Not if your database and driver support placeholders it doesn't. Placeholders pass the data to the db completely unchanged. They do not escape any characters¹. Passing a newline character through a placeholder results in the database receiving a newline character, not the string '\\n' (or the string '\n', for that matter).

Are you perhaps searching for the single-quoted string '\n' (as opposed to the double-quoted string "\n", which is a single newline character, not the two characters \ and n) when putting it into the WHERE clause?

¹ Some drivers may fall back to escaping in order to emulate placeholders for database engines which don't support them - but, in that case, the exact same escaping will be done in the WHERE clause, so it won't affect you anyhow.