From 6ace54c2601770a0e06418ce5b98c756c86f6a51 Mon Sep 17 00:00:00 2001
From: Goutham Pacha Ravi <gouthampravi@gmail.com>
Date: Wed, 19 May 2021 17:14:24 -0700
Subject: [PATCH] Fix with_entities usage in db queries
In order to retrieve shares with filters
pertaining to separate tables (shares, instances, metadata,
etc), we need to perform joined loads of those
respective database tables as necessary. After the
join, the query cannot select entities due to
Github issue #6253 - The following is an error when
the pattern is used:
sqlalchemy.exc.ArgumentError: Query has only expression-based entities - can't find property named "share_metadata".
sqlalchemy 1.4 has a performance improvement that
delays query processing [2] and disallows this
pattern of usage; we can use a query.count() instead.
In another instance, we can perform joins selectively
only if asked for.
[1] https://github.com/sqlalchemy/sqlalchemy/issues/625
[2] https://docs.sqlalchemy.org/en/14/changelog/migration_14.html#many-core-and-orm-statement-objects-now-perform-much-of-their-construction-and-validation-in-the-compile-phase
Change-Id: I8aa196c171bbc224cec06f517ea22c4e91cbc06a
Closes-Bug: #1926399
Signed-off-by: Goutham Pacha Ravi <gouthampravi@gmail.com>
---
manila/db/sqlalchemy/api.py | 15 ++++++---------
1 file changed, 6 insertions(+), 9 deletions(-)
diff --git a/manila/db/sqlalchemy/api.py b/manila/db/sqlalchemy/api.py
index a71ba7c554..ec4470e955 100644
--- a/manila/db/sqlalchemy/api.py
+++ b/manila/db/sqlalchemy/api.py
@@ -46,7 +46,6 @@ from sqlalchemy import MetaData
from sqlalchemy import or_
from sqlalchemy.orm import joinedload
from sqlalchemy.orm import subqueryload
-from sqlalchemy.sql import distinct
from sqlalchemy.sql.expression import literal
from sqlalchemy.sql.expression import true
from sqlalchemy.sql import func
@@ -2163,8 +2162,7 @@ def _share_get_all_with_filters(context, project_id=None, share_server_id=None,
# NOTE(carloss): Count must be calculated before limit and offset are
# applied into the query.
if show_count:
- count = query.with_entities(
- func.count(distinct(models.Share.id))).scalar()
+ count = query.count()
if 'limit' in filters:
offset = filters.get('offset', 0)
@@ -5266,11 +5264,7 @@ def _share_group_snapshot_get_all(
sort_dir = 'desc'
query = model_query(
- context, models.ShareGroupSnapshot, session=session, read_deleted='no',
- ).options(
- joinedload('share_group'),
- joinedload('share_group_snapshot_members'),
- )
+ context, models.ShareGroupSnapshot, session=session, read_deleted='no')
# Apply filters
if not filters:
@@ -5295,7 +5289,10 @@ def _share_group_snapshot_get_all(
raise exception.InvalidInput(reason=msg)
if detailed:
- return query.all()
+ return query.options(
+ joinedload('share_group'),
+ joinedload('share_group_snapshot_members')
+ ).all()
else:
query = query.with_entities(models.ShareGroupSnapshot.id,
models.ShareGroupSnapshot.name)