Merge pull request datajoint#965 from jverswijver/ephys_regression_sql_mode

Fix regression sql mode

Author: guzman-raphael

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 sql code generation to comply with sql mode `ONLY_FULL_GROUP_BY` (#916) PR #965
 * Bugfix - Fix count for left-joined `QueryExpressions` (#951) PR #966
 * Bugfix - Fix assertion error when performing a union into a join (#930) PR #967
 

datajoint/expression.py

@@ -558,7 +558,7 @@ def create(cls, arg, group, keep_all_rows=False):
         if inspect.isclass(group) and issubclass(group, QueryExpression):
             group = group()   # instantiate if a class
         assert isinstance(group, QueryExpression)
-        if keep_all_rows and len(group.support) > 1:
+        if keep_all_rows and len(group.support) > 1 or group.heading.new_attributes:
             group = group.make_subquery()  # subquery if left joining a join
         join = arg.join(group, left=keep_all_rows)  # reuse the join logic
         result = cls()

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 sql code generation to comply with sql mode ``ONLY_FULL_GROUP_BY`` (#916) PR #965
 * Bugfix - Fix count for left-joined ``QueryExpressions`` (#951) PR #966
 * Bugfix - Fix assertion error when performing a union into a join (#930) PR #967
 

tests/test_aggr_regressions.py

@@ -3,7 +3,7 @@
 """
 
 import itertools
-from nose.tools import assert_equal, raises
+from nose.tools import assert_equal
 import datajoint as dj
 from . import PREFIX, CONN_INFO
 import uuid

tests/test_groupby.py

@@ -0,0 +1,11 @@
+from .schema_simple import A, D
+
+
+def test_aggr_with_proj():
+    # issue #944 - only breaks with MariaDB
+    # MariaDB implements the SQL:1992 standard that prohibits fields in the select statement that are 
+    # not also in the GROUP BY statement.
+    # An improved specification in SQL:2003 allows fields that are functionally dependent on the group by 
+    # attributes to be allowed in the select. This behavior is implemented by MySQL correctly but not MariaDB yet. 
+    # See MariaDB issue: https://jira.mariadb.org/browse/MDEV-11588
+    A.aggr(D.proj(m='id_l'), ..., n='max(m) - min(m)')