2018-07-01 04:49:20 +08:00
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from django.db import connection
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2020-06-16 16:01:34 +08:00
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from django.db.models import Value
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2018-04-04 00:24:04 +08:00
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from django.db.models.functions import Length, LPad, RPad
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2018-03-20 00:35:16 +08:00
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from django.test import TestCase
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2018-08-16 07:45:11 +08:00
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from ..models import Author
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2018-03-20 00:35:16 +08:00
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class PadTests(TestCase):
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def test_pad(self):
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Author.objects.create(name="John", alias="j")
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2018-07-01 04:49:20 +08:00
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none_value = (
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"" if connection.features.interprets_empty_strings_as_nulls else None
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2022-02-04 03:24:19 +08:00
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)
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2018-03-20 00:35:16 +08:00
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tests = (
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(LPad("name", 7, Value("xy")), "xyxJohn"),
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(RPad("name", 7, Value("xy")), "Johnxyx"),
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(LPad("name", 6, Value("x")), "xxJohn"),
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(RPad("name", 6, Value("x")), "Johnxx"),
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# The default pad string is a space.
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(LPad("name", 6), " John"),
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(RPad("name", 6), "John "),
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# If string is longer than length it is truncated.
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(LPad("name", 2), "Jo"),
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(RPad("name", 2), "Jo"),
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(LPad("name", 0), ""),
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(RPad("name", 0), ""),
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2018-07-01 04:49:20 +08:00
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(LPad("name", None), none_value),
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(RPad("name", None), none_value),
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2021-12-10 17:13:09 +08:00
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(LPad(Value(None), 1), none_value),
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(RPad(Value(None), 1), none_value),
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2018-07-01 04:49:20 +08:00
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(LPad("goes_by", 1), none_value),
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(RPad("goes_by", 1), none_value),
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2018-03-20 00:35:16 +08:00
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)
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for function, padded_name in tests:
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with self.subTest(function=function):
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authors = Author.objects.annotate(padded_name=function)
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self.assertQuerysetEqual(
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authors, [padded_name], lambda a: a.padded_name, ordered=False
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)
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def test_pad_negative_length(self):
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for function in (LPad, RPad):
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with self.subTest(function=function):
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with self.assertRaisesMessage(
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ValueError, "'length' must be greater or equal to 0."
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):
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function("name", -1)
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2018-04-04 00:24:04 +08:00
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def test_combined_with_length(self):
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Author.objects.create(name="Rhonda", alias="john_smith")
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Author.objects.create(name="♥♣♠", alias="bytes")
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2020-06-16 16:01:34 +08:00
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authors = Author.objects.annotate(filled=LPad("name", Length("alias")))
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2018-04-04 00:24:04 +08:00
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self.assertQuerysetEqual(
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authors.order_by("alias"),
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[" ♥♣♠", " Rhonda"],
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lambda a: a.filled,
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)
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