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https://github.com/booqoffsky/neo4j-python-migrations
A database migration tool for Neo4j that allows to apply Cypher-based and arbitrary Python-based migrations.
https://github.com/booqoffsky/neo4j-python-migrations
migrations neo4j python
Last synced: about 1 month ago
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A database migration tool for Neo4j that allows to apply Cypher-based and arbitrary Python-based migrations.
- Host: GitHub
- URL: https://github.com/booqoffsky/neo4j-python-migrations
- Owner: booqoffsky
- License: mit
- Created: 2022-10-25T19:45:51.000Z (about 2 years ago)
- Default Branch: main
- Last Pushed: 2024-06-07T21:09:16.000Z (7 months ago)
- Last Synced: 2024-10-09T09:48:36.332Z (3 months ago)
- Topics: migrations, neo4j, python
- Language: Python
- Homepage:
- Size: 60.5 KB
- Stars: 4
- Watchers: 1
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
[](https://pypi.org/project/neo4j-python-migrations/)
# neo4j-python-migrations
> It is a database migration tool for [Neo4j](http://neo4j.com) written in Python
> that allows to apply not only Cypher migrations, but also arbitrary Python-based migrations.
>
> This tool is inspired by [Michael Simons tool for Java](https://github.com/michael-simons/neo4j-migrations)
> and works directly on [neo4j-python-driver](https://github.com/neo4j/neo4j-python-driver).
# Features
- Python migration support makes it possible to do any things in your migration that Python allows you to do.
- Cypher-based migrations support.
- It can be used either via the command line or directly in your code.
- Multi-database support for Neo4j Enterprise Edition users.
- The ability to separate logically independent migration chains within a single database (see the `project` option).
May be useful for Neo4j Community Edition users.
# Installation
From PyPi:
`pip3 install neo4j-python-migrations`
If you want to install it from sources, try this:
```
python3 -m pip install poetry
python3 -m pip install .
python3 -m neo4j_python_migrations
```
# Usage
## Creating migrations
### Naming Convention
Each migration will be a Cypher or Python file following the format `V__.ext`.
Make sure to follow the naming convention as stated in
[Michael's tool documentation](https://michael-simons.github.io/neo4j-migrations/current/#concepts_naming-conventions)
(except that .py files are allowed).
### Cypher
Just create a Cypher file with your custom script, for example `./migrations/V0001__initial.cypher`:
```
CREATE CONSTRAINT UniqueAuthor IF NOT EXISTS ON (a:AUTHOR) ASSERT a.uuid IS UNIQUE;
CREATE INDEX author_uuid_index IF NOT EXISTS FOR (a:AUTHOR) ON (a.uuid);
```
This script will be executed within a single transaction.
Therefore, if you need both DDL and DML commands, split them into different files.
### Python
Python-based migrations should have a special format, for example `./migrations/V0002__drop_index.py`:
```
from neo4j import Transaction
# This function must be present
def up(tx: Transaction):
tx.run("DROP INDEX author_uuid_index")
```
## Applying migrations
### CLI
You can apply migrations or verify the status of migrations using the command line interface:
```
Usage: python -m neo4j_python_migrations [OPTIONS] COMMAND [ARGS]...
Options:
--username TEXT The login of the user connecting to the
database. [env var: NEO4J_MIGRATIONS_USER;
default: neo4j]
--password TEXT The password of the user connecting to the
database. [env var: NEO4J_MIGRATIONS_PASS;
default: neo4j]
--path PATH The path to the directory for scanning
migration files. [env var:
NEO4J_MIGRATIONS_PATH; required]
--port INTEGER Port for connecting to the database [env
var: NEO4J_MIGRATIONS_PORT; default: 7687]
--host TEXT Host for connecting to the database [env
var: NEO4J_MIGRATIONS_HOST; default:
127.0.0.1]
--scheme TEXT Scheme for connecting to the database
[default: neo4j]
--project TEXT The name of the project for separating
logically independent migration chains
within a single database. [env var:
NEO4J_MIGRATIONS_PROJECT]
--schema-database TEXT The database that should be used for storing
information about migrations (Neo4j EE). If
not specified, then the database that should
be migrated is used. [env var:
NEO4J_MIGRATIONS_SCHEMA_DATABASE]
--database TEXT The database that should be migrated (Neo4j
EE) [env var: NEO4J_MIGRATIONS_DATABASE]
--install-completion [bash|zsh|fish|powershell|pwsh]
Install completion for the specified shell.
--show-completion [bash|zsh|fish|powershell|pwsh]
Show completion for the specified shell, to
copy it or customize the installation.
--help Show this message and exit.
Commands:
analyze Analyze migrations, find pending and missed.
migrate Retrieves all pending migrations, verify and applies them.
```
So, to apply migrations, just run the command:
`python3 -m neo4j_python_migrations --username neo4j --password test --path ./migrations migrate`
_Note: it is more secure to store the password in the environment variable NEO4J_MIGRATIONS_PASS._
### Python Code
You can apply migrations directly into your application:
```
from pathlib import Path
from neo4j import GraphDatabase
from neo4j_python_migrations.executor import Executor
with GraphDatabase.driver("neo4j://localhost:7687", auth=("neo4j", "test")) as driver:
executor = Executor(driver, migrations_path=Path("./migrations"))
executor.migrate()
```
Available methods: `migrate`, `analyze`.
# How migrations are tracked
Information about the applied migrations is stored in the database using the schema
described in [Michael's README](https://michael-simons.github.io/neo4j-migrations/current/#concepts_chain).
Supported migration types: СYPHER, PYTHON. Other types of migrations, such as JAVA, are not supported.
Note: the `project` option are incompatible with this schema.
When using the option, each migration nodes will have an additional property named `project`.