For databases I am finding langchain.utilities.SQLDatabase and langchain_experimental.sql.SQLDatabaseChain to be very useful. However their APIs (like SQLDatabase.from_uri, SQLDatabaseChain.from_llm, create_sql_query_chain etc.) seem to be currently taking singleton databases.
Is there a way to run such analysis / SQL queries across multiple databases (e.g. chaining these single db langchains etc.) or are there any plans to push such mechanism down in the framework by extending these APIs to take say a list of DBs?
The framework / LangChain can then construct the SQL schema across multiple databases, qualifying tables by corresponding databases they are in. It can then pass such a schema down to LLMs who can then handle it.
Note that I am referring only to databases on the same server.