Oracle supports the DBMS_SQL package which allows dynamic SQL with describing SQL statement in and out parameters to support fully dynamic SQL. There are much metadata that can be gotten from a SQL statement though, which would require a lot of functions to be implemented for this in MariaDB. My suggestion is instead to create just one statement to describe a prepared SQL statement and that the output of this is a JSON struct that contains all relevant data.

For example:

DECLARE

   sql_desc JSON;

BEGIN

   PREPARE s1 FROM 'SELECT c1 col1, c2 col2 FROM tab1 t1 WHERE col1 > ?';

   DESCRIBE s1 INTO JSON sql_desc;

...

END;

Where the JSON in sql_desc describes the returned data:

{"fields": [{"name": "c1", "org_name": "col1", "table": "t1", "org_table": "tab1", "length": 11, "type": "INTEGER"},

{"name": "c2", "org_name": "col2", "table": "t1", "org_table": "tab1", "length": 10, "type": "VARCHAR"}],

"params": {"count": 1}}