alter  session  set NLS_DATE_FORMAT = 'dd-mm-yyyy';
select sysdate from dual;

DROP  TABLE EMP       cascade constraints;
DROP  TABLE DEPT      cascade constraints;
DROP  TABLE SALGRADE  cascade constraints;
purge recyclebin;

CREATE TABLE DEPT (DEPTNO   NUMBER(2), DNAME    VARCHAR2(14), LOC      VARCHAR2(13) );
INSERT INTO  DEPT VALUES (10, 'ACCOUNTING', 'NEW YORK');
INSERT INTO  DEPT VALUES (20, 'RESEARCH',   'DALLAS'  );
INSERT INTO  DEPT VALUES (30, 'SALES',      'CHICAGO' );
INSERT INTO  DEPT VALUES (40, 'OPERATIONS', 'BOSTON'  );

CREATE TABLE EMP (EMPNO    NUMBER(4),ENAME VARCHAR2(10), JOB   VARCHAR2(9) , MGR    NUMBER(4)
                 ,HIREDATE DATE     ,SAL   NUMBER(7, 2), COMM  NUMBER(7, 2), DEPTNO NUMBER(2));
INSERT ALL
WHEN 1<2 THEN
INTO EMP VALUES ( 1, 'KING',   'PRESIDENT','', '17-11-1981', 5000,   '', 10)
INTO EMP VALUES ( 2, 'BLAKE',  'MANAGER',   1, '01-05-1981', 2850, NULL, 30)
INTO EMP VALUES ( 3, 'CLARK',  'MANAGER',   1, '09-06-1981', 2450, NULL, 10)
WHEN 1<2 THEN
INTO EMP VALUES ( 4, 'JONES',  'MANAGER',   1, '02-04-1981', 2975, NULL, 20)
INTO EMP VALUES ( 5, 'ALLEN',  'SALESMAN',  2, '20-02-1981', 1600,  300, 30)
INTO EMP VALUES ( 6, 'JAMES',  'CLERK',     2, '03-12-1981',  950, NULL, 30)
INTO EMP VALUES ( 7, 'MARTIN', 'SALESMAN',  2, '28-09-1981', 1250, 1400, 30)
INTO EMP VALUES ( 8, 'TURNER', 'SALESMAN',  2, '08-09-1981', 1500,    0, 30)
INTO EMP VALUES ( 9, 'WARD',   'SALESMAN',  2, '22-02-1981', 1250,  500, 30)
INTO EMP VALUES (10, 'MILLER', 'CLERK',     3, '23-01-1982', 1300, NULL, 10)
INTO EMP VALUES (11, 'FORD',   'ANALYST',   4, '03-12-1981', 3000, NULL, 20)
INTO EMP VALUES (12, 'SCOTT',  'ANALYST',   4, '09-12-1982', 3000, NULL, 20)
INTO EMP VALUES (13, 'SMITH',  'CLERK',    11, '17-11-1980',  800, NULL, 20)
INTO EMP VALUES (14, 'ADAMS',  'CLERK',    12, '12-01-1983', 1100, NULL, 20)
ELSE
INTO EMP VALUES (90, '90',     '90',       90, '28-09-1981', 90,   90,   90)
SELECT * FROM DUAL WHERE 1<2;

CREATE TABLE SALGRADE (GRADE   NUMBER, LOSAL   NUMBER, HISAL   NUMBER);
INSERT INTO SALGRADE select 1,  700, 1200 
FROM DUAL  UNION ALL select 2, 1201, 1400 
FROM DUAL  UNION ALL select 3, 1401, 2000 
FROM DUAL  UNION ALL select 4, 2001, 3000 
FROM DUAL  UNION ALL select 5, 3001, 9999 FROM DUAL;

COMMIT;
select * from tab;