mirror of
https://github.com/django/django.git
synced 2024-12-23 01:25:58 +00:00
28 lines
1.2 KiB
Python
28 lines
1.2 KiB
Python
from django.db.models import CharField, Value
|
|
from django.db.models.functions import Left, Lower
|
|
from django.test import TestCase
|
|
|
|
from .models import Author
|
|
|
|
|
|
class LeftTests(TestCase):
|
|
@classmethod
|
|
def setUpTestData(cls):
|
|
Author.objects.create(name='John Smith', alias='smithj')
|
|
Author.objects.create(name='Rhonda')
|
|
|
|
def test_basic(self):
|
|
authors = Author.objects.annotate(name_part=Left('name', 5))
|
|
self.assertQuerysetEqual(authors.order_by('name'), ['John ', 'Rhond'], lambda a: a.name_part)
|
|
# If alias is null, set it to the first 2 lower characters of the name.
|
|
Author.objects.filter(alias__isnull=True).update(alias=Lower(Left('name', 2)))
|
|
self.assertQuerysetEqual(authors.order_by('name'), ['smithj', 'rh'], lambda a: a.alias)
|
|
|
|
def test_invalid_length(self):
|
|
with self.assertRaisesMessage(ValueError, "'length' must be greater than 0"):
|
|
Author.objects.annotate(raises=Left('name', 0))
|
|
|
|
def test_expressions(self):
|
|
authors = Author.objects.annotate(name_part=Left('name', Value(3), output_field=CharField()))
|
|
self.assertQuerysetEqual(authors.order_by('name'), ['Joh', 'Rho'], lambda a: a.name_part)
|