Oracle PL/SQL/Constraints/Drop Cascade
Drop cascade constraints Demo
<source lang="sql">
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>
</source>
Drop table with Foreign Key: cascade constraints
<source lang="sql">
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>
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