Oracle PL/SQL Tutorial/SQL PLUS Session Environment/null

set null " [N/A]"

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> set null " [N/A]"
SQL>
SQL> select * from employees;
 EMPNO      last_name       INIT  JOB         MGR BDATE        MSAL DEPTNO
------ -------------------- ----- -------- ------ ---------- ------ ------
     1 Jason                N     TRAINER       2 18-12-1965    800     10
     2 Jerry                J     SALESREP      3 19-11-1966   1600     10
     3 Jord                 T     SALESREP      4 21-10-1967   1700     20
     4 Mary                 J     MANAGER       5 22-09-1968   1800     20
     5 Joe                  P     SALESREP      6 23-08-1969   1900     30
     6 Black                R     MANAGER       7 24-07-1970   2000     30
     7 Red                  A     MANAGER       8 25-06-1971   2100     40
 EMPNO      last_name       INIT  JOB         MGR BDATE        MSAL DEPTNO
------ -------------------- ----- -------- ------ ---------- ------ ------
     8 White                S     TRAINER       9 26-05-1972   2200     40
     9 Yellow               C     DIRECTOR     10 27-04-1973   2300     20
    10 Pink                 J     SALESREP  [N/A] 28-03-1974   2400     30
10 rows selected.
SQL>
SQL>
SQL> set null null
SQL>
SQL>
SQL> select * from employees;
 EMPNO      last_name       INIT  JOB         MGR BDATE        MSAL DEPTNO
------ -------------------- ----- -------- ------ ---------- ------ ------
     1 Jason                N     TRAINER       2 18-12-1965    800     10
     2 Jerry                J     SALESREP      3 19-11-1966   1600     10
     3 Jord                 T     SALESREP      4 21-10-1967   1700     20
     4 Mary                 J     MANAGER       5 22-09-1968   1800     20
     5 Joe                  P     SALESREP      6 23-08-1969   1900     30
     6 Black                R     MANAGER       7 24-07-1970   2000     30
     7 Red                  A     MANAGER       8 25-06-1971   2100     40
 EMPNO      last_name       INIT  JOB         MGR BDATE        MSAL DEPTNO
------ -------------------- ----- -------- ------ ---------- ------ ------
     8 White                S     TRAINER       9 26-05-1972   2200     40
     9 Yellow               C     DIRECTOR     10 27-04-1973   2300     20
    10 Pink                 J     SALESREP null   28-03-1974   2400     30
10 rows selected.
SQL>
SQL>
SQL> drop table employees;
Table dropped.
SQL>