PDO Query Nuance: UPDATE WHERE IN Only Updates One Row

I prefer to always use parameterized queries in PDO when possible. Just now, I encountered a situation in which the complications of using them would have not even been worth it. Take a look at this query:

Given that the post_id‘s exist, this will set a deleted flag on all of them right? Ok, let’s try to define that query using PDO and prepared statements…

As it turns out, that will ONLY update the first row. Turns out, the IN clause is a little more complicated than I thought with prepared statements. There is a proposed solution here, but in my case, the data is not user input and can thus sanitize it myself.