diff --git a/src/infi/clickhouse_orm/query.py b/src/infi/clickhouse_orm/query.py index 16de5ba..9298deb 100644 --- a/src/infi/clickhouse_orm/query.py +++ b/src/infi/clickhouse_orm/query.py @@ -293,6 +293,8 @@ class QuerySet(object): self._grouping_with_totals = False self._fields = model_cls.fields().keys() self._limits = None + self._limit_by = None + self._limit_by_fields = None self._distinct = False self._final = False @@ -332,6 +334,24 @@ class QuerySet(object): qs._limits = (start, stop - start) return qs + def limit_by(self, offset_limit, *fields): + if isinstance(offset_limit, six.integer_types): + # Single limit + assert offset_limit >= 0, 'negative limits are not supported' + qs = copy(self) + qs._limit_by = (0, offset_limit) + qs._limit_by_fields = fields + return qs + else: + # Offset, limit + offset = offset_limit[0] + limit = offset_limit[1] + assert offset >= 0 and limit >= 0, 'negative limits are not supported' + qs = copy(self) + qs._limit_by = (offset, limit) + qs._limit_by_fields = fields + return qs + def select_fields_as_sql(self): """ Returns the selected fields or expressions as a SQL string. @@ -369,6 +389,10 @@ class QuerySet(object): if self._limits: sql += '\nLIMIT %d, %d' % self._limits + if self._limit_by: + sql += '\nLIMIT %d, %d' % self._limit_by + sql += ' BY %s' % comma_join('`%s`' % field for field in self._limit_by_fields) + return sql def order_by_as_sql(self): diff --git a/tests/test_querysets.py b/tests/test_querysets.py index b17933b..e1a7f08 100644 --- a/tests/test_querysets.py +++ b/tests/test_querysets.py @@ -432,6 +432,12 @@ class AggregateTestCase(TestCaseWithData): qs = Mdl.objects_in(self.database).filter(the__next__number__gt=1) self.assertEqual(qs.conditions_as_sql(), 'the__next__number > 1') + def test_limit_by(self): + qs = Person.objects_in(self.database).aggregate('first_name', 'last_name', 'height', n='count()').\ + order_by('first_name', '-height').limit_by(1, 'first_name') + self.assertEqual(qs.count(), 94) + self.assertEqual(list(qs)[89].last_name, 'Bowen') + Color = Enum('Color', u'red blue green yellow brown white black')