we don't support order by in union, fix #16 #15 #14

Author: gijzelaerr

sqlalchemy_monetdb/requirements.py

@@ -104,5 +104,39 @@ def bound_limit_offset(self):
         open by default, but closed since raises:
 
         sqlalchemy.exc.CompileError: This SELECT structure does not use a simple integer value for offset
+        """
+        return exclusions.closed()
+
+    @property
+    def parens_in_union_contained_select_w_limit_offset(self):
+        """Target database must support parenthesized SELECT in UNION
+        when LIMIT/OFFSET is specifically present.
+
+        E.g. (SELECT ...) UNION (SELECT ..)
+
+        This is known to fail on SQLite.
+
+        This is also unsupported by MonetDB
+
+        https://www.monetdb.org/bugzilla/show_bug.cgi?id=6434
+
+        """
+        return exclusions.closed()
+
+    @property
+    def parens_in_union_contained_select_wo_limit_offset(self):
+        """Target database must support parenthesized SELECT in UNION
+        when OFFSET/LIMIT is specifically not present.
+
+        E.g. (SELECT ... LIMIT ..) UNION (SELECT .. OFFSET ..)
+
+        This is known to fail on SQLite.  It also fails on Oracle
+        because without LIMIT/OFFSET, there is currently no step that
+        creates an additional subquery.
+
+        This is also unsupported by MonetDB
+
+        https://www.monetdb.org/bugzilla/show_bug.cgi?id=6434
+
         """
         return exclusions.closed()

test/test_suite.py

@@ -1,6 +1,7 @@
 import sqlalchemy as sa
 from sqlalchemy.testing.suite import *
 from sqlalchemy.testing.suite import ComponentReflectionTest as _ComponentReflectionTest
+from sqlalchemy.testing.suite import CompoundSelectTest as _CompoundSelectTest
 from sqlalchemy import inspect
 from sqlalchemy.testing import eq_
 from sqlalchemy import testing
@@ -125,4 +126,18 @@ def define_reflected_tables(cls, metadata, schema):
         if testing.requires.view_column_reflection.enabled:
             cls.define_views(metadata, schema)
         if not schema and testing.requires.temp_table_reflection.enabled:
-            cls.define_temp_tables(metadata)
+            cls.define_temp_tables(metadata)
+
+
+class CompoundSelectTest(_CompoundSelectTest):
+    """
+    Disable tests here since we don't support order by within unions
+
+    https://www.monetdb.org/bugzilla/show_bug.cgi?id=6434
+    """
+
+    def test_distinct_selectable_in_unions(self):
+        pass
+
+    def test_limit_offset_aliased_selectable_in_unions(self):
+        pass