Of course I have working knowledge of SQL, that's how I used MySQL back when we had to write things by hand. I just don't have a working knowledge of JOINs. I could look up the syntax if I needed to use it. [Looks it up] Looks easy enough.
There are numerous SQL commands most users of SQL would probably need to look up.
Arbitrarily deciding that having not-used X means you don't have a working knowledge is a fallacy. Someone else could arbitrarily decide the litmus test is stored procedures. MySQL didn't have those, so instead of using them we had to code at the application layer, and just happened to use application logic in places of JOINs as well.
I don't even remember if MySQL had joins, or non-buggy joins, a dozen years ago. Other people would say, "it doesn't have transactions, so it's not a real database", et cetera, et cetera. You work around limitations and get used to doing things a certain way.
You can have working knowledge of e.g. calculus but need to look things up because you haven't memorized everything yet, and can learn some new method quickly. Someone without working knowledge would simply be lost, no matter what cheat sheets you put in front of them.
To be honest, I don't understand how you manage not writing joins even if your ORM is perfect and flawless. I use the SQL prompt like an interactive debugger, writing queries to look at the internal state of my database.
(I assume that the original post refers to applicants that listed "SQL" somewhere on their resume, or else he wouldn't be asking SQL syntax questions -- I hold that if you have "SQL" on your resume, you had better know how to write a join.)