Dependency on DB tables

[kpsherva]

Package version (if known): v1.0.0a21

Describe the bug

On the attempt of recreating the db:

psycopg2.errors.DependentObjectsStillExist: cannot drop table files_bucket because other objects depend on it
DETAIL:  constraint fk_records_buckets_bucket_id_files_bucket on table records_buckets depends on table files_bucket
HINT:  Use DROP ... CASCADE to drop the dependent objects too.


The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/opt/rh/rh-python36/root/usr/bin/invenio", line 8, in <module>
    sys.exit(cli())
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 829, in __call__
    return self.main(*args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/flask/cli.py", line 586, in main
    return super(FlaskGroup, self).main(*args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 782, in main
    rv = self.invoke(ctx)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 1259, in invoke
    return _process_result(sub_ctx.command.invoke(sub_ctx))
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 1289, in invoke
    rv.append(sub_ctx.command.invoke(sub_ctx))
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 1066, in invoke
    return ctx.invoke(self.callback, **ctx.params)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/decorators.py", line 21, in new_func
    return f(get_current_context(), *args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/flask/cli.py", line 426, in decorator
    return __ctx.invoke(f, *args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/click/core.py", line 610, in invoke
    return callback(*args, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib/python3.6/site-packages/invenio_db/cli.py", line 74, in drop
    table.drop(bind=_db.engine, checkfirst=True)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/sql/schema.py", line 939, in drop
    bind._run_visitor(ddl.SchemaDropper, self, checkfirst=checkfirst)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 2095, in _run_visitor
    conn._run_visitor(visitorcallable, element, **kwargs)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1656, in _run_visitor
    visitorcallable(self.dialect, self, **kwargs).traverse_single(element)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/sql/visitors.py", line 145, in traverse_single
    return meth(obj, **kw)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/sql/ddl.py", line 1009, in visit_table
    self.connection.execute(DropTable(table))
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1011, in execute
    return meth(self, multiparams, params)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/sql/ddl.py", line 72, in _execute_on_connection
    return connection._execute_ddl(self, multiparams, params)
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1073, in _execute_ddl
    compiled,
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1317, in _execute_context
    e, statement, parameters, cursor, context
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1511, in _handle_dbapi_exception
    sqlalchemy_exception, with_traceback=exc_info[2], from_=e
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/util/compat.py", line 182, in raise_
    raise exception
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/base.py", line 1277, in _execute_context
    cursor, statement, parameters, context
  File "/opt/rh/rh-python36/root/usr/lib64/python3.6/site-packages/sqlalchemy/engine/default.py", line 593, in do_execute
    cursor.execute(statement, parameters)
sqlalchemy.exc.InternalError: (psycopg2.errors.DependentObjectsStillExist) cannot drop table files_bucket because other objects depend on it
DETAIL:  constraint fk_records_buckets_bucket_id_files_bucket on table records_buckets depends on table files_bucket
HINT:  Use DROP ... CASCADE to drop the dependent objects too.