Alembic migrations for multiple schemas with identical models

[MahmudulHassan5809]

I have a PostgreSQL database with multiple schemas, and each schema has the same set of models (same tables/columns).

In my application, I generate Alembic migrations from these models. Since the models are the same across schemas, I want the migration files to contain a placeholder for the schema name instead of hardcoding one schema.

At runtime, when I run alembic upgrade, I want to pass the target schema name through an environment variable (e.g., TENANT_SCHEMA=mytenant) so the migration is applied to that specific schema.

So the workflow I’m looking for is:
Generate migration files once (schema-agnostic).
Use alembic upgrade with an environment variable to apply those migrations to any schema I choose.

Question:
What’s the best practice or recommended way to configure Alembic to:
Generate schema-agnostic migrations (with a placeholder for schema name).
Apply those migrations dynamically to a schema specified at runtime via an environment variable.

[CaselIT]

Hi,

To provide the arguments to alembic, you can use either of

• https://alembic.sqlalchemy.org/en/latest/api/runtime.html#alembic.runtime.environment.EnvironmentContext.get_tag_argument
• https://alembic.sqlalchemy.org/en/latest/api/runtime.html#alembic.runtime.environment.EnvironmentContext.get_x_argument

You can also refer to https://alembic.sqlalchemy.org/en/latest/cookbook.html#rudimental-schema-level-multi-tenancy-for-postgresql-mysql-other-databases for an example
and to the multidb template https://github.com/sqlalchemy/alembic/tree/main/alembic/templates/multidb for an example of how to pass customer parameter to upgrade and downgrade functions (that in your case could the schema, as an alternative to the example in the cookbook)

[MahmudulHassan5809]

Thanks for reply .
https://alembic.sqlalchemy.org/en/latest/cookbook.html#rudimental-schema-level-multi-tenancy-for-postgresql-mysql-other-databases
following this doc i solve the my problem .