db-migrator 0.1.0

Python package to migrate postgresql database

generate

Example usage:

dbmigrator generate add_id_to_users

generates a file called migrations/20151217170514_add_id_to_users.py with content:

def up(cursor):
    # TODO migration code
    pass

def down(cursor):
    # TODO rollback code
    pass

To set the migrations directory using an entry point, in mymodule setup.py:

setup(
    ...
    entry_points={
        'dbmigrator': [
            'migrations_directory = mymodule.main:migrations_directory',
            ],
        },
    )

Important note: For the settings from setup.py to be picked up, before running dbmigrator, first run python setup.py develop or python setup.py install.

Then in mymodule/main.py:

import os

migrations_directory = '{}/sql/migrations'.format(
    os.path.abspath(os.path.dirname(__file__)))

or:

import os

def migrations_directory():
    return '{}/sql/migrations'.format(
        os.path.abspath(os.path.dirname(__file__)))

init

Example usage:

dbmigrator --db-connection-string='postgres://dbuser@localhost/dbname' init

or with a config file, development.ini, that looks like this:

[app:main]
db-connection-string = postgres://dbuser@localhost/dbname

Run the command:

dbmigrator --config=development.ini init

list

Example usage:

$ dbmigrator list
name                      | is applied | date applied
----------------------------------------------------------------------
20151217170514_add_id_to_   True         2016-01-31 00:15:01.692570+01:00
20151218145832_add_karen_   False
20160107200351_blah         False

migrate

Example usage:

With two migrations in the migrations directory,

migrations/20151217170514_add_id_to_users.py:

def up(cursor):
    # TODO migration code
    pass

def down(cursor):
    # TODO rollback code
    pass

and

migrations/20151218145832_add_karen_to_users.py:

def up(cursor):
    cursor.execute('ALTER TABLE users ADD COLUMN karen TEXT')

def down(cursor):
    cursor.execute('ALTER TABLE users DROP COLUMN karen')

To run the migrations:

$ dbmigrator migrate
Running migration 20151217170514 add_id_to_users

Running migration 20151218145832 add_karen_to_users
---
+++
@@ -4005,21 +4005,22 @@
     first_name text,
     firstname text,
     last_name text,
     surname text,
     full_name text,
     fullname text,
     suffix text,
     title text,
     email text,
     website text,
-    is_moderated boolean
+    is_moderated boolean,
+    karen text
 );

 ALTER TABLE public.users OWNER TO rhaptos;

 --
 -- Name: abstractid; Type: DEFAULT; Schema: public; Owner: rhaptos
 --

 ALTER TABLE ONLY abstracts ALTER COLUMN abstractid SET DEFAULT nextval('abstracts_abstractid_seq'::regclass);

or to run migrations up to a specific version:

$ dbmigrator migrate version=20151217170514
Running migration 20151217170514 add_id_to_users

if all migrations have already been run:

$ dbmigrator migrate
No pending migrations.  Database is up to date.

rollback

Example usage:

With two migrations in the migrations directory,

migrations/20151217170514_add_id_to_users.py:

def up(cursor):
    # TODO migration code
    pass

def down(cursor):
    # TODO rollback code
    pass

and

migrations/20151218145832_add_karen_to_users.py:

def up(cursor):
    cursor.execute('ALTER TABLE users ADD COLUMN karen TEXT')

def down(cursor):
    cursor.execute('ALTER TABLE users DROP COLUMN karen')

Make sure the database is up to date:

$ dbmigrator migrate
No pending migrations.  Database is up to date.

Now rollback the last migration:

$ dbmigrator rollback
Rolling back migration 20151218145832 add_karen_to_users
---
+++
@@ -4005,22 +4005,21 @@
     first_name text,
     firstname text,
     last_name text,
     surname text,
     full_name text,
     fullname text,
     suffix text,
     title text,
     email text,
     website text,
-    is_moderated boolean,
-    karen text
+    is_moderated boolean
 );

 ALTER TABLE public.users OWNER TO rhaptos;

 --
 -- Name: abstractid; Type: DEFAULT; Schema: public; Owner: rhaptos
 --

 ALTER TABLE ONLY abstracts ALTER COLUMN abstractid SET DEFAULT nextval('abstracts_abstractid_seq'::regclass);

To rollback the last 2 migrations:

$ dbmigrator rollback --steps=2
Rolling back migration 20151218145832 add_karen_to_users
---
+++
@@ -4005,22 +4005,21 @@
     first_name text,
     firstname text,
     last_name text,
     surname text,
     full_name text,
     fullname text,
     suffix text,
     title text,
     email text,
     website text,
-    is_moderated boolean,
-    karen text
+    is_moderated boolean
 );

 ALTER TABLE public.users OWNER TO rhaptos;

 --
 -- Name: abstractid; Type: DEFAULT; Schema: public; Owner: rhaptos
 --

 ALTER TABLE ONLY abstracts ALTER COLUMN abstractid SET DEFAULT nextval('abstracts_abstractid_seq'::regclass);

Rolling back migration 20151217170514 add_id_to_users

---

CHANGELOG

0.1.0 (2016-02-12)

• Allow multiple migrations directories / context to be specified

• Add –verbose which prints the configuration used by dbmigrator

• Use datetime utcnow instead of now for timestamps

• Add --version to show the version of db-migrator installed

0.0.7 (2016-02-10)

• Add option --context to dbmigrator in order to load entry points

• Raise error if config file is specified but not found

0.0.6 (2016-02-08)

• Fix missing migrations directory the “init” command

0.0.5 (2016-02-08)

• Include CHANGELOG in distribution’s manifest

0.0.4 (2016-02-08)

• Show warning message instead of error if migrations directory is undefined

• Add CHANGELOG

0.0.3 (2016-02-08)

• Return error if migrations directory is undefined

0.0.2 (2016-02-03)

• Fix invalid rst in README

• Update setup.py description and long_description

• Update setup.py to include README as the description and fix url

• Update README and cli after removing default value for config file

• Remove default config path (development.ini)

• Add dbmigrator list command

• Fix dbmigrator rollback to stop if there are no migrations to rollback

• Print message after initializing schema migrations

• Add note to run python setup.py install if using entry points

• Add migrations directory setting from setup.py entry point in README

• Update command names for init and generate in README

• Get settings from setup.py entry points

• Remove __init__.py generation in migrations directory

• Add option version to dbmigrator init for setting the initial version

• Rename “generate_migration” command to “generate”

• Rename “init_schema_migrations” command to “init”

• Change the way migrations are imported so it works in python2

• Add “applied” timestamp to schema migrations table

• Add # -*- coding: utf-8 -*- to the top of generated migration files

• Add README

• Add command “rollback” to rollback migrations

• Add command “migrate” to run pending migrations

• Add migrations to table when running init_schema_migrations

• Add command for creating the schema migrations table

• Create dbmigrator cli and “generate_migration” command

• Create dbmigrator python package