Oracle Triggers Precedence

Trigger Firing sequence:
Order as follows

First Logon Triggers are fired

1.PRE-LOGON
2.ON-LOGON
3.POST-LOGON

After that Pre Triggers

4. PRE-FORM
5. PRE-BLOCK
6. PRE-TEXT

After that WHEN-NEW Triggers

7. WHEN-NEW-FORM-INSTANCE
8. WHEN-NEW-BLOCK-INSTANCE
9. WHEN-NEW-ITEM-INSTANCE

After that ITEM Level Triggers

After this focus is on the first item of the Block. If you type some data and press the tab key following trigger will fire in sequence


10.KEY-NEXT-ITEM (This trigger is present on the item level).


11.POST-CHANGE (This trigger is present on the item level).


12.WHEN-VALIDATE-ITEM (This trigger is present on the item level).

13.POST-TEXT-ITEM (This trigger is present on the item level).


14.WHEN-NEW-ITEM-INSTANCE (Block Level Trigger).

Now focus will go the next item present on the form.
If there are no further items present on the screen them if we enter data and press tab key then only KEY-NEXT-ITEM is fired. Now suppose we close the form then the item level triggers are fired.

POST TRIGGERS 

15.POST-BLOCK
16.POST-FORM

Now the form will be closed.