Opened 2 years ago

Last modified 20 months ago

#25243 new Bug

inspectdb crashes if SQLite foreign key references sqlite_master

Reported by: Stephan Sokolow Owned by: nobody
Component: Core (Management commands) Version: 1.8
Severity: Normal Keywords:
Cc: dina.paolo@… Triage Stage: Accepted
Has patch: no Needs documentation: no
Needs tests: no Patch needs improvement: no
Easy pickings: no UI/UX: no

Description

While trying to import an SQLite database from an old legacy codebase, I ran up against the following exception in Django 1.8.3:

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:

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:

REFERENCES sqlite_master (tbl_name) ON DELETE RESTRICT ON UPDATE CASCADE

At the very least, it should probably have a clearer error message.

Change History (3)

comment:1 Changed 2 years ago by Stephan Sokolow

Oh, please note that I'll have to manually check this for updates as this Trac installation requires some kind of authentication to access RSS feeds.

(After many bad experiences with leaks to spammers, I've learned to not trust Trac installations with my e-mail aliases.)

comment:2 Changed 2 years ago by Tim Graham

Triage Stage: UnreviewedAccepted

comment:3 Changed 20 months ago by Paolo Dina

Cc: dina.paolo@… added
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