Retrieving Data from Multiple Tables Eng. Mohammed Alokshiya

Islamic University of Gaza Faculty of Engineering Computer Engineering Dept. Database Lab (ECOM 4113)

Lab 5 Exercises Solutions

Retrieving Data from Multiple Tables

Eng. Mohammed Alokshiya

November 11, 2014

Exercises Solutions: 1. Write a query (without using set operators) to retrieve name

and id for all countries that have no departments located in them. Suggested Solution SELECT COUNTRY_NAME FROM COUNTRIES WHERE COUNTRY_ID NOT IN ( SELECT COUNTRY_ID FROM DEPARTMENTS JOIN LOCATIONS USING (LOCATION_ID) JOIN COUNTRIES USING (COUNTRY_ID) ) ORDER BY 1;

2. Write a query to retrieve all employees whose salary is more

than the salary of any employee from department 60. Suggested Solution SELECT FIRST_NAME, LAST_NAME, SALARY FROM EMPLOYEES WHERE SALARY > ANY ( SELECT SALARY FROM EMPLOYEES WHERE DEPARTMENT_ID = 60 );

3. Write a query to retrieve first name, last name, and department

name, for employees whose salary is more than all their collagenous’ salaries in the same department. Suggested Solution SELECT FIRST_NAME, LAST_NAME, SALARY, DEPARTMENT_NAME FROM EMPLOYEES E LEFT OUTER JOIN DEPARTMENTS D ON E.DEPARTMENT_ID = D.DEPARTMENT_ID WHERE SALARY >= ALL ( SELECT SALARY FROM EMPLOYEES EE WHERE E.DEPARTMENT_ID = EE.DEPARTMENT_ID ) ORDER BY 3 DESC;

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4. Write a query to retrieve employees whose job has minimum

salary 4200 and maximum salary 9000. Suggested Solution SELECT FIRST_NAME, LAST_NAME, SALARY FROM EMPLOYEES JOIN JOBS USING(JOB_ID) WHERE MIN_SALARY = 4200 AND MAX_SALARY = 9000;

5. Write a query to retrieve departments’ names and cities for all

departments that has more than 5 employees. Suggested Solution SELECT DEPARTMENT_NAME, CITY FROM DEPARTMENTS D JOIN LOCATIONS USING (LOCATION_ID) WHERE (SELECT COUNT(*) FROM EMPLOYEES E WHERE D.DEPARTMENT_ID = E.DEPARTMENT_ID) > 5;

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