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
25243	inspectdb crashes if SQLite foreign key references sqlite_master	Stephan Sokolow	Sidharth Dusanapudi	"While trying to import an SQLite database from an old legacy codebase, I ran up against the following exception in Django 1.8.3:

{{{
#!sh
ssokolow@monolith XXXXXXX [django] % python manage.py inspectdb >| models.py
Traceback (most recent call last):
  File ""manage.py"", line 10, in <module>
    execute_from_command_line(sys.argv)
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 338, in execute_from_command_line
    utility.execute()
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/__init__.py"", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/base.py"", line 393, in run_from_argv
    self.execute(*args, **cmd_options)
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/base.py"", line 444, in execute
    output = self.handle(*args, **options)
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/commands/inspectdb.py"", line 25, in handle
    for line in self.handle_inspection(options):
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/core/management/commands/inspectdb.py"", line 64, in handle_inspection
    relations = connection.introspection.get_relations(cursor, table_name)
  File ""/home/ssokolow/.virtualenvs/XXXXXXX/local/lib/python2.7/site-packages/django/db/backends/sqlite3/introspection.py"", line 128, in get_relations
    result = cursor.fetchall()[0]
IndexError: list index out of range
}}}

Examining the output revealed that it was dying in a table named ""todos"" and, examing that further, I discovered that inspectdb did '''not''' like what the code was doing to partially enforce a home-built generic foreign key constraint.

Here's the schema which caused it to fail:
{{{
#!sql
CREATE TABLE todos (
    id INTEGER PRIMARY KEY,
    row_id INTEGER,
    table_name VARCHAR(64) DEFAULT 'stories' REFERENCES sqlite_master (tbl_name) ON DELETE RESTRICT ON UPDATE CASCADE COLLATE NOCASE,
    content TEXT NOT NULL CHECK(TRIM(content) <> '' AND TRIM(content) = content AND content NOT LIKE '%  %' AND content NOT GLOB '*[    

]*')
);
}}}

I had to manually dump the database to SQL, edit out this clause in vim (because SQLite's ALTER TABLE is so limited), and then re-create the database before inspectdb would successfully complete:
{{{
#!sql
REFERENCES sqlite_master (tbl_name) ON DELETE RESTRICT ON UPDATE CASCADE
}}}

At the very least, it should probably have a clearer error message."	Bug	assigned	Core (Management commands)	1.8	Normal			dina.paolo@… Sidharth Dusanapudi	Accepted	1	0	0	0	0	0