Oracle PL/SQL Programming: A Developer's Workbook

Intermediate

16-22.	What happens when the following trigger executes? CREATE OR REPLACE TRIGGER employee_ins_t1 BEFORE UPDATE ON employee FOR EACH ROW DECLARE cur PLS_INTEGER := DBMS_SQL.open_cursor; fdbk PLS_INTEGER; stmt VARCHAR2(2000); BEGIN stmt := 'BEGIN IF :old.' || emp_pkg.col_name || '= ' || emp_pkg.col_value || '''' || ' THEN :new.salary := :new.salary * 2; ' || ' END IF;' || ' END; '; DBMS_SQL.parse (cur, sql_stmt, DBMS_SQL.native); fdbk := DBMS_SQL.execute (cur); END;
16-23.	Provide a template for a trigger that raises an error when a client application violates a business rule (e.g., a trigger that raises an error if a user attempts to delete a row from the employee table).
16-24.	You want to issue DML statements or execute PL/SQL stored programs inside a trigger. Which of the following describes how you must grant the necessary privileges on the underlying object? Privileges on the underlying object must be granted through the database roles. Privileges on the underlying object must be granted directly to the user who owns the object. Privileges can be granted either through database roles or directly from the user who owns the object.
16-25.	Indicate whether the following triggers are valid or invalid (a valid procedure both compiles and executes without error): CREATE OR REPLACE TRIGGER emp_audit_trg BEFORE INSERT OR UPDATE ON employee FOR EACH ROW BEGIN IF (inserting) THEN INSERT INTO employee_audit VALUES (:new.empno, USER, 'Inserting a row into table_a'); ELSE INSERT INTO ...