ClickMigrate 1.0.0

A modern, simple database migration framework for ClickHouse.

ClickMigrate

A modern, simple, and reliable database migration framework for ClickHouse, inspired by Alembic.

ClickMigrate is designed to be lightweight and easy to understand. It avoids over-engineered abstractions, offering a straightforward CLI and a clean Python API for managing your ClickHouse schema evolutions.

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Features

• SQL-based Migrations – Write your migrations in plain .sql files.
• Automatic Ordering – Lexicographical sorting ensures migrations run in the correct sequence.
• State Management – Automatically creates and manages a migration history table in ClickHouse.
• Checksum Validation – Validates SHA-256 checksums to detect modified applied migrations.
• Flexible Configuration – Supports pyproject.toml, JSON, YAML, or environment variables.
• Dry-Run Mode – Preview which migrations will be applied without altering the database.
• Python API & CLI – Use ClickMigrate from your terminal or programmatically in Python.

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Installation

ClickMigrate requires Python 3.11+.

Install it using pip:

pip install ClickMigrate

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Quick Start (CLI)

ClickMigrate provides an Alembic-like CLI for managing your migration workflow.

1. Initialize the Environment

Create the migration directory (default: migrations/).

clickmigrate init

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2. Create a Revision

Generate a new sequential SQL migration file.

clickmigrate revision -m "create users table"

Example output:

migrations/
└── 001_create_users_table.sql

Edit the generated file and add your ClickHouse SQL statements.

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3. Check Status

View how many migrations have been applied and how many are pending.

clickmigrate status

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4. Apply Migrations

Run all pending migrations.

clickmigrate migrate

Preview the execution without applying changes:

clickmigrate migrate --dry-run

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5. Validate Migration Integrity

Verify that previously applied migration files have not been modified.

clickmigrate validate

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Configuration

ClickMigrate automatically searches for configuration files in your project root.

Supported formats (in priority order):

1. pyproject.toml (recommended)
2. clickmigrate.json
3. clickmigrate.yaml
4. Environment variables

Option A: pyproject.toml (Recommended)

[tool.clickmigrate]
host = "localhost"
port = 8123
database = "default"
username = "default"
password = "your_secure_password"

migration_directory = "migrations"
migration_table = "clickmigrate_history"

Option B: clickmigrate.json

{
  "host": "localhost",
  "port": 8123,
  "database": "default",
  "username": "default",
  "password": "your_secure_password",
  "migration_directory": "migrations",
  "migration_table": "clickmigrate_history"
}

Option C: clickmigrate.yaml

host: localhost
port: 8123
database: default
username: default
password: your_secure_password

migration_directory: migrations
migration_table: clickmigrate_history

Option D: Environment Variables

CLICKMIGRATE_HOST=localhost
CLICKMIGRATE_PORT=8123
CLICKMIGRATE_DATABASE=default
CLICKMIGRATE_USERNAME=default
CLICKMIGRATE_PASSWORD=your_secure_password

CLICKMIGRATE_MIGRATION_DIRECTORY=migrations
CLICKMIGRATE_MIGRATION_TABLE=clickmigrate_history

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Migration Naming

Migration files are executed in lexicographical order.

Example:

001_create_users.sql
002_add_email.sql
003_create_orders.sql
004_add_indexes.sql

Each migration is executed only once and recorded in the migration history table.

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Commands

Command	Description
clickmigrate init	Initialize a migration project
clickmigrate revision -m "message"	Create a new migration
clickmigrate status	Show migration status
clickmigrate migrate	Apply pending migrations
clickmigrate migrate --dry-run	Preview pending migrations
clickmigrate validate	Validate migration checksums

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Requirements

• Python 3.11+
• A running ClickHouse server
• HTTP interface enabled (default port 8123)

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License

MIT License.