4. Employee Database with Trigger

EXECUTION:

sql> select * from emp;

NAME ENO DEPTNO ADDR DOB S SALARY

------------- ---------- ------------- -------------------------------------------------- --------------- ---- ---------------

sathya 1000 5000 saibaba colony, coimbatore 15-SEP-74 f 10000

ramya 1002 5000 cluddalore main road, cluddalore 19-JAN-85 f 12000

rameshan 1003 5100 nsr road, coimbatore 30-JUL-56 m 10800

BEFORE TRIGGER EXECUTION:

sql> select * from works;

ENO PNO HOURS

---------- ---------- ----------

1000 p1 8

1002 p1 7

1003 p1 12

1000 p1 8

1002 p1 7

1003 p1 12

6 rows selected.

EXECUTION:

SQL> begin delete from emp where eno=&employee_number;

2 end;

3 /

Enter value for employee_number: 1002

old 1: begin delete from emp where eno=&employee_number;

new 1: begin delete from emp where eno=1002;

the employee and his

corresponding works are also deleted

PL/SQL procedure successfully completed.

AFTER TRIGGER EXECUTION:

SQL> SELECT * FROM WORKS;

ENO PNO HOURS

---------- ---------- ----------

1000 p1 8

1003 p1 12

1000 p1 8

1003 p1 12

SQL>SELECT * FROM EMP;

NAME ENO DEPTNO ADDR DOB S SALARY

------------- ---------- ------------- -------------------------------------------------- --------------- ---- ---------------

sathya 1000 5000 saibaba colony, coimbatore 15-SEP-74 f 10000

rameshan 1003 5100 nsr road, coimbatore 30-JUL-56 m 10800

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