Example: Correlated subquery in select-list

Department names and numbers are found in the CORPDATA.DEPARTMENT table. However, DEPARTMENT only has the manager's number, not the manager's name. To find the name of the manager for each department, you need to find the employee number from the EMPLOYEE table that matches the manager number in the DEPARTMENT table and return the name for the row that matches. Only departments that currently have a manager assigned are to be returned. Execute the following:

SELECT DEPTNO, DEPTNAME, 
    (SELECT FIRSTNME CONCAT ' ' CONCAT 
         MIDINIT CONCAT ' ' CONCAT LASTNAME
       FROM EMPLOYEE X
       WHERE X.EMPNO = Y.MGRNO) AS MANAGER_NAME
   FROM DEPARTMENT Y
   WHERE MGRNO IS NOT NULL

For each row returned for DEPTNO and DEPTNAME, the system finds where EMPNO = MGRNO and returns the manager's name. The result table produced by the query has the following values: