Drop cascade constraints Demo : Drop Cascade « Constraints « Oracle PL / SQL






Drop cascade constraints Demo


SQL> CREATE TABLE Employee(Employee_ID NUMBER(4) NOT NULL,
  2                   Employee_Name VARCHAR2(10),
  3                   JOB VARCHAR2(9),
  4                   Manager_ID NUMBER(4),
  5                   Start_Date DATE,
  6                   Salary NUMBER(7, 2),
  7                   COMM NUMBER(7, 2),
  8                   Deparment_ID NUMBER(2)
  9  );

Table created.

SQL>
SQL> INSERT INTO Employee VALUES (7369, 'SMITH',  'CLERK',     7902, TO_DATE('17-DEC-1980', 'DD-MON-YYYY'),  800, NULL, 20);

1 row created.

SQL> INSERT INTO Employee VALUES (7499, 'ALLEN',  'SALESMAN',  7698, TO_DATE('20-FEB-1981', 'DD-MON-YYYY'), 1600,  300, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7521, 'WARD',   'SALESMAN',  7698, TO_DATE('22-FEB-1981', 'DD-MON-YYYY'), 1250,  500, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7566, 'JONES',  'MANAGER',   7839, TO_DATE('2-APR-1981', 'DD-MON-YYYY'),  2975, NULL, 20);

1 row created.

SQL> INSERT INTO Employee VALUES (7654, 'MARTIN', 'SALESMAN',  7698, TO_DATE('28-SEP-1981', 'DD-MON-YYYY'), 1250, 1400, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7698, 'BLAKE',  'MANAGER',   7839, TO_DATE('1-MAY-1981', 'DD-MON-YYYY'),  2850, NULL, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7782, 'CLARK',  'MANAGER',   7839, TO_DATE('9-JUN-1981', 'DD-MON-YYYY'),  2450, NULL, 10);

1 row created.

SQL> INSERT INTO Employee VALUES (7788, 'SCOTT',  'ANALYST',   7566, TO_DATE('09-DEC-1982', 'DD-MON-YYYY'), 3000, NULL, 20);

1 row created.

SQL> INSERT INTO Employee VALUES (7839, 'KING',   'PRESIDENT', NULL, TO_DATE('17-NOV-1981', 'DD-MON-YYYY'), 5000, NULL, 10);

1 row created.

SQL> INSERT INTO Employee VALUES (7844, 'TURNER', 'SALESMAN',  7698, TO_DATE('8-SEP-1981', 'DD-MON-YYYY'),  1500,    0, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7876, 'ADAMS',  'CLERK',     7788, TO_DATE('12-JAN-1983', 'DD-MON-YYYY'), 1100, NULL, 20);

1 row created.

SQL> INSERT INTO Employee VALUES (7900, 'JAMES',  'CLERK',     7698, TO_DATE('3-DEC-1981', 'DD-MON-YYYY'),   950, NULL, 30);

1 row created.

SQL> INSERT INTO Employee VALUES (7902, 'FORD',   'ANALYST',   7566, TO_DATE('3-DEC-1981', 'DD-MON-YYYY'),  3000, NULL, 20);

1 row created.

SQL> INSERT INTO Employee VALUES (7934, 'MILLER', 'CLERK',     7782, TO_DATE('23-JAN-1982', 'DD-MON-YYYY'), 1300, NULL, 10);

1 row created.

SQL>
SQL> CREATE TABLE Department(Deparment_ID NUMBER(2),
  2                          Department_Name VARCHAR2(14),
  3                          Location VARCHAR2(13)
  4  );

Table created.

SQL>
SQL> INSERT INTO Department VALUES (10, 'ACCOUNTING', 'NEW YORK');

1 row created.

SQL> INSERT INTO Department VALUES (20, 'RESEARCH',   'DALLAS');

1 row created.

SQL> INSERT INTO Department VALUES (30, 'SALES',      'CHICAGO');

1 row created.

SQL> INSERT INTO Department VALUES (40, 'OPERATIONS', 'BOSTON');

1 row created.

SQL>
SQL> alter table Employee add constraint Employee_pk primary key(Employee_ID);

Table altered.

SQL> alter table Department add constraint Department_pk primary key(Deparment_ID);

Table altered.

SQL> alter table Employee add constraint Employee_fk_Department foreign key(Deparment_ID) references Department;

Table altered.

SQL> alter table Employee add constraint Employee_fk_Employee foreign key(Manager_ID) references Employee;

Table altered.

SQL>
SQL> select * from Employee;

EMPLOYEE_ID EMPLOYEE_N JOB       MANAGER_ID START_DAT     SALARY       COMM DEPARMENT_ID
----------- ---------- --------- ---------- --------- ---------- ---------- ------------
       7369 SMITH      CLERK           7902 17-DEC-80        800                      20
       7499 ALLEN      SALESMAN        7698 20-FEB-81       1600        300           30
       7521 WARD       SALESMAN        7698 22-FEB-81       1250        500           30
       7566 JONES      MANAGER         7839 02-APR-81       2975                      20
       7654 MARTIN     SALESMAN        7698 28-SEP-81       1250       1400           30
       7698 BLAKE      MANAGER         7839 01-MAY-81       2850                      30
       7782 CLARK      MANAGER         7839 09-JUN-81       2450                      10
       7788 SCOTT      ANALYST         7566 09-DEC-82       3000                      20
       7839 KING       PRESIDENT            17-NOV-81       5000                      10
       7844 TURNER     SALESMAN        7698 08-SEP-81       1500          0           30
       7876 ADAMS      CLERK           7788 12-JAN-83       1100                      20

EMPLOYEE_ID EMPLOYEE_N JOB       MANAGER_ID START_DAT     SALARY       COMM DEPARMENT_ID
----------- ---------- --------- ---------- --------- ---------- ---------- ------------
       7900 JAMES      CLERK           7698 03-DEC-81        950                      30
       7902 FORD       ANALYST         7566 03-DEC-81       3000                      20
       7934 MILLER     CLERK           7782 23-JAN-82       1300                      10

14 rows selected.

SQL> select * from Department;

DEPARMENT_ID DEPARTMENT_NAM LOCATION
------------ -------------- -------------
          10 ACCOUNTING     NEW YORK
          20 RESEARCH       DALLAS
          30 SALES          CHICAGO
          40 OPERATIONS     BOSTON

SQL>
SQL> drop table Department cascade constraints;

Table dropped.

SQL> drop table Employee cascade constraints;

Table dropped.

SQL>
SQL>

           
       








Related examples in the same category

1.Drop table with Foreign Key: cascade constraints