Oracle PL/SQL Tutorial/Query Select/with

"With clause" and subquery

SQL>
SQL>
SQL> create table employees(
  2    empno      NUMBER(4)
  3  , ename      VARCHAR2(8)
  4  , init       VARCHAR2(5)
  5  , job        VARCHAR2(8)
  6  , mgr        NUMBER(4)
  7  , bdate      DATE
  8  , msal       NUMBER(6,2)
  9  , comm       NUMBER(6,2)
 10  , deptno     NUMBER(2) ) ;
Table created.
SQL>
SQL>
SQL> insert into employees values(1,"Jason",  "N",  "TRAINER", 2,   date "1965-12-18",  800 , NULL,  10);
1 row created.
SQL> insert into employees values(2,"Jerry",  "J",  "SALESREP",3,   date "1966-11-19",  1600, 300,   10);
1 row created.
SQL> insert into employees values(3,"Jord",   "T" , "SALESREP",4,   date "1967-10-21",  1700, 500,   20);
1 row created.
SQL> insert into employees values(4,"Mary",   "J",  "MANAGER", 5,   date "1968-09-22",  1800, NULL,  20);
1 row created.
SQL> insert into employees values(5,"Joe",    "P",  "SALESREP",6,   date "1969-08-23",  1900, 1400,  30);
1 row created.
SQL> insert into employees values(6,"Black",  "R",  "MANAGER", 7,   date "1970-07-24",  2000, NULL,  30);
1 row created.
SQL> insert into employees values(7,"Red",    "A",  "MANAGER", 8,   date "1971-06-25",  2100, NULL,  40);
1 row created.
SQL> insert into employees values(8,"White",  "S",  "TRAINER", 9,   date "1972-05-26",  2200, NULL,  40);
1 row created.
SQL> insert into employees values(9,"Yellow", "C",  "DIRECTOR",10,  date "1973-04-27",  2300, NULL,  20);
1 row created.
SQL> insert into employees values(10,"Pink",  "J",  "SALESREP",null,date "1974-03-28",  2400, 0,     30);
1 row created.
SQL>
SQL>
SQL>
SQL> with g as
  2        (select   x.deptno
  3         ,        avg(x.msal) avg_sal
  4         from     employees x
  5         group by x.deptno)
  6  select e.ename, e.init, e.msal
  7  from   employees e
  8         join      g
  9         using (deptno)
 10  where  e.msal > g.avg_sal;
     last_name       INIT    MSAL
-------------------- ----- ------
Pink                 J       2400
Yellow               C       2300
White                S       2200
Jerry                J       1600
4 rows selected.
SQL>
SQL> drop table employees;
Table dropped.
SQL>
SQL>

With statement and subquery

SQL>
SQL> create table emp
  2  ( empno      NUMBER(4)    constraint E_PK primary key
  3  , ename      VARCHAR2(8)
  4  , init       VARCHAR2(5)
  5  , job        VARCHAR2(8)
  6  , mgr        NUMBER(4)
  7  , bdate      DATE
  8  , sal       NUMBER(6,2)
  9  , comm       NUMBER(6,2)
 10  , deptno     NUMBER(2)    default 10
 11  ) ;
Table created.
SQL> insert into emp values(1,"Tom","N",   "TRAINER", 13,date "1965-12-17",  800 , NULL,  20);
1 row created.
SQL> insert into emp values(2,"Jack","JAM", "Tester",6,date "1961-02-20",  1600, 300,   30);
1 row created.
SQL> insert into emp values(3,"Wil","TF" ,  "Tester",6,date "1962-02-22",  1250, 500,   30);
1 row created.
SQL> insert into emp values(4,"Jane","JM",  "Designer", 9,date "1967-04-02",  2975, NULL,  20);
1 row created.
SQL> insert into emp values(5,"Mary","P",  "Tester",6,date "1956-09-28",  1250, 1400,  30);
1 row created.
SQL> insert into emp values(6,"Black","R",   "Designer", 9,date "1963-11-01",  2850, NULL,  30);
1 row created.
SQL> insert into emp values(7,"Chris","AB",  "Designer", 9,date "1965-06-09",  2450, NULL,  10);
1 row created.
SQL> insert into emp values(8,"Smart","SCJ", "TRAINER", 4,date "1959-11-26",  3000, NULL,  20);
1 row created.
SQL> insert into emp values(9,"Peter","CC",   "Designer",NULL,date "1952-11-17",  5000, NULL,  10);
1 row created.
SQL> insert into emp values(10,"Take","JJ", "Tester",6,date "1968-09-28",  1500, 0,     30);
1 row created.
SQL> insert into emp values(11,"Ana","AA",  "TRAINER", 8,date "1966-12-30",  1100, NULL,  20);
1 row created.
SQL> insert into emp values(12,"Jane","R",   "Manager",   6,date "1969-12-03",  800 , NULL,  30);
1 row created.
SQL> insert into emp values(13,"Fake","MG",   "TRAINER", 4,date "1959-02-13",  3000, NULL,  20);
1 row created.
SQL> insert into emp values(14,"Mike","TJA","Manager",   7,date "1962-01-23",  1300, NULL,  10);
1 row created.
SQL>
SQL> with g as
  2        (select   x.deptno
  3         ,        avg(x.sal) avg_sal
  4         from     emp x
  5         group by x.deptno)
  6  select e.ename, e.init, e.sal
  7  from   emp e
  8         join      g
  9         using (deptno)
 10  where  e.sal > g.avg_sal;
ENAME    INIT         SAL
-------- ----- ----------
Peter    CC          5000
Jane     JM          2975
Fake     MG          3000
Smart    SCJ         3000
Jack     JAM         1600
Black    R           2850
6 rows selected.
SQL>
SQL>
SQL> drop table emp;
Table dropped.
SQL>