Which SQL queries are considered complex queries?

Question

SQL

In vacancies for a programmer, I often see the following entry:

Ability to write complex SQL queries

Tell me, what are these complex queries?
For example, nested selects, or IN or INNER JOIN ?

I want to collect SQL queries for my portfolio :)

Answer 1

https://www.sql-ex.ru/ what is your rating? that's it...

Answer 2

Well, for example, when the interlocutor does not understand how the interlocutor's request works, but it works, the result is correct and faster than the interviewer did)
p / s / resume with a portfolio of requests - just a flop)

Answer 3

Go to the interview and you will be asked these very "difficult questions"