SQL-Oracle：解决基本问题的难度，第2部分

Question

Problem: The HR department needs a query that prompts the user for an employee last name. The query then displays the last name and hire date of any employee in the same department as the employee whose name they supply(excluding that employee). For example, if the user enters Zlotkey, find all employees who work with Zlotkey (excluding Zlotkey).

I managed to do this so far, but i have no clue how to finish it. For now it shows me all employees after i write the last_name excluding it. Any suggestions please how to continue?

SELECT last_name, TO_CHAR(hire_date,'DD-MON-YYYY') AS "HIRE_DATE"
FROM   employees
WHERE  last_name <>ALL (SELECT '&last_name'
                         FROM  employees)

AND    department_id  IN  (SELECT department_id
                           ???....

PS: This problem is from the Oracle tutorials (Oracle Database 11g: SQL Fundamentals 1 of 1 (year 2009), Practice 7 , exercise 1 for people who already done this:).

Answer 1

Something like this?

SELECT last_name, TO_CHAR(hire_date,'DD-MON-YYYY') AS "HIRE_DATE"
FROM   employees a
JOIN (Select department_id from employees where last_name = :surname) b on a.department_id = b.department_id
and last_name <> :surname

EDIT The only problem with this type of solution is that if there are two people with the same surname in different departments, so it might be useful to maybe use something like an employee number as a filter instead of surname.

Answer 2

SELECT  LAST_NAME, HIRE_DATE 
FROM EMPLOYEES
WHERE DEPARTMENT_ID= (SELECT DEPARTMENT_ID 
FROM EMPLOYEES
WHERE LAST_NAME LIKE '&NAME')
AND LAST_NAME <> '&NAME';