You know that Django allows for the creation of QuerySets from the database by making use of methods like
But can we create a QuerySet out of a combination of other QuerySets?
Say we wanted to create a QuerySet from data collected from two different models. The use of the
exclude() methods would not help here.
Or we might be creating a QuerySet with complex inclusions and exclusions using the
exclude() methods, and it would be simpler to create multiple QuerySets and then combine them into a single set.
It is possible to combine QuerySets into another QuerySet, and they do not have to be from the same model.
The Python union operator can be used to combine QuerySets that belong to the same model.
Two or more QuerySets can be combined using the union operator with the following syntax:
model_combination = model_set1 | model_set2 | model_set3
You can also use the
chain() method from the Itertools module, which allows you to combine two or more QuerySets from different models through concatenation.
from itertools import chain model_combination = list(chain(model_set1, model_set2))
Alternatively, you can use
union() to combine two or more QuerySets from different models, passing
all=TRUE if you want to allow duplicates.
model_combination = model_set1.union(model_set2, all=TRUE)
For some tips on working with Django on Sentry, have a look at these articles: