Before Open / Close
Before open/close triggers are invoked immediately before an attempt is made to open or close a table (or a view of it).
A before open trigger is invoked when a table or a view is opened and or another view has not already opened the table.
This means that if your logic is "Open View 1", then "Open View 2" (where view 1 and view 2 are both based on the same table) then the trigger would be invoked when you open view 1, but not when you open view 2.
A before close trigger is invoked when a table or a view is closed and another view still does not have the table open.
This means that if your logic is "Close View 1", then "Close View 2" (where view 1 and view 2 are both based on the same table) then the trigger would be invoked when you close view 2, but not when you closed view 1.
After Open / Close
Is invoked identically to the "before" options but immediately after a successful attempt has been made to close the table.
Before Read
Is invoked immediately before an attempt is made to read a record from a table. Before input triggers have no access to "information" from the table (because the information has not been input yet) so their use should be considered carefully. Access to the key(s) being used to access the table is not possible in this mode so do not design triggers based on this premise.
After Read
Is invoked after a record has been successfully read from a table and just before the details of the record are passed back to the invoking function. Any virtual column logic has been completed by this stage.
Before Insert
Is invoked immediately before an attempt is made to insert a new record into a table. Please note the following:
After Insert
Is invoked immediately after a new record has been inserted into a table. Please note the following:
Before Update
Is invoked immediately before an attempt is made to update an existing record in a table. Please note the following:
After Update
Is invoked immediately after an existing record has been updated in a table. Please note the following:
Before Delete
Is invoked immediately before an attempt is made to delete an existing record from a table. Please note the following:
After Delete
Is invoked immediately after an existing record has been deleted from a table. Please note the following: