DuckDb:Error al usar variables en la funcion mysql_query

An error occurs when launching a MySQL query using DuckDB if a text variable is used. However if it is a number it works correctly.

To launch the query I use the ‘mysql_query’ function of DuckDB. The query that I run is:

SELECT * FROM mysql_query('myattachedbd', "SELECT {{my_var}}")

That query works correctly if my_var is number type. However if my_var is of type text an error occurs, displaying the message:

IO Error: Failed to run query "SELECT ?": You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '?' at line 1

In the preview of the query a correct SQL statement is generated, as shown below:

SELECT 'house'

I hope I have provided enough information to resolve this issue.

Thank you very much