Oracle PL/SQL Tutorial/Table Joins/Group
Adding Ordering to the Query Containing the GROUP BY
The ORDER BY is applied last.
SQL>
SQL> -- create demo table
SQL> create table Employee(
2 EMPNO NUMBER(3),
3 ENAME VARCHAR2(15 BYTE),
4 HIREDATE DATE,
5 ORIG_SALARY NUMBER(6),
6 CURR_SALARY NUMBER(6),
7 REGION VARCHAR2(1 BYTE)
8 )
9 /
Table created.
SQL>
SQL> create table job (
2 EMPNO NUMBER(3),
3 jobtitle VARCHAR2(20 BYTE)
4 )
5 /
Table created.
SQL>
SQL> insert into job (EMPNO, Jobtitle) values (1,"Tester");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (2,"Accountant");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (3,"Developer");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (4,"COder");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (5,"Director");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (6,"Mediator");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (7,"Proffessor");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (8,"Programmer");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (9,"Developer");
1 row created.
SQL>
SQL>
SQL> -- prepare data
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (1, "Jason", to_date("19960725","YYYYMMDD"), 1234, 8767, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (2, "John", to_date("19970715","YYYYMMDD"), 2341, 3456, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (3, "Joe", to_date("19860125","YYYYMMDD"), 4321, 5654, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (4, "Tom", to_date("20060913","YYYYMMDD"), 2413, 6787, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (5, "Jane", to_date("20050417","YYYYMMDD"), 7654, 4345, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (6, "James", to_date("20040718","YYYYMMDD"), 5679, 6546, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (7, "Jodd", to_date("20030720","YYYYMMDD"), 5438, 7658, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (8, "Joke", to_date("20020101","YYYYMMDD"), 8765, 4543, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (9, "Jack", to_date("20010829","YYYYMMDD"), 7896, 1232, "E")
3 /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
2 /
EMPNO ENAME HIREDATE ORIG_SALARY CURR_SALARY R
---------- --------------- --------- ----------- ----------- -
1 Jason 25-JUL-96 1234 8767 E
2 John 15-JUL-97 2341 3456 W
3 Joe 25-JAN-86 4321 5654 E
4 Tom 13-SEP-06 2413 6787 W
5 Jane 17-APR-05 7654 4345 E
6 James 18-JUL-04 5679 6546 W
7 Jodd 20-JUL-03 5438 7658 E
8 Joke 01-JAN-02 8765 4543 W
9 Jack 29-AUG-01 7896 1232 E
9 rows selected.
SQL> select * from job
2 /
EMPNO JOBTITLE
---------- --------------------
1 Tester
2 Accountant
3 Developer
4 COder
5 Director
6 Mediator
7 Proffessor
8 Programmer
9 Developer
9 rows selected.
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 AND e.empno = j.empno
5 GROUP BY j.jobtitle ORDER BY maxsalary
6 /
JOBTITLE COUNT(*) MAXSALARY MINSALARY
-------------------- ---------- ---------- ----------
Tester 1 1234 1234
Accountant 1 2341 2341
COder 1 2413 2413
Proffessor 1 5438 5438
Mediator 1 5679 5679
Director 1 7654 7654
Developer 2 7896 4321
Programmer 1 8765 8765
8 rows selected.
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL> drop table job
2 /
Table dropped.
The Order with GROUP BY
SQL>
SQL>
SQL>
SQL>
SQL> -- create demo table
SQL> create table Employee(
2 EMPNO NUMBER(3),
3 ENAME VARCHAR2(15 BYTE),
4 HIREDATE DATE,
5 ORIG_SALARY NUMBER(6),
6 CURR_SALARY NUMBER(6),
7 REGION VARCHAR2(1 BYTE)
8 )
9 /
Table created.
SQL>
SQL> create table job (
2 EMPNO NUMBER(3),
3 jobtitle VARCHAR2(20 BYTE)
4 )
5 /
Table created.
SQL>
SQL> insert into job (EMPNO, Jobtitle) values (1,"Tester");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (2,"Accountant");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (3,"Developer");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (4,"COder");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (5,"Director");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (6,"Mediator");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (7,"Proffessor");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (8,"Programmer");
1 row created.
SQL> insert into job (EMPNO, Jobtitle) values (9,"Developer");
1 row created.
SQL>
SQL>
SQL> -- prepare data
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (1, "Jason", to_date("19960725","YYYYMMDD"), 1234, 8767, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (2, "John", to_date("19970715","YYYYMMDD"), 2341, 3456, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (3, "Joe", to_date("19860125","YYYYMMDD"), 4321, 5654, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (4, "Tom", to_date("20060913","YYYYMMDD"), 2413, 6787, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (5, "Jane", to_date("20050417","YYYYMMDD"), 7654, 4345, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (6, "James", to_date("20040718","YYYYMMDD"), 5679, 6546, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (7, "Jodd", to_date("20030720","YYYYMMDD"), 5438, 7658, "E")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (8, "Joke", to_date("20020101","YYYYMMDD"), 8765, 4543, "W")
3 /
1 row created.
SQL> insert into Employee(EMPNO, EName, HIREDATE, ORIG_SALARY, CURR_SALARY, REGION)
2 values (9, "Jack", to_date("20010829","YYYYMMDD"), 7896, 1232, "E")
3 /
1 row created.
SQL>
SQL>
SQL>
SQL> -- display data in the table
SQL> select * from Employee
2 /
EMPNO ENAME HIREDATE ORIG_SALARY CURR_SALARY R
---------- --------------- --------- ----------- ----------- -
1 Jason 25-JUL-96 1234 8767 E
2 John 15-JUL-97 2341 3456 W
3 Joe 25-JAN-86 4321 5654 E
4 Tom 13-SEP-06 2413 6787 W
5 Jane 17-APR-05 7654 4345 E
6 James 18-JUL-04 5679 6546 W
7 Jodd 20-JUL-03 5438 7658 E
8 Joke 01-JAN-02 8765 4543 W
9 Jack 29-AUG-01 7896 1232 E
9 rows selected.
SQL> select * from job
2 /
EMPNO JOBTITLE
---------- --------------------
1 Tester
2 Accountant
3 Developer
4 COder
5 Director
6 Mediator
7 Proffessor
8 Programmer
9 Developer
9 rows selected.
SQL>
SQL>
SQL> SELECT j.jobtitle, COUNT(*), MAX(orig_salary) maxsalary, MIN(orig_salary) minsalary
2 FROM employee e, job j
3 WHERE e.orig_salary < 43000 AND e.empno = j.empno
4 GROUP BY j.jobtitle
5 /
JOBTITLE COUNT(*) MAXSALARY MINSALARY
-------------------- ---------- ---------- ----------
Proffessor 1 5438 5438
Programmer 1 8765 8765
Tester 1 1234 1234
COder 1 2413 2413
Accountant 1 2341 2341
Developer 2 7896 4321
Director 1 7654 7654
Mediator 1 5679 5679
8 rows selected.
SQL>
SQL> -- clean the table
SQL> drop table Employee
2 /
Table dropped.
SQL> drop table job
2 /
Table dropped.