i want to print the employee details on department wise with group above report with the fields DEPTNO------group above ENAME ------ SAL-------- COMM------ I WANT OUTPUT LIKE THIS ---------------------------------------------------------- 1)FIRST DEPTNO=10 EMPLOYEES DISPLAYED IN FIRST PAGE AND DEPTNO=20 EMPLOYEES DISPLAYED IN 2ND PAGE WHAT I HAVE TO DO OUTPUT ------- --FIRST_PAGE ----------- DEPTNO:10 ENAME SAL COMM KING 5000 A 2000 2222 ---- =- -- SECONDPAGE DEPTNO:20 ENAME SAL COMM MILLER 220 22 D 45 23 -- - - LIKE THE ABOVE PROCDURE REPORTS HOW MANY DEPARTMENTS ARE EXISITING IN EMP TABLE

plz explain when we are using pre-query,post-query,pre-insert and post-insert?plz explain with one example