Postgis migration error after upgrading to Django 1.8

Question

I'm working with a postgres database and the postgis extension. Now, after upgrading to Django 1.8, I'm getting this error while running manage.py migrate:

Traceback (most recent call last):
  File "./manage.py", line 13, in <module>
    execute_from_command_line(sys.argv)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/base.py", line 390, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/base.py", line 441, in execute
    output = self.handle(*args, **options)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 91, in handle
    connection.prepare_database()
  File "/my-project/env/lib/python2.7/site-packages/django/contrib/gis/db/backends/postgis/base.py", line 39, in prepare_database
    cursor.execute("CREATE EXTENSION IF NOT EXISTS postgis")
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/my-project/env/lib/python2.7/site-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 62, in execute
    return self.cursor.execute(sql)
django.db.utils.ProgrammingError: type "spheroid" already exists

Versions

I'm using Postgres.app on OS X

• psql (9.3.4)
• SELECT PostGIS_version(); postgis_version 2.1 USE_GEOS=1 USE_PROJ=1USE_STATS=1
• Django 1.8.2

Answer 1

Ok I solved it.

First I upgraded postgres and postgis with replacing Postgres.app with the newest one and upgrading brew packages. After this, I got the following error:

Traceback (most recent call last):
  File "./manage.py", line 13, in <module>
    execute_from_command_line(sys.argv)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/__init__.py", line 338, in execute_from_command_line
    utility.execute()
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/__init__.py", line 330, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/base.py", line 390, in run_from_argv
    self.execute(*args, **cmd_options)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/base.py", line 441, in execute
    output = self.handle(*args, **options)
  File "/my-project/env/lib/python2.7/site-packages/django/core/management/commands/migrate.py", line 91, in handle
    connection.prepare_database()
  File "/my-project/env/lib/python2.7/site-packages/django/contrib/gis/db/backends/postgis/base.py", line 39, in prepare_database
    cursor.execute("CREATE EXTENSION IF NOT EXISTS postgis")
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 79, in execute
    return super(CursorDebugWrapper, self).execute(sql, params)
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 64, in execute
    return self.cursor.execute(sql, params)
  File "/my-project/env/lib/python2.7/site-packages/django/db/utils.py", line 97, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/my-project/env/lib/python2.7/site-packages/django/db/backends/utils.py", line 62, in execute
    return self.cursor.execute(sql)
django.db.utils.InternalError: PostGIS is already installed in schema 'public', uninstall it first

Then I performed a "Hard Upgrade" as explained here http://postgis.net/docs/manual-2.1/postgis_installation.html#upgrading

All Steps (incl. Hard Upgrade)

1. pg_dump -U $PGUSER -Fc -b -v -f "your_db.backup" your_db
2. psql -U $PGUSER -d postgres -c "DROP DATABASE your_db;"
3. brew uninstall postgresql93 && brew install postgresql or brew upgrade postgresql
4. brew uninstall postgis15 && brew install postgis or brew upgrade postgis
5. Replace Postgres.app with newest one
6. pip uninstall psycopg2 && pip install psycopg2
7. psql -U $PGUSER -d postgres -c "CREATE DATABASE your_db;"
8. psql -U $PGUSER -d your_db -c "CREATE EXTENSION postgis;"
9. /usr/local/share/postgis/postgis_restore.pl your_db.backup | psql -U $PGUSER your_db 2> errors.txt