1. 2
Types of Subqueries

2. Two types of Subqueries
In a noncorrelated subquery, values are passed from the inner query to the outer query.
proc sql;
select Job_Title, avg(Salary) as MeanSalary
from orion.Staff
group by Job_Title
having avg(Salary) >
(select avg(Salary) as MeanSalary
from orion.Staff) ;
quit;
Stand-alone query

3. Correlated Subsqueries

4. Subqueries
In a correlated subquery, the outer query must provide information to the subquery before it can be successfully resolved.
proc sql;
select Employee_ID, avg(Salary) as MeanSalary
from orion.Employee_Addresses
where 'AU'=
(select Country
from Work.Supervisors
where Employee_Addresses.Employee_ID=
Supervisors.Employee_ID) ;
quit;
Requires Information from
the outer query