Table Joins Oracle PLSQL

SQL>
SQL> -- create demo table
SQL> create table Employee(
  2    empno              Number(3)  NOT NULL, -- Employee ID
  3    ename              VARCHAR2(10 BYTE),   -- Employee Name
  4    hireDate          DATE,                -- Date Employee Hired
  5    orig_salary        Number(8,2),         -- Orignal Salary
  6    curr_salary        Number(8,2),         -- Current Salary
  7    region             VARCHAR2(1 BYTE)     -- Region where employeed
  8  )
  9  /
Table created.
SQL>
SQL> create table job(
  2    empno              Number(3)  NOT NULL, -- Employee ID
  3    jobtitle           VARCHAR2(10 BYTE)    -- Employee job title
  4  )
  5  /
Table created.
SQL> -- prepare data for employee table
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(122,'Alison',to_date('19960321','YYYYMMDD'), 45000,       48000,       'E')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(123, 'James',to_date('19781212','YYYYMMDD'), 23000,       32000,       'W')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(104,'Celia',to_date('19821024','YYYYMMDD'), 53000,       58000,        'E')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(105,'Robert',to_date('19840115','YYYYMMDD'), 31000,      36000,        'W')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(116,'Linda', to_date('19870730','YYYYMMDD'), 43000,       53000,       'E')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(117,'David', to_date('19901231','YYYYMMDD'), 78000,       85000,       'W')
  3  /
1 row created.
SQL> insert into Employee(empno,  ename,  hireDate,                       orig_salary, curr_salary, region)
  2                values(108,'Jode',  to_date('19960917','YYYYMMDD'), 21000,       29000,       'E')
  3  /
1 row created.
SQL>
SQL> -- prepare data for job table
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(101,   'Painter');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(122,   'Tester');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(123,   'Dediator');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(104,   'Chemist');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(105,   'Accountant');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(116,   'Manager');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(117,   'Programmer');
1 row created.
SQL>
SQL> insert into job(empno, jobtitle)
  2           values(108,   'Developer');
1 row created.
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
  2  /
Hit a key to continue
     EMPNO ENAME      HIREDATE  ORIG_SALARY CURR_SALARY R
---------- ---------- --------- ----------- ----------- -
       122 Alison     21-MAR-96       45000       48000 E
       123 James      12-DEC-78       23000       32000 W
       104 Celia      24-OCT-82       53000       58000 E
       105 Robert     15-JAN-84       31000       36000 W
       116 Linda      30-JUL-87       43000       53000 E
       117 David      31-DEC-90       78000       85000 W
       108 Jode       17-SEP-96       21000       29000 E
7 rows selected.
SQL> select * from job;
Hit a key to continue
     EMPNO JOBTITLE
---------- ----------
       101 Painter
       122 Tester
       123 Dediator
       104 Chemist
       105 Accountant
       116 Manager
       117 Programmer
       108 Developer
8 rows selected.
SQL> -- Adding Ordering to the Query Containing the GROUP BY
SQL>
SQL>
SQL> SELECT j.jobtitle, COUNT(*), MAX(orig_salary) maxsalary,
  2    MIN(orig_salary) minsalary
  3  FROM employee e, job j
  4  WHERE e.orig_salary < 43000
  5    AND e.empno = j.empno
  6  GROUP BY j.jobtitle
  7  ORDER BY maxsalary;
Hit a key to continue
JOBTITLE     COUNT(*)  MAXSALARY  MINSALARY
---------- ---------- ---------- ----------
Developer           1      21000      21000
Dediator            1      23000      23000
Accountant          1      31000      31000
SQL>
SQL>
SQL> drop table job;
Table dropped.
SQL>
SQL> -- clean the table
SQL> drop table Employee;
Table dropped.
SQL>
SQL>