#23379: sql_create generates incorrect SQL with synced database
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Reporter: flakfizer | Owner: nobody
Type: Bug | Status: new
Component: Database layer (models, ORM) | Version: 1.7-rc-3
Severity: Normal | Keywords:
Triage Stage: Unreviewed | Has patch: 1
Easy pickings: 0 | UI/UX: 0
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The change between 1.6.6 to 1.7c3 in sql_create's first parameter from
"app" to "app_config" is causing a bug, namely because app.get_models()
returned a list, whereas app_config.get_models() returns a generator.
This causes the "known_models" set to be larger than it should be.
This bug will cause invalid sql - mysql, in my case - to be generated if
tables already exist, as shown in the attached reproduction app.
1) python manage.py repro # generates correct sql
CREATE TABLE `repro_app_a` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`b_id` integer NOT NULL
)
;
CREATE TABLE `repro_app_b` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`a_id` integer NOT NULL
)
;
ALTER TABLE `repro_app_b` ADD CONSTRAINT `a_id_refs_id_4838e71a` FOREIGN
KEY (`a_id`) REFERENCES `repro_app_a` (`id`);
ALTER TABLE `repro_app_a` ADD CONSTRAINT `b_id_refs_id_b49a3179` FOREIGN
KEY (`b_id`) REFERENCES `repro_app_b` (`id`);
2) python manage.py migrate
3) python manage.py repro # generates incorrect sql; the first constraint
fails because table repro_app_b hasn't been created yet.
CREATE TABLE `repro_app_a` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`b_id` integer NOT NULL
)
;
ALTER TABLE `repro_app_a` ADD CONSTRAINT `b_id_refs_id_b49a3179` FOREIGN
KEY (`b_id`) REFERENCES `repro_app_b` (`id`);
CREATE TABLE `repro_app_b` (
`id` integer AUTO_INCREMENT NOT NULL PRIMARY KEY,
`a_id` integer NOT NULL
)
;
ALTER TABLE `repro_app_b` ADD CONSTRAINT `a_id_refs_id_4838e71a` FOREIGN
KEY (`a_id`) REFERENCES `repro_app_a` (`id`);
Fortunately, the (or, "a") fix is an easy one-liner:
diff --git a/django/core/management/sql.py b/django/core/management/sql.py
index 323cb54..048b051 100644
--- a/django/core/management/sql.py
+++ b/django/core/management/sql.py
@@ -36,7 +36,7 @@ def sql_create(app_config, style, connection):
# We trim models from the current app so that the sqlreset command
does not
# generate invalid SQL (leaving models out of known_models is
harmless, so
# we can be conservative).
- app_models = app_config.get_models(include_auto_created=True)
+ app_models = set(app_config.get_models(include_auto_created=True))
final_output = []
tables = connection.introspection.table_names()
known_models = set(model for model in
connection.introspection.installed_models(tables) if model not in
app_models)
--
Ticket URL: <https://code.djangoproject.com/ticket/23379>
Django <https://code.djangoproject.com/>
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