id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
28849	SQLite foreign key constraints are not repointed on model or field rename	Simon Charette	nobody	"SQLite foreign key constraints are not automatically repointed on table or column renames which is going to cause a issues to projects who previously renamed a model or a column referenced by another model when they migrate to Django 2.0 which start enforcing them.

e.g. of a SQLite3 session

{{{#!sql
SQLite version 3.11.0 2016-02-15 17:29:24
Enter "".help"" for usage hints.
Connected to a transient in-memory database.
Use "".open FILENAME"" to reopen on a persistent database.
sqlite> CREATE TABLE foo (""id"" integer NOT NULL PRIMARY KEY AUTOINCREMENT);
sqlite> CREATE TABLE bar (""id"" integer NOT NULL PRIMARY KEY AUTOINCREMENT, ""foo_id"" integer NOT NULL REFERENCES ""foo"" (""id"") DEFERRABLE INITIALLY DEFERRED);
sqlite> ALTER TABLE foo RENAME TO renamed;
sqlite> .schema bar
CREATE TABLE bar (""id"" integer NOT NULL PRIMARY KEY AUTOINCREMENT, ""foo_id"" integer NOT NULL REFERENCES ""foo"" (""id"") DEFERRABLE INITIALLY DEFERRED);  -- It still points to ""foo""
sqlite> INSERT INTO bar (foo_id) VALUES (999);
sqlite> PRAGMA foreign_keys = ON; -- From Django 2.0+
sqlite> INSERT INTO bar (foo_id) VALUES (999);
Error: no such table: main.foo
}}}

Since we're already documenting that [https://docs.djangoproject.com/en/2.0/releases/2.0/#foreign-key-constraints-are-now-enabled-on-sqlite users should remake their tables] it should alleviate the issue but we should also sure to:

1. Document that tables that have been previously renamed (or had a column referenced by a `ForeignKey(to_field)` renamed) ''must'' be rebuilt.
2. Adjust SQLite's schema editor to remake tables referencing a renamed table or one that is remade to simulate a column rename to prevent this from happening from now on.

This was discovered while working on fixing #25817."	Bug	closed	Migrations	2.0	Release blocker	fixed			Ready for checkin	1	0	0	0	0	0