Fixed #20888 -- Added support for column order in class-based indexes.

This commit is contained in:
Akshesh 2016-07-22 18:22:44 +05:30 committed by Tim Graham
parent 6b842c5998
commit 311a8e8d50
4 changed files with 60 additions and 6 deletions

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@ -17,6 +17,11 @@ class Index(object):
if not fields:
raise ValueError('At least one field is required to define an index.')
self.fields = fields
# A list of 2-tuple with the field name and ordering ('' or 'DESC').
self.fields_orders = [
(field_name[1:], 'DESC') if field_name.startswith('-') else (field_name, '')
for field_name in self.fields
]
self.name = name or ''
if self.name:
errors = self.check_name()
@ -38,15 +43,17 @@ class Index(object):
return errors
def create_sql(self, model, schema_editor):
fields = [model._meta.get_field(field) for field in self.fields]
fields = [model._meta.get_field(field_name) for field_name, order in self.fields_orders]
tablespace_sql = schema_editor._get_index_tablespace_sql(model, fields)
columns = [field.column for field in fields]
quote_name = schema_editor.quote_name
columns = [
('%s %s' % (quote_name(field.column), order)).strip()
for field, (field_name, order) in zip(fields, self.fields_orders)
]
return schema_editor.sql_create_index % {
'table': quote_name(model._meta.db_table),
'name': quote_name(self.name),
'columns': ', '.join(quote_name(column) for column in columns),
'columns': ', '.join(columns),
'extra': tablespace_sql,
}
@ -82,8 +89,12 @@ class Index(object):
fit its size by truncating the excess length.
"""
table_name = model._meta.db_table
column_names = [model._meta.get_field(field).column for field in self.fields]
hash_data = [table_name] + column_names + [self.suffix]
column_names = [model._meta.get_field(field_name).column for field_name, order in self.fields_orders]
column_names_with_order = [
(('-%s' if order else '%s') % column_name)
for column_name, (field_name, order) in zip(column_names, self.fields_orders)
]
hash_data = [table_name] + column_names_with_order + [self.suffix]
self.name = '%s_%s_%s' % (
table_name[:11],
column_names[0][:7],

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@ -34,6 +34,20 @@ options`_.
A list of the name of the fields on which the index is desired.
By default, indexes are created with an ascending order for each column. To
define an index with a descending order for a column, add a hyphen before the
field's name.
For example ``Index(fields=['headline', '-pub_date'])`` would create SQL with
``(headline, pub_date DESC)``. Index ordering isn't supported on MySQL. In that
case, a descending index is created as a normal index.
.. admonition:: Support for column ordering on SQLite
Column ordering is supported on SQLite 3.3.0+ and only for some database
file formats. Refer to the `SQLite docs
<https://www.sqlite.org/lang_createindex.html>`_ for specifics.
``name``
--------

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@ -46,6 +46,11 @@ class IndexesTests(TestCase):
index.set_name_with_model(Book)
self.assertEqual(index.name, 'model_index_author_0f5565_idx')
# '-' for DESC columns should be accounted for in the index name.
index = models.Index(fields=['-author'])
index.set_name_with_model(Book)
self.assertEqual(index.name, 'model_index_author_708765_idx')
# fields may be truncated in the name. db_column is used for naming.
long_field_index = models.Index(fields=['pages'])
long_field_index.set_name_with_model(Book)

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@ -156,6 +156,12 @@ class SchemaTests(TransactionTestCase):
counts['indexes'] += 1
return counts
def assertIndexOrder(self, table, index, order):
constraints = self.get_constraints(table)
self.assertIn(index, constraints)
index_orders = constraints[index]['orders']
self.assertTrue(all([(val == expected) for val, expected in zip(index_orders, order)]))
# Tests
def test_creation_deletion(self):
"""
@ -1597,6 +1603,24 @@ class SchemaTests(TransactionTestCase):
editor.remove_index(Author, index)
self.assertNotIn('name', self.get_indexes(Author._meta.db_table))
def test_order_index(self):
"""
Indexes defined with ordering (ASC/DESC) defined on column
"""
with connection.schema_editor() as editor:
editor.create_model(Author)
# The table doesn't have an index
self.assertNotIn('title', self.get_indexes(Author._meta.db_table))
index_name = 'author_name_idx'
# Add the index
index = Index(fields=['name', '-weight'], name=index_name)
with connection.schema_editor() as editor:
editor.add_index(Author, index)
if connection.features.supports_index_column_ordering:
if connection.features.uppercases_column_names:
index_name = index_name.upper()
self.assertIndexOrder(Author._meta.db_table, index_name, ['ASC', 'DESC'])
def test_indexes(self):
"""
Tests creation/altering of indexes