diff options
Diffstat (limited to 'test/sql/test_selectable.py')
| -rw-r--r-- | test/sql/test_selectable.py | 51 |
1 files changed, 43 insertions, 8 deletions
diff --git a/test/sql/test_selectable.py b/test/sql/test_selectable.py index a172eb452..b0501c913 100644 --- a/test/sql/test_selectable.py +++ b/test/sql/test_selectable.py @@ -5,7 +5,7 @@ from sqlalchemy import * from sqlalchemy.test import * from sqlalchemy.sql import util as sql_util, visitors from sqlalchemy import exc -from sqlalchemy.sql import table, column +from sqlalchemy.sql import table, column, null from sqlalchemy import util metadata = MetaData() @@ -416,19 +416,54 @@ class ReduceTest(TestBase, AssertsExecutionResults): Column('magazine_page_id', Integer, ForeignKey('magazine_page.page_id'), primary_key=True), ) - from sqlalchemy.orm.util import polymorphic_union - pjoin = polymorphic_union( - { - 'm': page_table.join(magazine_page_table), - 'c': page_table.join(magazine_page_table).join(classified_page_table), - }, None, 'page_join') + # this is essentially the union formed by the ORM's polymorphic_union function. + # we define two versions with different ordering of selects. + + # the first selectable has the "real" column classified_page.magazine_page_id + pjoin = union( + select([ + page_table.c.id, + magazine_page_table.c.page_id, + classified_page_table.c.magazine_page_id + ]).select_from(page_table.join(magazine_page_table).join(classified_page_table)), + + select([ + page_table.c.id, + magazine_page_table.c.page_id, + cast(null(), Integer).label('magazine_page_id') + ]).select_from(page_table.join(magazine_page_table)), + ).alias('pjoin') + eq_( util.column_set(sql_util.reduce_columns([pjoin.c.id, pjoin.c.page_id, pjoin.c.magazine_page_id])), util.column_set([pjoin.c.id]) ) - + + # the first selectable has a CAST, which is a placeholder for + # classified_page.magazine_page_id in the second selectable. reduce_columns + # needs to take into account all foreign keys derived from pjoin.c.magazine_page_id. + # the UNION construct currently makes the external column look like that of the first + # selectable only. + pjoin = union( + select([ + page_table.c.id, + magazine_page_table.c.page_id, + cast(null(), Integer).label('magazine_page_id') + ]).select_from(page_table.join(magazine_page_table)), + select([ + page_table.c.id, + magazine_page_table.c.page_id, + classified_page_table.c.magazine_page_id + ]).select_from(page_table.join(magazine_page_table).join(classified_page_table)) + ).alias('pjoin') + + eq_( + util.column_set(sql_util.reduce_columns([pjoin.c.id, pjoin.c.page_id, pjoin.c.magazine_page_id])), + util.column_set([pjoin.c.id]) + ) + class DerivedTest(TestBase, AssertsExecutionResults): def test_table(self): meta = MetaData() |