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Using the tables below: Provide the SQL statements to: 12) For each employee, sh

ID: 3698592 • Letter: U

Question

Using the tables below:

Provide the SQL statements to:

12) For each employee, show how many employee(s) each supervises.

14) Retrieve the name of employee whose salary is greater than the average salary of his or her corresponding department.

19) List the name of each department, and the total number of employees with salaries greater than $30,000, and only the department with more than one employee.

20. List the name of department that has more than one employee who earns more than $30,000.

TABLE Employee

NAME                   SSN               BDATE             SEX            SALARY          SUPERSSN       DNO

-------------------           ---------            ---------               ---              ----------              ---------              --------

John B Smith         123456789       09-JAN-55        M               30000              333445555          5

Franklin T Wong      333445555      08-DEC-45       M               40000              888665555          5

Alicia J Zelaya        999887777       19-JUL-85        F                25000              987654321         4

Jennifer S Wallace    987654321     20-JUN-31       F                43000              888665555         4

Ramesh K Narayan    666884444    15-SEP-52       M              38000              333445555         5

Joyce A English         453453453    31-JUL-62        F               25000              333445555         5

Ahmad V Jabbar        987987987    29-MAR-59       M              25000              987654321         4

James E Borg            888665555 10-NOV-27          M              55000                                       1

TABLE Department;

DNAME                        DNUMBER         MGRSSN              MGRSTARTD

---------------                       --------                   ---------                     ---------

Research                             5                              333445555           22-MAY-78

Administration                    4                              987654321           01-JAN-85

Headquarters                      1                              888665555           19-JUN-71

TABLE Project

PNAME                      PNUMBER          PLOCATION                       DNUM

---------------                       --------                 ---------------                       --------

ProductX                             1                         Bellaire                          5

ProductY                             2                         Sugarland                      5

ProductZ                              3                        Houston                         5

Computerization                   10                       Stafford                          4

Reorganization                     20                       Houston                          1

Newbenefits                        30                        Stafford                            4

TABLE Deptlocation

DNUMBER         DLOCATION

--------                   ---------------

1                              Houston

4                              Stafford

5                              Bellaire

5                              Houston

5                              Sugarland

TABLE workson

ESSN                 PNO                     HOURS

---------                --------                    ----------

123456789           1                              32.5

123456789           2                              7.5

666884444           3                              40

453453453           1                              20

453453453           2                              20

333445555           2                              10

333445555           3                              10

333445555           10                           10

333445555           20                           10

999887777           30                           30

999887777           10                           10

ESSN                      PNO            HOURS

---------                      --------            ----------

987987987          10                        35

987987987          30                         5

987654321          30                        20

987654321          20                        15

888665555          20

Explanation / Answer

12) Aggregate function COUNT() is used along with group by to get the employee count under each supervisor.


SELECT SUPERSSN, COUNT(SSN)
FROM Employee
GROUP BY SUPERSSN;

14) Subquery is used in WHERE clause to check salary of employee greater than the average salary of their department.


SELECT SSN, NAME,
FROM Employee e
WHERE SALARY > (SELECT AVG(SALARY) FROM Employee em WHERE em.DNO = e.DNO);

19) 2 tables namely Department, Employee and joined. Aggreagte function COUNT() is used along with group by clause to get the number of employees in each department. Where clause is used to filter the result with salary greater than 30,000.


SELECT DNAME, DNUMBER, COUNT(SSN)
FROM Department d
INNER JOIN Employee e
ON e.DNO = d.DNUMBER
WHERE e.SALARY > 30,000
GROUP BY DNAME, DNUMBER
HAVING COUNT(SSN) > 1;

20)
SELECT DNAME, COUNT(SSN)
FROM Department d
INNER JOIN Employee e
ON e.DNO = d.DNUMBER
WHERE e.SALARY > 30,000
GROUP BY DNAME
HAVING COUNT(SSN) > 1;