Merge pull request datajoint#966 from jverswijver/left_join_len_bug

Fix __len__() for left join QueryExpressions

Author: dimitri-yatsenko

CHANGELOG.md

@@ -6,6 +6,7 @@
 * Bugfix - Replace use of numpy aliases of built-in types with built-in type. (#938) PR #939
 * Bugfix - `ExternalTable.delete` should not remove row on error (#953) PR #956
 * Bugfix - Fix error handling of remove_object function in `s3.py` (#952) PR #955
+* Bugfix - Fix count for left-joined `QueryExpressions` (#951) PR #966
 * Bugfix - Fix assertion error when performing a union into a join (#930) PR #967
 
 ### 0.13.2 -- May 7, 2021

datajoint/expression.py

@@ -442,8 +442,10 @@ def tail(self, limit=25, **fetch_kwargs):
     def __len__(self):
         """:return: number of elements in the result set e.g. ``len(q1)``."""
         return self.connection.query(
-            'SELECT count(DISTINCT {fields}) FROM {from_}{where}'.format(
-                fields=self.heading.as_sql(self.primary_key, include_aliases=False),
+            'SELECT {select_} FROM {from_}{where}'.format(
+                select_=('count(*)' if any(self._left)
+                         else 'count(DISTINCT {fields})'.format(fields=self.heading.as_sql(
+                            self.primary_key, include_aliases=False))),
                 from_=self.from_clause(),
                 where=self.where_clause())).fetchone()[0]
 

docs-parts/intro/Releases_lang1.rst

@@ -5,6 +5,7 @@
 * Bugfix - Replace use of numpy aliases of built-in types with built-in type. (#938) PR #939
 * Bugfix - `ExternalTable.delete` should not remove row on error (#953) PR #956
 * Bugfix - Fix error handling of remove_object function in `s3.py` (#952) PR #955
+* Bugfix - Fix count for left-joined ``QueryExpressions`` (#951) PR #966
 * Bugfix - Fix assertion error when performing a union into a join (#930) PR #967
 
 0.13.2 -- May 7, 2021

tests/test_aggr_regressions.py

@@ -6,7 +6,8 @@
 from nose.tools import assert_equal, raises
 import datajoint as dj
 from . import PREFIX, CONN_INFO
-
+import uuid
+from .schema_uuid import Topic, Item, top_level_namespace_id
 schema = dj.Schema(PREFIX + '_aggr_regress', connection=dj.conn(**CONN_INFO))
 
 # --------------- ISSUE 386 -------------------
@@ -104,6 +105,17 @@ def test_issue558_part2():
     assert_equal(len(X & d), len((X & d).proj(id2='3')))
 
 
+def test_left_join_len():
+    Topic().add('jeff')
+    Item.populate()
+    Topic().add('jeff2')
+    Topic().add('jeff3')
+    q = Topic.join(Item - dict(topic_id=uuid.uuid5(top_level_namespace_id, 'jeff')),
+                   left=True)
+    qf = q.fetch()
+    assert len(q) == len(qf)
+
+
 def test_union_join():
     # https://github.com/datajoint/datajoint-python/issues/930
     A.insert(zip([100, 200, 300, 400, 500, 600]))

tests/test_s3.py

@@ -70,7 +70,7 @@ def test_remove_object_exception():
 
         # Apply our new minio client which has a user that does not exist
         schema.external['share'].s3.client = Minio(
-            'minio:9000',
+            S3_CONN_INFO['endpoint'],
             access_key='jeffjeff',
             secret_key='jeffjeff',
             secure=False)