Trigger execution

Question

I have asked in an interview i have 4 triggers(statement,rowwith before and after trigger).
Which triggers will execute in which Order?

Answer 1

Depends. For example, deleting from parent table where child table FK has ON DELETE CASCADE. In such case child table BEFORE statement trigger is executed for first child table delete statement only and child AFTER statement trigger is executed for last child table delete statement only:
CREATE TABLE PARENT(
                    ID NUMBER
ALTER TABLE PARENT
  ADD CONSTRAINT PARENT_PK
    PRIMARY KEY(
                ID
CREATE TRIGGER PARENT_BD_TRG
  BEFORE DELETE
  ON PARENT
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Parent before DELETE statement.'
END;
CREATE TRIGGER PARENT_BDR_TRG
  BEFORE DELETE
  ON PARENT
  FOR EACH ROW
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Parent before DELETE row.'
END;
CREATE TRIGGER PARENT_AD_TRG
  AFTER DELETE
  ON PARENT
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Parent after DELETE statement.'
END;
CREATE TRIGGER PARENT_ADR_TRG
  AFTER DELETE
  ON PARENT
  FOR EACH ROW
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Parent after DELETE row.'
END;
INSERT
  INTO PARENT
  SELECT  LEVEL
    FROM  DUAL
    CONNECT BY LEVEL <= 2
CREATE TABLE CHILD(
                    ID NUMBER
ALTER TABLE CHILD
  ADD CONSTRAINT CHILD_PARENT_FK
    FOREIGN KEY(
                ID
    REFERENCES PARENT(
                      ID
    ON DELETE CASCADE
CREATE TRIGGER CHILD_BD_TRG
  BEFORE DELETE
  ON CHILD
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Child before DELETE statement.'
END;
CREATE TRIGGER CHILD_BDR_TRG
  BEFORE DELETE
  ON CHILD
  FOR EACH ROW
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Child before DELETE row.'
END;
CREATE TRIGGER CHILD_ADR_TRG
  AFTER DELETE
  ON CHILD
  FOR EACH ROW
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Child after DELETE row.'
END;
CREATE TRIGGER CHILD_AD_TRG
  AFTER DELETE
  ON CHILD
  BEGIN
      DBMS_OUTPUT.PUT_LINE(
                           'Child after DELETE statement.'
END;
INSERT
  INTO CHILD
  SELECT  CEIL(LEVEL / 2)
    FROM  DUAL
    CONNECT BY LEVEL <= 4
COMMIT
SET SERVEROUTPUT ON
DELETE PARENT
Parent before DELETE statement.
Child before DELETE statement.
Parent before DELETE row.
Child before DELETE row.
Child after DELETE row.
Child before DELETE row.
Child after DELETE row.
Parent after DELETE row.
Parent before DELETE row.
Child before DELETE row.
Child after DELETE row.
Child before DELETE row.
Child after DELETE row.
Parent after DELETE row.
Child after DELETE statement.
Parent after DELETE statement.
2 rows deleted.
SQL>
SY.