Oracle PL/SQL Tutorial/Trigger/Trigger and Transaction

Autonomous triggers

SQL>
SQL>
SQL> CREATE TABLE order_tab(
  2     order_id     NUMBER(10) PRIMARY KEY,
  3     order_date   DATE NOT NULL,
  4     total_qty    NUMBER,
  5     total_price  NUMBER(15,2),
  6     supp_id      NUMBER(6)
  7  );
Table created.
SQL>
SQL> CREATE TABLE order_tran_coming_in(
  2     order_id              NUMBER(10)  NOT NULL,
  3     order_date            DATE        NOT NULL,
  4     tran_coming_in_date   DATE        NOT NULL,
  5     success_flag          VARCHAR2(1) DEFAULT "N" NOT NULL);
Table created.
SQL>
SQL>
SQL>
SQL> create or replace trigger bi_order_tab
  2  before insert on order_tab for each row
  3  declare
  4    pragma autonomous_transaction;
  5  begin
  6    insert into order_tran_coming_in values (:NEW.order_id,
  7                                             :NEW.order_date,
  8                                             SYSDATE,
  9                                             "N");
 10    commit;
 11  end;
 12  /
Trigger created.
SQL> create or replace trigger ai_order_tab
  2  after insert on order_tab for each row
  3  declare
  4    pragma autonomous_transaction;
  5  begin
  6    update order_tran_coming_in
  7    set    success_flag = "Y"
  8    where  order_id = :NEW.order_id;
  9    commit;
 10  end;
 11  /
Trigger created.
SQL> BEGIN
  2    INSERT INTO order_tab VALUES(102,SYSDATE,NULL,NULL,1001);
  3    INSERT INTO order_tab VALUES(103,SYSDATE,NULL,NULL,1001);
  4    INSERT INTO order_tab VALUES(103,SYSDATE,NULL,NULL,1001);
  5  EXCEPTION WHEN DUP_VAL_ON_INDEX THEN
  6    ROLLBACK;
  7  END;
  8  /
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> drop table order_tran_coming_in;
Table dropped.
SQL>
SQL> drop table order_tab;
Table dropped.
SQL>

Call PRAGMA AUTONOMOUS_TRANSACTION procedure

SQL>
SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
  2                    ENAME VARCHAR2(10),
  3                    JOB VARCHAR2(9),
  4                    MGR NUMBER(4),
  5                    HIREDATE DATE,
  6                    SAL NUMBER(7, 2),
  7                    COMM NUMBER(7, 2),
  8                    DEPTNO NUMBER(2));
Table created.
SQL>
SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK",    7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7521, "WARD",  "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER",  7839, TO_DATE("2-APR-1981",  "DD-MON-YYYY"), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL> CREATE OR REPLACE PROCEDURE update_salary (dept_in IN NUMBER)
  2  IS
  3     PRAGMA AUTONOMOUS_TRANSACTION;
  4
  5     CURSOR myemps IS
  6        SELECT empno FROM emp
  7         WHERE deptno = dept_in
  8           FOR UPDATE NOWAIT;
  9
 10  BEGIN
 11     FOR rec IN myemps
 12     LOOP
 13        UPDATE emp SET sal = sal * 2 WHERE empno = rec.empno;
 14     END LOOP;
 15     COMMIT;
 16  END;
 17  /
Procedure created.
SQL>
SQL> BEGIN
  2     UPDATE emp SET sal = sal * 2;
  3     update_salary (10);
  4  END;
  5  /
BEGIN
*
ERROR at line 1:
ORA-00054: resource busy and acquire with NOWAIT specified
ORA-06512: at "sqle.UPDATE_SALARY", line 6
ORA-06512: at "sqle.UPDATE_SALARY", line 11
ORA-06512: at line 3

SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL>

Commit in trigger

SQL>
SQL> CREATE TABLE employee_compensation (
  2     company VARCHAR2(100),
  3     NAME VARCHAR2(100),
  4     compensation NUMBER);
Table created.
SQL>
SQL> CREATE TABLE employee_history (
  2     NAME VARCHAR2(100),
  3     description VARCHAR2(255),
  4     occurred_on DATE);
Table created.
SQL>
SQL> CREATE OR REPLACE TRIGGER bef_ins_ceo_comp
  2     BEFORE INSERT
  3     ON employee_compensation
  4     FOR EACH ROW
  5  DECLARE
  6     PRAGMA AUTONOMOUS_TRANSACTION;
  7  BEGIN
  8     INSERT INTO employee_history
  9          VALUES (:NEW.NAME, "BEFORE INSERT", SYSDATE);
 10
 11     COMMIT;
 12  END;
 13  /
Trigger created.
SQL> CREATE OR REPLACE TRIGGER aft_ins_ceo_comp
  2     AFTER INSERT
  3     ON employee_compensation
  4     FOR EACH ROW
  5  DECLARE
  6     PRAGMA AUTONOMOUS_TRANSACTION;
  7  BEGIN
  8     IF :NEW.rupensation > 1000000000
  9     THEN
 10        RAISE VALUE_ERROR;
 11     ELSE
 12        INSERT INTO employee_history VALUES (:NEW.NAME, "AFTER INSERT", SYSDATE);
 13        COMMIT;
 14     END IF;
 15  EXCEPTION
 16     WHEN OTHERS
 17     THEN
 18        ROLLBACK;
 19        RAISE;
 20  END;
 21  /
Trigger created.
SQL> COLUMN name FORMAT a20
SQL> COLUMN description FORMAT a30
SQL>
SQL> SELECT NAME, description
  2       , TO_CHAR (occurred_on, "MM/DD/YYYY HH:MI:SS") occurred_on
  3    FROM employee_history;
no rows selected
SQL>
SQL> BEGIN
  2     INSERT INTO employee_compensation VALUES ("B", "J", 9100000);
  3
  4     INSERT INTO employee_compensation VALUES ("B", "A", 10700000);
  5
  6     INSERT INTO employee_compensation VALUES ("B", "Sally Bigdeal", 1000000001);
  7
  8  END;
  9  /
BEGIN
*
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error
ORA-06512: at "sqle.AFT_INS_CEO_COMP", line 15
ORA-04088: error during execution of trigger "sqle.AFT_INS_CEO_COMP"
ORA-06512: at line 6

SQL>
SQL> SELECT   NAME, description
  2         , TO_CHAR (occurred_on, "MM/DD/YYYY HH:MI:SS") occurred_on
  3      FROM employee_history
  4  ORDER BY occurred_on;
NAME                 DESCRIPTION                    OCCURRED_ON
-------------------- ------------------------------ -------------------
J                    BEFORE INSERT                  07/24/2008 08:03:16
J                    AFTER INSERT                   07/24/2008 08:03:16
Sally Bigdeal        BEFORE INSERT                  07/24/2008 08:03:16
A                    AFTER INSERT                   07/24/2008 08:03:16
A                    BEFORE INSERT                  07/24/2008 08:03:16
SQL>
SQL>
SQL> DROP TABLE employee_compensation;
Table dropped.
SQL>
SQL> DROP TABLE employee_history;
Table dropped.
SQL>

Mark trigger with PRAGMA AUTONOMOUS_TRANSACTION

SQL>
SQL> CREATE TABLE employee_compensation (
  2     company VARCHAR2(100),
  3     name VARCHAR2(100),
  4     compensation NUMBER,
  5     layoffs NUMBER);
Table created.
SQL>
SQL>
SQL> CREATE TABLE employee_history (
  2     name VARCHAR2(100),
  3     description VARCHAR2(255),
  4     occurred_on DATE);
Table created.
SQL>
SQL>
SQL> CREATE OR REPLACE PROCEDURE employee_audit (
  2     name IN VARCHAR2,
  3     description IN VARCHAR2,
  4     occurred_on IN DATE
  5     )
  6  IS
  7     PRAGMA AUTONOMOUS_TRANSACTION;
  8  BEGIN
  9     INSERT INTO employee_history VALUES (
 10        employee_audit.name,
 11        employee_audit.description,
 12        employee_audit.occurred_on
 13        );
 14
 15     IF employee_audit.description LIKE "AFTER%"
 16     THEN
 17        RAISE VALUE_ERROR;
 18     END IF;
 19
 20     COMMIT;
 21  END;
 22  /
Procedure created.
SQL> CREATE OR REPLACE TRIGGER bef_ins_ceo_comp
  2  BEFORE INSERT ON employee_compensation FOR EACH ROW
  3  DECLARE
  4     ok BOOLEAN := TRUE;
  5  BEGIN
  6     employee_audit (
  7        :new.name, "BEFORE INSERT", SYSDATE);
  8  END;
  9  /
Trigger created.
SQL>
SQL> CREATE OR REPLACE TRIGGER aft_ins_ceo_comp
  2  AFTER INSERT ON employee_compensation FOR EACH ROW
  3  DECLARE
  4     ok BOOLEAN := FALSE;
  5  BEGIN
  6     employee_audit (
  7        :new.name, "AFTER INSERT", SYSDATE);
  8  END;
  9  /
Trigger created.
SQL>
SQL> COLUMN name FORMAT a20
SQL> COLUMN description FORMAT a30
SQL>
SQL> SELECT name,
  2         description,
  3         TO_CHAR (occurred_on, "MM/DD/YYYY HH:MI:SS") occurred_on
  4    FROM employee_history;
no rows selected
SQL>
SQL> BEGIN
  2     INSERT INTO employee_compensation VALUES ("M", "J", 9100000, 2700);
  3
  4     INSERT INTO employee_compensation VALUES ("A", "H", 33200000, 3300);
  5
  6     INSERT INTO employee_compensation VALUES ("E", "G", 10700000, 20100);
  7
  8     ROLLBACK; -- I wish!
  9  END;
 10  /
BEGIN
*
ERROR at line 1:
ORA-06502: PL/SQL: numeric or value error
ORA-06512: at "sqle.EMPLOYEE_AUDIT", line 17
ORA-06512: at "sqle.AFT_INS_CEO_COMP", line 4
ORA-04088: error during execution of trigger "sqle.AFT_INS_CEO_COMP"
ORA-06512: at line 2

SQL>
SQL> SELECT name,
  2         description,
  3         TO_CHAR (occurred_on, "MM/DD/YYYY HH:MI:SS") occurred_on
  4    FROM employee_history;
NAME                 DESCRIPTION                    OCCURRED_ON
-------------------- ------------------------------ -------------------
J                    BEFORE INSERT                  07/24/2008 08:03:13
SQL>
SQL>
SQL>
SQL>
SQL> DROP TABLE employee_history;
Table dropped.
SQL>
SQL> DROP TABLE employee_compensation;
Table dropped.
SQL>

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE

SQL>
SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
  2                    ENAME VARCHAR2(10),
  3                    JOB VARCHAR2(9),
  4                    MGR NUMBER(4),
  5                    HIREDATE DATE,
  6                    SAL NUMBER(7, 2),
  7                    COMM NUMBER(7, 2),
  8                    DEPTNO NUMBER(2));
Table created.
SQL>
SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK",    7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7521, "WARD",  "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER",  7839, TO_DATE("2-APR-1981",  "DD-MON-YYYY"), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL>
SQL>
SQL> CREATE OR REPLACE PROCEDURE fire_em_all
  2  IS
  3     PRAGMA AUTONOMOUS_TRANSACTION;
  4  BEGIN
  5     DELETE FROM emp;
  6
  7     COMMIT;
  8  EXCEPTION
  9     WHEN OTHERS
 10     THEN
 11        ROLLBACK;
 12  END;
 13  /
Procedure created.
SQL>
SQL> show errors
No errors.
SQL>
SQL> DECLARE
  2     num   INTEGER;
  3  BEGIN
  4     SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
  5
  6     SELECT COUNT (*)
  7       INTO num
  8       FROM emp;
  9
 10     DBMS_OUTPUT.put_line ("Before isolated AT delete " || num);
 11     fire_em_all;
 12
 13     SELECT COUNT (*)
 14       INTO num
 15       FROM emp;
 16
 17     DBMS_OUTPUT.put_line ("After isolated AT delete " || num);
 18     COMMIT; -- ROLLBACK;
 19
 20     SELECT COUNT (*)
 21       INTO num
 22       FROM emp;
 23
 24     DBMS_OUTPUT.put_line ("After MT commit " || num);
 25  END;
 26  /
PL/SQL procedure successfully completed.
SQL>
SQL>
SQL> drop table emp;
Table dropped.
SQL>
SQL>

Transaction with "pragma autonomous_transaction"

SQL>
SQL> CREATE TABLE EMP (EMPNO NUMBER(4) NOT NULL,
  2                    ENAME VARCHAR2(10),
  3                    JOB VARCHAR2(9),
  4                    MGR NUMBER(4),
  5                    HIREDATE DATE,
  6                    SAL NUMBER(7, 2),
  7                    COMM NUMBER(7, 2),
  8                    DEPTNO NUMBER(2));
Table created.
SQL>
SQL>
SQL> INSERT INTO EMP VALUES (7369, "SMITH", "CLERK",    7902, TO_DATE("17-DEC-1980", "DD-MON-YYYY"), 800, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7499, "ALLEN", "SALESMAN", 7698, TO_DATE("20-FEB-1981", "DD-MON-YYYY"), 1600, 300, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7521, "WARD",  "SALESMAN", 7698, TO_DATE("22-FEB-1981", "DD-MON-YYYY"), 1250, 500, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7566, "JONES", "MANAGER",  7839, TO_DATE("2-APR-1981",  "DD-MON-YYYY"), 2975, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7654, "MARTIN", "SALESMAN", 7698,TO_DATE("28-SEP-1981", "DD-MON-YYYY"), 1250, 1400, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7698, "BLAKE", "MANAGER", 7839,TO_DATE("1-MAY-1981", "DD-MON-YYYY"), 2850, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7782, "CLARK", "MANAGER", 7839,TO_DATE("9-JUN-1981", "DD-MON-YYYY"), 2450, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7788, "SCOTT", "ANALYST", 7566,TO_DATE("09-DEC-1982", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7839, "KING", "PRESIDENT", NULL,TO_DATE("17-NOV-1981", "DD-MON-YYYY"), 5000, NULL, 10);
1 row created.
SQL> INSERT INTO EMP VALUES (7844, "TURNER", "SALESMAN", 7698,TO_DATE("8-SEP-1981", "DD-MON-YYYY"), 1500, 0, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7876, "ADAMS", "CLERK", 7788,TO_DATE("12-JAN-1983", "DD-MON-YYYY"), 1100, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7900, "JAMES", "CLERK", 7698,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 950, NULL, 30);
1 row created.
SQL> INSERT INTO EMP VALUES (7902, "FORD", "ANALYST", 7566,TO_DATE("3-DEC-1981", "DD-MON-YYYY"), 3000, NULL, 20);
1 row created.
SQL> INSERT INTO EMP VALUES (7934, "MILLER", "CLERK", 7782,TO_DATE("23-JAN-1982", "DD-MON-YYYY"), 1300, NULL, 10);
1 row created.
SQL>
SQL> create or replace procedure child
  2  as
  3          pragma autonomous_transaction;
  4          l_ename emp.ename%type;
  5  begin
  6
  7      update emp set ename = "y" where ename = "BLAKE";
  8      rollback to Parent_Savepoint;
  9      commit;
 10  end;
 11  /
Procedure created.
SQL>
SQL> create or replace procedure parent
  2  as
  3          l_ename emp.ename%type;
  4  begin
  5      savepoint Parent_Savepoint;
  6      update emp set ename = "x" where ename = "KING";
  7
  8      child;
  9      rollback;
 10  end;
 11  /
Procedure created.
SQL>
SQL> exec parent
BEGIN parent; END;
*
ERROR at line 1:
ORA-01086: savepoint "PARENT_SAVEPOINT" never established
ORA-06512: at "sqle.CHILD", line 8
ORA-06512: at "sqle.PARENT", line 8
ORA-06512: at line 1

SQL>
SQL>
SQL> drop table emp;
Table dropped.
SQL>