These triggers demonstrate the use of the :new correlation identifier.
SQL>
SQL> CREATE TABLE lecturer (
2 id NUMBER(5) PRIMARY KEY,
3 first_name VARCHAR2(20),
4 last_name VARCHAR2(20),
5 major VARCHAR2(30),
6 current_credits NUMBER(3)
7 );
Table created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10001, 'Scott', 'Lawson','Computer Science', 11);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major, current_credits)
2 VALUES (10002, 'Mar', 'Wells','History', 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10003, 'Jone', 'Bliss','Computer Science', 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10004, 'Man', 'Kyte','Economics', 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10005, 'Pat', 'Poll','History', 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10006, 'Tim', 'Viper','History', 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10007, 'Barbara', 'Blues','Economics', 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10008, 'David', 'Large','Music', 4);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10009, 'Chris', 'Elegant','Nutrition', 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10010, 'Rose', 'Bond','Music', 7);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10011, 'Rita', 'Johnson','Nutrition', 8);
1 row created.
SQL>
SQL> INSERT INTO lecturer (id, first_name, last_name, major,current_credits)
2 VALUES (10012, 'Sharon', 'Clear','Computer Science', 3);
1 row created.
SQL>
SQL>
SQL> CREATE OR REPLACE TRIGGER GenerateStudentID
2 BEFORE INSERT OR UPDATE ON lecturer
3 FOR EACH ROW
4 BEGIN
5 SELECT 20001
6 INTO :new.ID
7 FROM dual;
8 END GenerateStudentID;
9 /
Trigger created.
SQL>
SQL> INSERT INTO lecturer (first_name, last_name)
2 VALUES ('L', 'L');
1 row created.
SQL>
SQL>
SQL>
SQL> select * from lecturer;
ID FIRST_NAME LAST_NAME
---------- -------------------- --------------------
MAJOR CURRENT_CREDITS
------------------------------ ---------------
10001 Scott Lawson
Computer Science 11
10002 Mar Wells
History 4
10003 Jone Bliss
Computer Science 8
ID FIRST_NAME LAST_NAME
---------- -------------------- --------------------
MAJOR CURRENT_CREDITS
------------------------------ ---------------
10004 Man Kyte
Economics 8
10005 Pat Poll
History 4
10006 Tim Viper
History 4
ID FIRST_NAME LAST_NAME
---------- -------------------- --------------------
MAJOR CURRENT_CREDITS
------------------------------ ---------------
10007 Barbara Blues
Economics 7
10008 David Large
Music 4
10009 Chris Elegant
Nutrition 8
ID FIRST_NAME LAST_NAME
---------- -------------------- --------------------
MAJOR CURRENT_CREDITS
------------------------------ ---------------
10010 Rose Bond
Music 7
10011 Rita Johnson
Nutrition 8
10012 Sharon Clear
Computer Science 3
ID FIRST_NAME LAST_NAME
---------- -------------------- --------------------
MAJOR CURRENT_CREDITS
------------------------------ ---------------
20001 L L
13 rows selected.
SQL>
SQL> drop table lecturer;
Table dropped.
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