Summary

alembic is a lightweight database migration tool for SQLAlchemy, used to version-control your database schema and apply incremental changes over time. You generate revision scripts that describe schema changes, then upgrade or downgrade a database between those versions. It's the standard way to evolve a database schema alongside a Python application's code.

Tip: Run 'alembic current' to see which revision a database is on; use -c to point at an alternate config file if your alembic.ini isn't in the current directory.

Description

ALEMBIC

NAME

alembic - lightweight database migration tool for usage with the SQLAlchemy

DESCRIPTION

usage: alembic [-h] [-c CONFIG] [-n NAME] [-x X] [--raiseerr]

{branches, current, downgrade, edit, heads, history, init, list_templates, merge, revision, show, stamp, upgrade} ...

positional arguments:

{branches, current, downgrade, edit, heads, history, init, list_templates, merge, revision, show, stamp, upgrade}

branches

Show current branch points

current

Display the current revision for a database.

downgrade

Revert to a previous version.

	edit		Edit revision script(s) using $EDITOR
	heads		Show current available heads in the script directory

history

List changeset scripts in chronological order.

init

Initialize a new scripts directory.

list_templates

List available templates

merge

Merge two revisions together. Creates a new migration file. .. versionadded:: 0.7.0 .. seealso:: :ref:‘branches‘

revision

Create a new revision file.

	show		Show the revision(s) denoted by the given symbol.
	stamp		’stamp’ the revision table with the given revision; don’t run any migrations.

upgrade

Upgrade to a later version.

optional arguments:

-h, --help

show this help message and exit

-c CONFIG, --config CONFIG

Alternate config file

-n NAME, --name NAME

Name of section in .ini file to use for Alembic config

-x X

Additional arguments consumed by custom env.py scripts, e.g. -x setting1=somesetting -x setting2=somesetting

--raiseerr

Raise a full stack trace on error

Examples

alembic init alembic

Initialize a new migration scripts directory in your project.

alembic revision -m "add users table"

Create a new revision file describing a schema change.

alembic upgrade head

Apply migrations to bring the database up to the latest version.

alembic downgrade -1

Revert the database to the previous version.