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Ticket #2061 (closed: fixed)

Opened 2 years ago

Last modified 2 years ago

[patch] PostgreSQL index introspection fails on tables that have dropped columns

Reported by: Chris Chamberlin <dja@cdc.msbx.net> Assigned to: adrian
Milestone: Component: Database wrapper
Version: SVN Keywords:
Cc: Triage Stage: Unreviewed
Has patch: 1 Needs documentation: 0
Needs tests: 0 Patch needs improvement: 0

Description

When building models from an existing PostgreSQL database, python manage.py inspectdb fails if the table being inspected has had columns that were created and then dropped before inspection.

Traceback (most recent call last):
  File "manage.py", line 11, in ?
    execute_manager(settings)
  File "/usr/lib/python2.3/site-packages/django/core/management.py", line 1250
, in execute_manager
    execute_from_command_line(action_mapping)
  File "/usr/lib/python2.3/site-packages/django/core/management.py", line 1179
, in execute_from_command_line
    for line in action_mapping[action]():
  File "/usr/lib/python2.3/site-packages/django/core/management.py", line 716,
 in inspectdb
    indexes = introspection_module.get_indexes(cursor, table_name)
  File "/usr/lib/python2.3/site-packages/django/db/backends/postgresql/introsp
ection.py", line 67, in get_indexes
    col_name = desc[int(row[0])-1][0]
IndexError: tuple index out of range

The problem is that when a column is dropped, PostgreSQL doesn't actually remove it from the pg_catalog.pg_attribute table, which the pg_catalog.pg_index.indkey column references; instead, it just renames them to something like "...pg.dropped.4...". The pgsql driver then leaves that column out of its column list, but this means you can't index into an array of columns using the indkey field.

I'll attach a patch that fixes get_indexes() by joining in the indexed column names in the main query. This is tested with PostgreSQL 7.4.8; I don't have access to 8.x. Also, I assume django/db/backends/postgresql_psycopg2/introspection.py should get the same patch.

Attachments

pgsql_introspection_droppedcolumns.diff (2.0 kB) - added by Chris Chamberlin <dja@cdc.msbx.net> on 06/01/06 11:13:14.
patch of django/db/backends/postgresql/introspection.py

Change History

06/01/06 11:13:14 changed by Chris Chamberlin <dja@cdc.msbx.net>

  • attachment pgsql_introspection_droppedcolumns.diff added.

patch of django/db/backends/postgresql/introspection.py

06/01/06 11:17:39 changed by anonymous

  • summary changed from PostgreSQL index introspection fails on tables that have dropped columns to [patch] PostgreSQL index introspection fails on tables that have dropped columns.

06/01/06 11:27:43 changed by adrian

  • status changed from new to closed.
  • resolution set to fixed.

(In [3047]) Fixed #2061 -- Fixed PostgreSQL index introspection in tables that have dropped columns. Thanks, Chris Chamberlin


Add/Change #2061 ([patch] PostgreSQL index introspection fails on tables that have dropped columns)




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