Re: Create a Trigger for an existing View

On 10 Apr., 06:45, "Vladimir M. Zakharychev"
<vladimir.zakharyc...@xxxxxxxxx> wrote:
On Apr 10, 2:43 am, "Dean Tomasevic" <dean.tomase...@xxxxxxxxxxxxxx>
wrote:



Hi!

I created a view from the two existing tables (DEMO_USERS and
DEMO_ORDERS).

Code:
CREATE VIEW DEMO_MY_TEST AS
SELECT DEMO_USERS.USER_ID, DEMO_ORDERS.ORDER_ID
FROM DEMO_USERS
INNER JOIN DEMO_ORDERS
ON DEMO_ORDERS.USER_ID = DEMO_USERS.USER_ID

So now my job is to update my view if anybody will take an new order.
As example:
If user X with the USER_ID 2 will complete a new order my trigger must
updating the view.

But i have problems with the trigger, i know that i must write an
updating trigger, but the actuator for the trigger is an "insert into"
into the DEMO_ORDERS table, because only if a new order will insert
into the DEMO_ORDERS table, then the trigger must be activated and
updating the view.

Thanks a lot.

Dean Tomasevic

I may be reading it wrong, but there's no need to update the view - it
will pick up changes from the underlying tables automatically. A view
is just a stored query, it doesn't immediately materialize and store
the result set until "updated"; every time you query the view, the
view statement will be re-executed against current data. So when
someone adds an order, its ORDER_ID will be returned when you SELECT *
FROM DEMO_MY_TEST without any extra coding effort.

Hth,
Vladimir M. Zakharychev
N-Networks, makers of Dynamic PSP(tm)
http://www.dynamicpsp.com


hi.

You're right, the view will auto updating if i klick on the view.
but what is if i create a new table, and insert the result of
"CREATE VIEW DEMO_MY_TEST AS
SELECT DEMO_USERS.USER_ID, DEMO_ORDERS.ORDER_ID
FROM DEMO_USERS
INNER JOIN DEMO_ORDERS
ON DEMO_ORDERS.USER_ID = DEMO_USERS.USER_ID"
into my new table.
Then i need a trigger which auto statrts if the DEMO_ORDERS table has
a new entry, because then
I must insert the new entry of DEMO_ORDERS over a trigger into my new
table.

i hope you understand what i mean ;)

Thanks
Dean T.

.

Relevant Pages

  • Re: Create a Trigger for an existing View
    ... INNER JOIN DEMO_ORDERS ... If user X with the USER_ID 2 will complete a new order my trigger must ... updating trigger, but the actuator for the trigger is an "insert into" ... I must insert the new entry of DEMO_ORDERS over a trigger into my new ...
    (comp.databases.oracle.server)
  • Re: Create a Trigger for an existing View
    ... INNER JOIN DEMO_ORDERS ... If user X with the USER_ID 2 will complete a new order my trigger must ... updating trigger, but the actuator for the trigger is an "insert into" ... I must insert the new entry of DEMO_ORDERS over a trigger into my new ...
    (comp.databases.oracle.server)
  • Re: Create a Trigger for an existing View
    ... INNER JOIN DEMO_ORDERS ... If user X with the USER_ID 2 will complete a new order my trigger must ... updating trigger, but the actuator for the trigger is an "insert into" ... is just a stored query, it doesn't immediately materialize and store ...
    (comp.databases.oracle.server)
  • Re: Create a Trigger for an existing View
    ... INNER JOIN DEMO_ORDERS ... If user X with the USER_ID 2 will complete a new order my trigger must ... updating trigger, but the actuator for the trigger is an "insert into" ... I must insert the new entry of DEMO_ORDERS over a trigger into my new ...
    (comp.databases.oracle.server)
  • Re: Create a Trigger for an existing View
    ... INNER JOIN DEMO_ORDERS ... If user X with the USER_ID 2 will complete a new order my trigger must ... I must insert the new entry of DEMO_ORDERS over a trigger into my new ... and when a transaction starts. ...
    (comp.databases.oracle.server)