def __get_or_create_database(self, doc_client, id) -> str:
<EOL>dbs = list(doc_client.QueryDatabases({<EOL>"<STR_LIT>": "<STR_LIT>",<EOL>"<STR_LIT>": [<EOL>{"<STR_LIT:name>": "<STR_LIT>", "<STR_LIT:value>": id}<EOL>]<EOL>}))<EOL>if len(dbs) > <NUM_LIT:0>:<EOL><INDENT>return dbs[<NUM_LIT:0>]['<STR_LIT:id>']<EOL><DEDENT>else:<EOL><INDENT>res = doc_client.CreateDatabase({'<STR_LIT:id>': id})<EOL>return res['<STR_LIT:id>']<EOL><DEDENT>
Return the database link.

        Check if the database exists or create the db.

        :param doc_client:
        :param id:
        :return str: