Your, understanding mostly correct but just clarify:

connection.query(sql,value):

• The query string is sent directly to the MySQL server.
• Values are interpolated locally before sending the full query to MySQL.
• Each call is independent; MySQL does not cache or reuse queries.
• Not protected from SQL injection unless manually handled properly.

connection.execute(sql,value):

• MySQL itself prepares the statement (not just locally).
• It sends the query structure first and then parameters separately.
• It prevents SQL injection.
• MySQL caches the prepared statement for reuse within the session.

So, B1 function is the most efficient when running the same query multiple times because connection.prepare sends a single query to MySQL to create a prepared statement and also close after execute query.

B2 function is wasteful because it prepares the statement twice.

B3 function is simple but less efficient than B1 for repeated queries.