From 3a5b7255adfb7eefbd9a48b56fdb7654b636d7cb Mon Sep 17 00:00:00 2001
From: David Beitey <david@davidjb.com>
Date: Thu, 3 Dec 2020 17:36:47 +1000
Subject: [PATCH] Change UniqueConstraint for wider database support (#6607)
This fixes #6393 by modifying the constraint to use an IN condition
which supports both Postgres and SQL Server. Previously, the `|` (OR)
condition was only supported by Postgres because SQL Server only
supports AND conditions.
The implementation follows suggestions from @gasman in
https://github.com/wagtail/wagtail/issues/6393#issuecomment-732161057:
* Migration 0050 is modified to not break on SQL Server
* Added migration 0060 to add or replace the constraint
Additionally, this allows for and documents a `DATABASE_DRIVER` env
variable to be set for testing, to allow a different SQL Server driver
(e.g. FreeTDS on Mac/Linux); and adds the specific `host_is_server`
option for FreeTDS (won't affect SQL Server Native Client on CI).
---
CHANGELOG.txt | 1 +
docs/contributing/developing.rst | 2 ++
docs/releases/2.12.rst | 1 +
...0050_workflow_rejected_to_needs_changes.py | 2 +-
.../0060_fix_workflow_unique_constraint.py | 21 +++++++++++++++++++
wagtail/core/models.py | 4 ++--
wagtail/tests/settings.py | 3 ++-
7 files changed, 30 insertions(+), 4 deletions(-)
create mode 100644 wagtail/core/migrations/0060_fix_workflow_unique_constraint.py
diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index e2fe6c7e01..1cca4eaa42 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -15,6 +15,7 @@ Changelog
* Fix: Stop menu icon overlapping the breadcrumb on small viewport widths in page editor (Karran Besen)
* Fix: Make sure document chooser pagination preserves the selected collection when moving between pages (Alex Sa)
* Fix: Gracefully handle oEmbed endpoints returning non-JSON responses (Matt Westcott)
+ * Fix: Fix unique constraint on WorkflowState for SQL Server compatibility (David Beitey)
2.11.3 (10.12.2020)
diff --git a/docs/contributing/developing.rst b/docs/contributing/developing.rst
index cc269ed5ce..488b636891 100644
--- a/docs/contributing/developing.rst
+++ b/docs/contributing/developing.rst
@@ -147,6 +147,8 @@ If you need to use different connection settings, use the following environment
* ``DATABASE_PORT``
+It is also possible to set ``DATABASE_DRIVER``, which corresponds to the `driver` value within `OPTIONS` if an SQL Server engine is used.
+
Testing Elasticsearch
---------------------
diff --git a/docs/releases/2.12.rst b/docs/releases/2.12.rst
index 5ddda869d7..dbb06e916f 100644
--- a/docs/releases/2.12.rst
+++ b/docs/releases/2.12.rst
@@ -43,6 +43,7 @@ Bug fixes
* Stop menu icon overlapping the breadcrumb on small viewport widths in page editor (Karran Besen)
* Make sure document chooser pagination preserves the selected collection when moving between pages (Alex Sa)
* Gracefully handle oEmbed endpoints returning non-JSON responses (Matt Westcott)
+ * Fix unique constraint on WorkflowState for SQL Server compatibility (David Beitey)
Upgrade considerations
diff --git a/wagtail/core/migrations/0050_workflow_rejected_to_needs_changes.py b/wagtail/core/migrations/0050_workflow_rejected_to_needs_changes.py
index 747eecbeb2..0178b74b25 100644
--- a/wagtail/core/migrations/0050_workflow_rejected_to_needs_changes.py
+++ b/wagtail/core/migrations/0050_workflow_rejected_to_needs_changes.py
@@ -21,6 +21,6 @@ class Migration(migrations.Migration):
),
migrations.AddConstraint(
model_name='workflowstate',
- constraint=models.UniqueConstraint(condition=models.Q(('status', 'in_progress'), ('status', 'needs_changes'), _connector='OR'), fields=('page',), name='unique_in_progress_workflow'),
+ constraint=models.UniqueConstraint(condition=models.Q(status__in=('in_progress', 'needs_changes')), fields=('page',), name='unique_in_progress_workflow'),
),
]
diff --git a/wagtail/core/migrations/0060_fix_workflow_unique_constraint.py b/wagtail/core/migrations/0060_fix_workflow_unique_constraint.py
new file mode 100644
index 0000000000..cea03cc449
--- /dev/null
+++ b/wagtail/core/migrations/0060_fix_workflow_unique_constraint.py
@@ -0,0 +1,21 @@
+# Generated by Django 3.1.3 on 2020-11-27 01:19
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+ dependencies = [
+ ('wagtailcore', '0059_apply_collection_ordering'),
+ ]
+
+ operations = [
+ migrations.RemoveConstraint(
+ model_name='workflowstate',
+ name='unique_in_progress_workflow',
+ ),
+ migrations.AddConstraint(
+ model_name='workflowstate',
+ constraint=models.UniqueConstraint(condition=models.Q(status__in=('in_progress', 'needs_changes')), fields=('page',), name='unique_in_progress_workflow'),
+ ),
+ ]
diff --git a/wagtail/core/models.py b/wagtail/core/models.py
index a1bec2fd6e..01ffcccdf7 100644
--- a/wagtail/core/models.py
+++ b/wagtail/core/models.py
@@ -4316,9 +4316,9 @@ class WorkflowState(models.Model):
class Meta:
verbose_name = _('Workflow state')
verbose_name_plural = _('Workflow states')
- # prevent multiple STATUS_IN_PROGRESS/STATUS_NEEDS_CHANGES workflows for the same page. This is not supported by MySQL, so is checked additionally on save.
+ # prevent multiple STATUS_IN_PROGRESS/STATUS_NEEDS_CHANGES workflows for the same page. This is only supported by specific databases (e.g. Postgres, SQL Server), so is checked additionally on save.
constraints = [
- models.UniqueConstraint(fields=['page'], condition=(Q(status='in_progress') | Q(status='needs_changes')), name='unique_in_progress_workflow')
+ models.UniqueConstraint(fields=['page'], condition=Q(status__in=('in_progress', 'needs_changes')), name='unique_in_progress_workflow')
]
diff --git a/wagtail/tests/settings.py b/wagtail/tests/settings.py
index 09196de07f..d0df9d3de8 100644
--- a/wagtail/tests/settings.py
+++ b/wagtail/tests/settings.py
@@ -33,8 +33,9 @@ if DATABASES['default']['ENGINE'] != 'django.db.backends.sqlite3':
# Add extra options when mssql is used (on for example appveyor)
if DATABASES['default']['ENGINE'] == 'sql_server.pyodbc':
DATABASES['default']['OPTIONS'] = {
- 'driver': 'SQL Server Native Client 11.0',
+ 'driver': os.environ.get('DATABASE_DRIVER', 'SQL Server Native Client 11.0'),
'MARS_Connection': 'True',
+ 'host_is_server': True, # Applies to FreeTDS driver only
}