Pydantic triggers extra queries after parse_obj_as, is this normal?

[dlopes7]

I'm trying to use pydantic with sqlalchemy in a fastapi project.

My "stocks object" is:

db.query(Stock).join(QuarterIncomeStatement).limit(10).all()

This triggers a query, as expected, like so:

SELECT stocks.ticker AS stocks_ticker, .....  FROM stocks JOIN quarter_income_statements ON stocks.ticker = quarter_income_statements.ticker LIMIT %(param_1)s

And I am returning the objects with:

parse_obj_as(List[Stock], stocks)

The parse_obj_as method call triggers extra queries to run against my database, in the format below, the number of extra queries depends on the number of stocks returned.

SELECT quarter_income_statements.ticker AS quarter_income_statements_ticker, .... FROM quarter_income_statements WHERE %(param_1)s = quarter_income_statements.ticker

Anyone know why is this the case? I did not know that this cast could cause SQL Alchemy to run extra queries. I don' t think this is an issue, so I am opening a discussion to see if I can make this work with a single query

[dlopes7]

This can be deleted, it has nothing to do with pydantic, but with fastapi response model