Implement placeholders for CUBE, ROLLUP, GROUPING SETSreview/mike_bayer/pr_github_383

Fixes: #3429

Co-authored-by: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: I870ee7dc801d553c5309c291402ec468b671e9a9
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/383

1 files changed, 62 insertions, 0 deletions

diff --git a/lib/sqlalchemy/sql/functions.py b/lib/sqlalchemy/sql/functions.py
index 08f1d32a5..9a9396fec 100644
--- a/lib/sqlalchemy/sql/functions.py
+++ b/lib/sqlalchemy/sql/functions.py
@@ -811,3 +811,65 @@ class cume_dist(GenericFunction):
 
     """
     type = sqltypes.Numeric()
+
+
+class cube(GenericFunction):
+    r"""Implement the ``CUBE`` grouping operation.
+
+    This function is used as part of the GROUP BY of a statement,
+    e.g. :meth:`.Select.group_by`::
+
+        stmt = select(
+            [func.sum(table.c.value), table.c.col_1, table.c.col_2]
+            ).group_by(func.cube(table.c.col_1, table.c.col_2))
+
+    .. versionadded:: 1.2
+
+    """
+
+
+class rollup(GenericFunction):
+    r"""Implement the ``ROLLUP`` grouping operation.
+
+    This function is used as part of the GROUP BY of a statement,
+    e.g. :meth:`.Select.group_by`::
+
+        stmt = select(
+            [func.sum(table.c.value), table.c.col_1, table.c.col_2]
+        ).group_by(func.rollup(table.c.col_1, table.c.col_2))
+
+    .. versionadded:: 1.2
+
+    """
+
+
+class grouping_sets(GenericFunction):
+    r"""Implement the ``GROUPING SETS`` grouping operation.
+
+    This function is used as part of the GROUP BY of a statement,
+    e.g. :meth:`.Select.group_by`::
+
+        stmt = select(
+            [func.sum(table.c.value), table.c.col_1, table.c.col_2]
+        ).group_by(func.grouping_sets(table.c.col_1, table.c.col_2))
+
+    In order to group by multiple sets, use the :func:`.tuple_` construct::
+
+        from sqlalchemy import tuple_
+
+        stmt = select(
+            [
+                func.sum(table.c.value),
+                table.c.col_1, table.c.col_2,
+                table.c.col_3]
+        ).group_by(
+            func.grouping_sets(
+                tuple_(table.c.col_1, table.c.col_2),
+                tuple_(table.c.value, table.c.col_3),
+            )
+        )
+
+
+    .. versionadded:: 1.2
+
+    """