What is the difference between standalone and correlated subqueries?

Question

SQL Server

Hello, I tried to google different subqueries, but I didn’t really find anything about “autonomous” ones.
As I understand the following query

select e.FIO, e.Schet, s.Salary_data 
from Employee e, Salary s 
where e.Employee_ID = s.Employee_ID and s.Salary_data < 
(select Salary_data 
from Salary 
where Employee_ID = 1);

to tables


is correlated
, what does a standalone query look like, how is it built and what is the difference?

Answer 1

если подзапрос использует значения из другого запроса, то он Correlated subquery