Preview alembic dialect fails with alembic > 1.6

[kasium]

Creating a table fails with alembic > 1.6 and SA > 1.4

tests/conftest.py:116: in create_database_content
    command.upgrade(config, revision="head")
venv/lib/python3.7/site-packages/alembic/command.py:294: in upgrade
    script.run_env()
venv/lib/python3.7/site-packages/alembic/script/base.py:490: in run_env
    util.load_python_file(self.dir, "env.py")
venv/lib/python3.7/site-packages/alembic/util/pyfiles.py:97: in load_python_file
    module = load_module_py(module_id, path)
venv/lib/python3.7/site-packages/alembic/util/compat.py:182: in load_module_py
    spec.loader.exec_module(module)
my_project/migration/env.py:61: in <module>
    run_migrations_online()
my_project/migration/env.py:51: in run_migrations_online
    context.run_migrations()
venv/lib/python3.7/site-packages/alembic/runtime/environment.py:813: in run_migrations
    self.get_context().run_migrations(**kw)
venv/lib/python3.7/site-packages/alembic/runtime/migration.py:561: in run_migrations
    step.migration_fn(**kw)
my_project/migration/versions/f1894d2b7029_create_service_tables.py:26: in upgrade
    hana_table_type="COLUMN",
venv/lib/python3.7/site-packages/alembic/operations/ops.py:1072: in create_table
    return operations.invoke(op)
venv/lib/python3.7/site-packages/alembic/operations/base.py:354: in invoke
    return fn(self, operation)
venv/lib/python3.7/site-packages/alembic/operations/toimpl.py:101: in create_table
    operations.impl.create_table(table)
venv/lib/python3.7/site-packages/alembic/ddl/impl.py:277: in create_table
    self._exec(schema.CreateTable(table))
venv/lib/python3.7/site-packages/alembic/ddl/impl.py:146: in _exec
    return conn.execute(construct, multiparams)
venv/lib/python3.7/site-packages/sqlalchemy/engine/base.py:1262: in execute
    return meth(self, multiparams, params, _EMPTY_EXECUTION_OPTS)
venv/lib/python3.7/site-packages/sqlalchemy/sql/ddl.py:78: in _execute_on_connection
    self, multiparams, params, execution_options
venv/lib/python3.7/site-packages/sqlalchemy/engine/base.py:1350: in _execute_ddl
    dialect=dialect, schema_translate_map=schema_translate_map
venv/lib/python3.7/site-packages/sqlalchemy/sql/elements.py:522: in compile
    return self._compiler(dialect, **kw)
venv/lib/python3.7/site-packages/sqlalchemy/sql/ddl.py:29: in _compiler
    return dialect.ddl_compiler(dialect, self, **kw)
venv/lib/python3.7/site-packages/sqlalchemy/sql/compiler.py:455: in __init__
    self.string = self.process(self.statement, **compile_kwargs)
venv/lib/python3.7/site-packages/sqlalchemy/sql/compiler.py:490: in process
    return obj._compiler_dispatch(self, **kwargs)
venv/lib/python3.7/site-packages/sqlalchemy/sql/visitors.py:81: in _compiler_dispatch
    return meth(self, **kw)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

 

self = <sqlalchemy_hana.dialect.HANADDLCompiler object at 0x7fb4fcabf438>, create = <sqlalchemy.sql.ddl.CreateTable object at 0x7fb4fcabf3c8>

 

    def visit_create_table(self, create):
        table = create.element
    
        # The table._prefixes list outlives the current compilation, meaning changing the list
        # will change it globally. To prevent adding the same prefix multiple times, it is
        # removed again after the super-class'es visit_create_table call, which consumes the
        # table prefixes.
    
        table_type = table.kwargs.get('hana_table_type')
        appended_index = None
        if table_type:
>           appended_index = len(table._prefixes)
E           TypeError: object of type 'NoneType' has no len()

 

venv/lib/python3.7/site-packages/sqlalchemy_hana/dialect.py:169: TypeError

[kasium]

See sqlalchemy/alembic#867

[kasium]

Moved to https://github.com/SAP/sqlalchemy-hana/issues/102