54 lines
2.0 KiB
Python
54 lines
2.0 KiB
Python
|
from django.db.models import CharField, Value as V
|
||
|
|
from django.db.models.functions import Lower, StrIndex, Substr, Upper
|
||
|
|
from django.test import TestCase
|
||
|
|
|
||
|
|
from ..models import Author
|
||
|
|
|
||
|
|
|
||
|
|
class SubstrTests(TestCase):
|
||
|
|
|
||
|
|
def test_basic(self):
|
||
|
|
Author.objects.create(name='John Smith', alias='smithj')
|
||
|
|
Author.objects.create(name='Rhonda')
|
||
|
|
authors = Author.objects.annotate(name_part=Substr('name', 5, 3))
|
||
|
|
self.assertQuerysetEqual(
|
||
|
|
authors.order_by('name'), [' Sm', 'da'],
|
||
|
|
lambda a: a.name_part
|
||
|
|
)
|
||
|
|
authors = Author.objects.annotate(name_part=Substr('name', 2))
|
||
|
|
self.assertQuerysetEqual(
|
||
|
|
authors.order_by('name'), ['ohn Smith', 'honda'],
|
||
|
|
lambda a: a.name_part
|
||
|
|
)
|
||
|
|
# If alias is null, set to first 5 lower characters of the name.
|
||
|
|
Author.objects.filter(alias__isnull=True).update(
|
||
|
|
alias=Lower(Substr('name', 1, 5)),
|
||
|
|
)
|
||
|
|
self.assertQuerysetEqual(
|
||
|
|
authors.order_by('name'), ['smithj', 'rhond'],
|
||
|
|
lambda a: a.alias
|
||
|
|
)
|
||
|
|
|
||
|
|
def test_start(self):
|
||
|
|
Author.objects.create(name='John Smith', alias='smithj')
|
||
|
|
a = Author.objects.annotate(
|
||
|
|
name_part_1=Substr('name', 1),
|
||
|
|
name_part_2=Substr('name', 2),
|
||
|
|
).get(alias='smithj')
|
||
|
|
|
||
|
|
self.assertEqual(a.name_part_1[1:], a.name_part_2)
|
||
|
|
|
||
|
|
def test_pos_gt_zero(self):
|
||
|
|
with self.assertRaisesMessage(ValueError, "'pos' must be greater than 0"):
|
||
|
|
Author.objects.annotate(raises=Substr('name', 0))
|
||
|
|
|
||
|
|
def test_expressions(self):
|
||
|
|
Author.objects.create(name='John Smith', alias='smithj')
|
||
|
|
Author.objects.create(name='Rhonda')
|
||
|
|
substr = Substr(Upper('name'), StrIndex('name', V('h')), 5, output_field=CharField())
|
||
|
|
authors = Author.objects.annotate(name_part=substr)
|
||
|
|
self.assertQuerysetEqual(
|
||
|
|
authors.order_by('name'), ['HN SM', 'HONDA'],
|
||
|
|
lambda a: a.name_part
|
||
|
|
)
|