From 9a72913edd10dbf2214397b20c3f5f501afd506b Mon Sep 17 00:00:00 2001 From: Ian Kelly Date: Fri, 10 Oct 2008 17:15:58 +0000 Subject: [PATCH] Fixed .distinct() not working with slicing in Oracle, due to the row numbers necessarily being distinct. git-svn-id: http://code.djangoproject.com/svn/django/trunk@9221 bcc190cf-cafb-0310-a4f2-bffc1f526a37 --- django/db/backends/oracle/query.py | 46 ++++++------------------- tests/regressiontests/queries/models.py | 6 ++++ 2 files changed, 17 insertions(+), 35 deletions(-) diff --git a/django/db/backends/oracle/query.py b/django/db/backends/oracle/query.py index 85e2f68822..4bdce9225c 100644 --- a/django/db/backends/oracle/query.py +++ b/django/db/backends/oracle/query.py @@ -26,8 +26,16 @@ def query_class(QueryClass, Database): class OracleQuery(QueryClass): def resolve_columns(self, row, fields=()): - index_start = len(self.extra_select.keys()) - values = [self.convert_values(v, None) for v in row[:index_start]] + # If this query has limit/offset information, then we expect the + # first column to be an extra "_RN" column that we need to throw + # away. + if self.high_mark is not None or self.low_mark: + rn_offset = 1 + else: + rn_offset = 0 + index_start = rn_offset + len(self.extra_select.keys()) + values = [self.convert_values(v, None) + for v in row[rn_offset:index_start]] for value, field in map(None, row[index_start:], fields): values.append(self.convert_values(value, field)) return values @@ -97,49 +105,17 @@ def query_class(QueryClass, Database): sql, params = super(OracleQuery, self).as_sql(with_limits=False, with_col_aliases=with_col_aliases) else: - # `get_columns` needs to be called before `get_ordering` to - # populate `_select_alias`. - self.pre_sql_setup() - self.get_columns() - ordering = self.get_ordering() - - # Oracle's ROW_NUMBER() function requires an ORDER BY clause. - if ordering: - rn_orderby = ', '.join(ordering) - else: - # Create a default ORDER BY since none was specified. - qn = self.quote_name_unless_alias - opts = self.model._meta - rn_orderby = '%s.%s' % (qn(opts.db_table), - qn(opts.fields[0].db_column or opts.fields[0].column)) - - # Ensure the base query SELECTs our special "_RN" column - self.extra_select['_RN'] = ('ROW_NUMBER() OVER (ORDER BY %s)' - % rn_orderby, '') sql, params = super(OracleQuery, self).as_sql(with_limits=False, with_col_aliases=True) # Wrap the base query in an outer SELECT * with boundaries on # the "_RN" column. This is the canonical way to emulate LIMIT # and OFFSET on Oracle. - sql = 'SELECT * FROM (%s) WHERE "_RN" > %d' % (sql, self.low_mark) + sql = 'SELECT * FROM (SELECT ROW_NUMBER() OVER (ORDER BY 1) AS "_RN", "_SUB".* FROM (%s) "_SUB") WHERE "_RN" > %d' % (sql, self.low_mark) if self.high_mark is not None: sql = '%s AND "_RN" <= %d' % (sql, self.high_mark) return sql, params - def set_limits(self, low=None, high=None): - super(OracleQuery, self).set_limits(low, high) - # We need to select the row number for the LIMIT/OFFSET sql. - # A placeholder is added to extra_select now, because as_sql is - # too late to be modifying extra_select. However, the actual sql - # depends on the ordering, so that is generated in as_sql. - self.extra_select['_RN'] = ('1', '') - - def clear_limits(self): - super(OracleQuery, self).clear_limits() - if '_RN' in self.extra_select: - del self.extra_select['_RN'] - _classes[QueryClass] = OracleQuery return OracleQuery diff --git a/tests/regressiontests/queries/models.py b/tests/regressiontests/queries/models.py index fc21cef3cc..f3831df5b6 100644 --- a/tests/regressiontests/queries/models.py +++ b/tests/regressiontests/queries/models.py @@ -334,6 +334,12 @@ Bug #4464 >>> Item.objects.filter(tags__in=[t1, t2]).filter(tags=t3) [] +Make sure .distinct() works with slicing (this was broken in Oracle). +>>> Item.objects.filter(tags__in=[t1, t2]).order_by('name')[:3] +[, , ] +>>> Item.objects.filter(tags__in=[t1, t2]).distinct().order_by('name')[:3] +[, ] + Bug #2080, #3592 >>> Author.objects.filter(item__name='one') | Author.objects.filter(name='a3') [, ]