Python library for creating and applying migrations in ClickHouse database.

Development and Maintenance of large-scale db systems many times requires constant changes to the actual DB system. Holding off the scripts to migrate these will be painful.

• Supports multi statements - more than one query per migration file.
• Allow running migrations out-of-box
• Simple file migrations format: {VERSION}_{name}.sql
• Supports Cluster deployments, makes sure that migrations state is consistent on all cluster nodes

This package originally forked from clickhouse-migrator.

You can install from pypi using pip install clickhouse-migrations.

clickhouse-migrations --db-host localhost \
    --db-user default \
    --db-password secret \
    --db-name test \
    --migrations-dir ./migrations

from clickhouse_migrations.clickhouse_cluster import ClickhouseCluster

cluster = ClickhouseCluster(db_host, db_user, db_password)
cluster.migrate(db_name, migrations_home, cluster_name=None,create_db_if_no_exists=True, multi_statement=True)

The Clickhouse driver does not natively support executing multipe statements in a single query. To allow for multiple statements in a single migration, you can use the multi_statement param. There are two important caveats:

• This mode splits the migration text into separately-executed statements by a semi-colon ;. Thus cannot be used when a statement in the migration contains a string with a semi-colon.
• The queries are not executed in any sort of transaction/batch, meaning you are responsible for fixing partial migrations.