DatabaseContext

class felis.db.utils.DatabaseContext(metadata, engine)

Bases: object

Manage the database connection and SQLAlchemy metadata.

Parameters:

• metadata (MetaData) – The SQLAlchemy metadata object.

• engine (Engine | MockConnection) – The SQLAlchemy engine or mock connection object.

Methods Summary

create_all()	Create all tables in the schema using the metadata object.
create_mock_engine(engine_url[, output_file])	Create a mock engine for testing or dumping DDL statements.
drop()	Drop the schema in the database if it exists.
initialize()	Create the schema in the database if it does not exist.

Methods Documentation

create_all()

Create all tables in the schema using the metadata object.

Return type:

None

static create_mock_engine(engine_url, output_file=None)

Create a mock engine for testing or dumping DDL statements.

Parameters:

• engine_url (str | URL) – The SQLAlchemy engine URL.

• output_file (Optional[IO[str]], default: None) – The file to write the SQL statements to. If None, the statements will be written to stdout.

Returns:

The mock connection object.

Return type:

sqlalchemy.engine.mock.MockConnection

drop()

Drop the schema in the database if it exists.

Raises:

ValueError – Raised if the database is not supported.

Return type:

None

Notes

In MySQL, this will drop a database. In PostgreSQL, it will drop a schema. For other variants, this is an unsupported operation.

initialize()

Create the schema in the database if it does not exist.

Raises:

• ValueError – Raised if the database is not supported or it already exists.

• sqlalchemy.exc.SQLAlchemyError – Raised if there is an error creating the schema.

Return type:

None

Notes

In MySQL, this will create a new database and, in PostgreSQL, it will create a new schema. For other variants, this is an unsupported operation.