pgmig 0.0.3

Generate migrations between Postgres databases

Generate migrations between Postgres databases.

Installation

pip install pgmig

Usage

Structure migration

Get the SQL that, when applied to source, makes its structure (tables, extensions, and other object definitions) match target:

import pgmig

sql = pgmig.generate(
    source="postgresql://user:pass@localhost:5432/current",
    target="postgresql://user:pass@localhost:5432/desired",
)

print(sql)  # the migration SQL — run it yourself against `source`

When the two structures already match, generate returns an empty string. pgmig opens read-only connections to both databases and never runs the generated SQL for you.

Contributing

To contribute simply open a PR with your changes, or an issue with your bug/request.

All checks (Linters, type checks and tests) automatically run in CI through GitHub Actions.

Running checks locally

Local development is done with uv.

Start by installing all the development dependencies:

uv sync

To run the linters use pre-commit:

pre-commit run -a

To run the unit tests use pytest:

pytest -c tests/pytest.ini tests

To run type checks use mypy or ty (both are run in CI):

mypy --config-file linters/mypy.toml src tests
ty check --config-file linters/ty.toml src tests

Releasing

To release a new version, run the interactive script:

./scripts/release.py