alamb commented on issue #10559: URL: https://github.com/apache/datafusion/issues/10559#issuecomment-2127695450
> @alamb - Thanks for responding. This sounds interesting. Could you elaborate on how this can be achieved? > What information gets passed down to SchemaProvider that I can use to determine which TableProvider instance to pass? According to https://docs.rs/datafusion/latest/datafusion/catalog/schema/trait.SchemaProvider.html it gets a table name. > Using a simple example request, "ctx.sql('SELECT * FROM table_a')", how can SchemaProvider return the right TableProvider based on this user request? I don't fully understand your usecase > a generic web service that fetches data through multiple tables/databases depending on the GraphQL request Perhaps you could make something like ```rust let request = ...; // request with graphql context // register a table provider that has access to the context let table = MyTableProvider::new(request) // register `table_` for sql ctx.register_table("table_a", Arc::new(table)) // now accessing table_a from SQL will access a `MyTableProvider` that has access to the request ctx.sql('SELECT * FROM table_a')... ``` You could potentially use a schema provider to avoid having to register all tables for each request, and only instantiate the table providers when they are required -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: github-unsubscr...@datafusion.apache.org For additional commands, e-mail: github-h...@datafusion.apache.org
