en/3.1/topics/db/queries/\`models.py'django 3.0 부터 extensions 에서 orm 사용할 때 error 난다https://stackoverflow.com/
2.django queryset tutorial 2
When you are filtering an object based on a ManyToManyField or a reverse ForeignKey, there are two different sorts of filter you may be interested in.
3.django orm tutorial 3
Django provides F expressions to allow such comparisons. Instances of F() act as a reference to a model field within a query. These references can the
4.Copying model instances
Copying model instances Although there is no built-in method for copying model instances, it is possible to easily create new instance with all field
5.Django Caching & QuerySet
Keep this caching behavior in mind, because it may bite you if you don’t use your QuerySets correctly. For example, the following will create two Quer