Triggers on Views

I'm looking for thoughts and opinions about triggers on views...
My project involves loading 3 nested objects on a queue for each of 4 databases. The three objects hold field data from 11 source tables. To minimize the number of Update triggers I was pondering the possibility of building a single flat View for each database that returns all fields for the 3 objects.
Thanks in advance...

I do not think you can create a trigger on a view.Actually, you can:
http://www.oracle.com/pls/db111/search?word=instead+of&partno=
http://www.oracle.com/pls/db102/search?word=instead+of&partno=

Similar Messages

Application specific button on FPM toolbar to call action triggered in view

Hello,
In the content area of my FPM is an ALV with some buttons, e.g. clicking one of the button opens up certain ALV column for editing (for simplicity, I omit the details besides simply enable the columns).
With FPM, I want the button to be placed in the toolbar as a application specific button. How do I achieve the same functionality e.g. from PROCESS_EVENT method calling an action (to open up certain ALV column for editing) via the application specific button placed on the toolbar communicating with the action/method found in the view controller ? Thank you.
Regards
Kir Chern

Hi Arvind,
I tried as follows :
- Create an event in the component controller, say 'MA'
- Within PROCESS_EVENT, raise the event as follows :
data : lo_fpm type ref to if_fpm,
         lo_event type ref to cl_fpm_event.
create object lo_event
     exporting
        iv_event_id = 'MA'.
   lo_fpm = cl_fpm_factory=>get_instance( ).
   lo_fpm->raise_event( io_event = lo_event ).
- In the view controller, create an event handler which subscribe to the event, MA of the component controller.
However, the code in the event handler is never executed despite the event being raised. Not sure how FPM event flow works here.
Can anyone advise ? Thank you.
Regards
Kir Chern

Triggering and view XML messages in SAP AMI

We have configured the AMI. Also setup the AMI enabled devices.
We have created Meter Reading Orders for the periodic meter reading as bulk .
But the creation of MROs does not trigger creation of XML messages.
We found the Enterprise Service responsible for meter reading order Request Smart Meter Meter Reading Document Creation as Bulk SmartMeterMeterReadingDocumentERPBulkCreateRequest_Out
But the XML messages are not getting generated on MRO creation. Also no XML message generated on AMI enabled device creation. Would like to know where we can view the generated XML and also trouble shoot.
Thanks in advance for the information
Vijay

Hi,
Thanks a lot for the informaiton , I could go into SXMB_MONI with date and time stamp to view the XML message, still i am not able to view it.
Is there any thing specific needs to be configured to have the XML message in SXMB_MONI
The process we are following is we are creating periodic meter reads and using the transaction ELMU Customized to our needs to trigger the SmartMeterMeterReadingDocumentERPBulkCreateRequest_Out . Are we following the right approach.
Can you provide the check points.
thanks,
Vijay
Edited by: vijay gunti on May 26, 2010 8:39 AM
Edited by: vijay gunti on May 26, 2010 8:46 AM
Edited by: vijay gunti on May 26, 2010 8:49 AM

View on DB Table

I want to create a view on DB Table eg CSKS. Can anyone show me how to do this or Show me where I can find information to create view on DB Table.
Thanks.

hi anil,
In database theory, a view is a virtual or logical table composed of the result set of a query. Unlike ordinary tables (base tables) in a relational database, a view is not part of the physical schema: it is a dynamic, virtual table computed or collated from data in the database. Changing the data in a table alters the data shown in the view.
The result of a view is stored in a permanent table whereas the result of a query is displayed in a temporary table.
Views can provide advantages over tables;
They can subset the data contained in a table
They can join and simplify multiple tables into a single virtual table
Views can act as aggregated tables, where aggregated data (sum, average etc.) are calculated and presented as part of the data
Views can hide the complexity of data, for example a view could appear as Sales2000 or Sales2001, transparently partitioning the actual underlying table
Views take very little space to store; only the definition is stored, not a copy of all the data they present
Depending on the SQL engine used, views can provide extra security.
Views can limit the exposure to which a table or tables are exposed to the outer world
Just like functions (in programming) provide abstraction, views can be used to create abstraction. Also, just like functions, views can be nested, thus one view can aggregate data from other views. Without the use of views it would be much harder to normalise databases above second normal form. Views can make it easier to create lossless join decomposition.
Rows available through a view are not sorted. A view is a relational table, and the relational model states that a table is a set of rows. Since sets are not sorted - per definition - the rows in a view are not ordered either. Therefore, an ORDER BY clause in the view definition is meaningless and the SQL standard (SQL:2003) does not allow this for the subselect in a CREATE VIEW statement.
Read-only vs. updatable views
Views can be read-only or updatable. If the database system is able to determine the reverse mapping from the view schema to the schema of the underlying base tables, then the view is updatable. INSERT, UPDATE, and DELETE operations can be performed on updatable views. Read-only views do not support such operations because the DBMS is not able to map the changes to the underlying base tables.
Some systems support the definition of INSTEAD OF triggers on views. This technique allows the definition of logic that shall be executed instead of an insert, update, or delete operation on the views. Thus, data modifications on read-only views can be implemented. However, an INSTEAD OF trigger does not change the read-only or updatable property of the view itself.
Advanced view features
Various database management systems have extended the views from read-only subsets of data. The Oracle database introduced the concept of materialized views, which are pre-executed, non-virtual views commonly used in data warehousing. They are a static snapshot of the data and may include data from remote sources. The accuracy of a materialized view depends on the frequency or trigger mechanisms behind its updates. DB2 provides so-called materialized query tables (MQTs) for the same purpose. Microsoft SQL Server, introduced in the 2000 version, indexed views which only store a separate index from the table, but not the entire data.
Equivalency:
A view is equivalent to its source query. When queries are run against views, the query is modified. For example, if there exists a view named Accounts_view and the content is:
accounts view:
SELECT name,
       money_received,
       money_sent,
       (money_received - money_sent) AS balance,
       address,
FROM table_customers c
JOIN accounts_table a
    ON a.customerid = c.customer_id
The application would simply run a simple query such as:
Sample query
SELECT name,
       balance
FROM accounts_view
The RDBMS then takes the simple query, replaces the equivalent view, then sends the following to the optimiser:
Preprocessed query:
SELECT name,
       balance
FROM (SELECT name,
               money_received,
               money_sent,
               (money_received - money_sent) AS balance,
               address,
          FROM table_customers c JOIN accounts_table a
               ON a.customerid = c.customer_id        )
From this point on the optimizer takes the query, removes unnecessary complexity (i.e. it is not necessary to read the address, since the parent invocation does not make use of it) and then sends the query to the SQL engine for processing.
thanks
karthik
reawrd me if usefull

Instead of trigger on view error

I've created a view, a form on that view and an INSTEAD OF update trigger on that view. When I press the update button in the form I get
Error: An unexpected error occurred: ORA-22816: unsupported feature with RETURNING clause (WWV-16016)
The error changes if I remove the trigger, but I need the trigger because the view is not updateable. I've recreated the problem with a simple view on the emp table.
Here's the emp view and trigger.
create or replace view vw_emp
as select *
from emp;
create or replace trigger vw_emp_burow
instead of update on vw_emp
referencing new as new old as old
for each row
begin
null;
end;In the emp case, the update proceeds fine once I drop the trigger.
Is this a bug or have I done something wrong? Has anyone else tried this?
(Portal 3.0.6.6.5 on 8.1.7 on Solaris)
Responses appreciated.

I was on the beta program, and ran into this problem with the beta version, and the EA version. Oracle told me that because of the underlying architecture of Oracle Portal, this was not easy to fix, so it would not be fixed in any 3.0 release.
I am hoping they fix it in the 3.1 release, though that will not be out until something like next August.
This is really an annoying bug, because using INSTEAD OF triggers on views would be a great way to make views that work well with Oracle Portal, while keeping the database normalized!
Ken Atkins
Computer Resource Team (www.crtinc.com)
Check out my Oracle Tip site at:
http://www.arrowsent.com/oratip
null

DM 3.0.0.665 instead of triggers not generating DDL correctly

There seems to be a bug in the DDL generation for manually created INSTEAD OF triggers on views. The INSTEAD OF trigger does not have the INSTEAD OF clause upon DDL generation. Instead, it has the BEFORE clause. It seems to be treating INSTEAD OF triggers as normal triggers. Note: When I reversed engineered a database that already had an INSTEAD OF trigger, it imported and generated DDL was fine. This bug shows itself when manually creating INSTEAD OF triggers.
Steps to replicate:
1. In any design that has a view.
2. In the physical model, find the view, expand it, right click to create Trigger for view
3. By definition, a trigger on a view can only be an instead of trigger.
4. The dialog box will have the 'Triggering time' showing as INSTEAD OF. You can't change it. (Which there is no reason to do anyway)
5. Generate DDL. When generating the DDL, the trigger will not be generated as INSTEAD OF, it will be generated as a BEFORE (INSERT/UPDATE/DELETE).
Included DDL generation from a simple database (I did not modify the DDL generated):
-- Generated by Oracle SQL Developer Data Modeler 3.0.0.665
-- at: 2011-03-30 13:16:32 EDT
-- site: Oracle Database 10g
-- type: Oracle Database 10g
-- CREATE DATABASE DB2
-- CONTROLFILE REUSE
-- MAXLOGFILES 1
-- MAXLOGMEMBERS 1
-- MAXLOGHISTORY 0
-- MAXDATAFILES 10
-- MAXINSTANCES 1
-- ARCHIVELOG
-- FORCE LOGGING
-- DATAFILE
-- '' SIZE 0 K REUSE
CREATE TABLE TABLE_1
Column_1 VARCHAR2 (1)
) LOGGING
CREATE OR REPLACE VIEW VIEW_1 ( Column_1 )
AS SELECT
TABLE_1.Column_1
FROM
TABLE_1 TABLE_1 ;
CREATE OR REPLACE TRIGGER Trg1
BEFORE INSERT ON VIEW_1
FOR EACH ROW
BEGIN
NULL;
END;
-- Oracle SQL Developer Data Modeler Summary Report:
-- CREATE TABLE 1
-- CREATE INDEX 0
-- ALTER TABLE 0
-- CREATE VIEW 1
-- CREATE PACKAGE 0
-- CREATE PACKAGE BODY 0
-- CREATE PROCEDURE 0
-- CREATE FUNCTION 0
-- CREATE TRIGGER 1
-- CREATE STRUCTURED TYPE 0
-- CREATE COLLECTION TYPE 0
-- CREATE CLUSTER 0
-- CREATE CONTEXT 0
-- CREATE DATABASE 1
-- CREATE DIMENSION 0
-- CREATE DIRECTORY 0
-- CREATE DISK GROUP 0
-- CREATE ROLE 0
-- CREATE ROLLBACK SEGMENT 0
-- CREATE SEQUENCE 0
-- CREATE MATERIALIZED VIEW 0
-- CREATE SYNONYM 0
-- CREATE TABLESPACE 0
-- CREATE USER 0
-- DROP TABLESPACE 0
-- DROP DATABASE 0
-- ERRORS 0
-- WARNINGS 0

Hi,
Thanks for reporting this problem. I logged a bug on it.
David

Trigger of a view

Good morning,
Does a trigger of a view start like a trigger of a table ?
I mean, a view searches its data in a table of a linked DB. If a row is added in the table, will the trigger of the view run ?
Thank you very much.
Patrick

If a row is added in the table, will the trigger of the view run ?Triggers on views are INSTEAD OF and are specified for views as objects - NOT the tables you include in your selection in views. Because of this only DML applied to views (not tables) fire "instead of" triggers:
SQL> create table t (id number);
Table created.
SQL> create view t_v as select * from t;
View created.
SQL> create trigger tab_t
2 before insert on t
3 begin
4 dbms_output.put_line('Table trigger');
5 end;
6 /
Trigger created.
SQL> create trigger view_tr
2 instead of insert on t_v
3 begin
4 dbms_output.put_line('View trigger');
5 end;
6 /
Trigger created.
SQL> insert into t values(1);
Table trigger
1 row created.
SQL> insert into t_v values(2);
View trigger
1 row created.Rgds.

Calling functions on module view

Greetings!
I have five modules within a viewstack. In one of these
modules is a datagrid which I'd like to update via HTTP service
each time the user views the module via switching the viewstack.
I've tried placing a creationComplete attribute in the module
tag to call the httpservice, but this calls the service when the
parent is loaded, and I only want it called when the module is
viewed.
I've also tried a show attribute in the module tag, but that
doesn't fire at all.
Would appreciate suggestions. TIA!

>> update via HTTP service each time the user views the
module via switching the viewstack.
If you break down your case, you will see the answer.
What triggers the viewing of your module in the viewstack?
The selectedIndex change in the Viewstack. So if you were to
connect this change with the desired action I think it should
work.

Reminders won't stay in date view

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Any thoughts?

My wife and I have the same problem. Our temporary solution is to Turn Wi-Fi Off (assuming you're on a computer that only connects to the internet over Wi-Fi) while making any significant changes to the Reminders.
It appears as though we're constantly being interupted (date window and name field closing) because it's trying to sync in the middle of typing and my wife types fast and she can't beat it.
This is definantly an Apple problem that needs to be resolved.

Changed Data Capture (CDC) when view as a Source

Hello All,
We implemented Changed Data Capture (CDC) by taking table as a source and we used to JKM Oracle Simple KM and it is working fine. But, we need to implement CDC by taking View as a source. Included Primary key at ODI Level for this view as CDC requires this on the source.
As we cannot create triggers on views and also while creating journal view prefixed with JV${table_name}, getting the following errror:
"1446 : 72000 : java.sql.SQLException: ORA-01446: cannot select ROWID from view with DISTINCT, GROUP BY, etc."
How can we achieve CDC if our source is a view?
Any suggestions..
Thanks,
-Vency

Hi,
Its not issue of a "lock" so no luck..
Its definitely the issue with the view..
I also got the real error as:
ORA-012024:Cannot select FOR UPDATE from view with DISTINCT,GROUP by etc..
Wonder why this is the error, as my view does not have DISTINCT,GROUP By etc..
Also checked
select * from USER_UPDATABLE_COLUMNS ;
and found that none of the columns are updateable..
So how to make these updateable and get my form work?

Coupling between component controller and view controller

Hello,
I have seen some discussions in this forum regarding the possibilities of calling / triggering a view controllers's method from a component controller's method; obviously the Web Dynpro framework only provides for the other direction (view ctrl -> comp ctrl) via handle <i>wd_comp_controller</i>.
Some people proposed raising events in the comp controller and catching these in the view controller, others pointed out that any dependance of a view controller on a component controller would violate MVC principles.
Now, I can't see why a tighter coupling (in both ways) between controllers within one component would harm MVC in any way. So I suggest to "register" a view controller in the pertaining component controller if necessary:
this_controller = wd_this->wd_get_api( ).
wd_comp_controller->register_view_ctrl_XYZ( this_controller ).
This way the component controller can save the reference and later call any method on it. What do you think, does anything argue against this practice?
Regards,
Sebastian

Hi Sebastian,
I wouldn't try to explain whether it is violating the MVC principles or not.
Can you please explain how to call methods of view using the view controller?
have you tried using an example???
I want to give a small example which I think is a basic disadvantage of calling View methods from component controller.
Suppose I have 30 methods in a view and such 7 views in a component (I think this is a very common example).
Till now one is very clear that if I have a method in view, it will be called at maximum by other methods with in the view. That means at any point of time, my search is limited to 30 methods.
Now if component controller can also call my search will become horrible and spread to 210 methods, unless otherwise, you are very good at naming attributes and wont make the mistake of assigning attributes wrongly.
Imagine the effort if the outside components also access these methods through interface.
Also I dont think that the webdynpro phase model can support this way of calling view methods. You might be successful once, but then you are trying to open a can of worms.
This is my way of thinking...
Also, it would be great if you can tell me whether you are successful in calling views methods or not???
Thanks,
Anand

Using a dump how can i create a ER diagram

Can any one tell me how can i draw a ER diagram automaticaly by using an existing Database.i mean i have a database with all the relationship,triggers and views now i want to make a ER diagram automaticaly by using this database ... is there any tool for this or is oracle provides any tool can any one help me out to solve this problem
thx in advance....

As you are asking on the Designer forum,I am assuming you have a Designer Repository set up. If this is the case,you can use Designer to capture the design of your schema and create a schema model. You can create an ERD from this schema model by using Designer's table to entity retrofit utility. Check out the Designer demos on this site for more. (http://www.oracle.com/technology/products/designer/demos.htm)
If you do not have a Designer Repository setup, why not try JDeveloper? You can download the latest JDeveloper 10g Preview release from OTN and, using the connection node, connect to the required schema and pull the tables from your schema onto a Database diagram. JDeveloper allows you to quickly and easily review your schema model visually.
You can also create UML Class models based on your schema.
There are numerous demos on the JDeveloper area for the UML modeling JDeveloper offers. (http://www.oracle.com/technology/products/jdev/index.html)
Regards
Sue Harper

Cannot drop table

Versions are Oracle 11.2.0.1.0 and SQL Developer 4.0.0.12 on Windows 7 Ultimate SP1.
Hi
I'm following the CBT Nuggets SQL Fundementals training (video #11) and cannot drop a table I have just created. The command executed and error are:
drop table newprods;
Error starting at line : 1 in command -
drop table newprods
Error report -
SQL Error: ORA-00604: error occurred at recursive SQL level 1
ORA-20000: Cannot drop object
ORA-06512: at line 2
00604. 00000 - "error occurred at recursive SQL level %s"
*Cause:    An error occurred while processing a recursive SQL statement
           (a statement applying to internal dictionary tables).
*Action:   If the situation described in the next error on the stack
           can be corrected, do so; otherwise contact Oracle Support.
As the HR user I created two tables and created a FK constraint between them. After truncating the table with this FK, I am unable to drop it. Even if I remove the FK, the error is the same. Issing the command in SQL*Plus gives the same error.
This is the first time I have created any tables since installing Oracle on this machine and is my first attempt at dropping a table. I have not created any sequences, triggers or views based on these newly created tables.
Does anyone have any ideas?
Cheers

C:\Oracle>sqlplus hr@orcl
SQL*Plus: Release 11.2.0.1.0 Production on Wed Sep 4 18:58:55 2013
Copyright (c) 1982, 2010, Oracle. All rights reserved.
Enter password:
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> CREATE TABLE table1 (column1 VARCHAR2(20 BYTE));
Table created.
SQL> select * from table1;
no rows selected
SQL> drop table table1;
drop table table1
ERROR at line 1:
ORA-00604: error occurred at recursive SQL level 1
ORA-20000: Cannot drop object
ORA-06512: at line 2
SQL>
Can I run a query to see if there are any triggeres on the table?
EDIT: Ok it looks like no triggers:
SQL> show user
USER is "SYS"
SQL> select * from DBA_TRIGGERS where table_name like '%table1%';
no rows selected
SQL> select * from USER_TRIGGERS where table_name like '%table1%';
no rows selected

Help needed in Identifying dependent objects

Hi all,
Basically I need to identify the object related to Integration which is not there in one of our software product under development as compare to other(existing) already developed so that we can apply them in the product being developed.
I need to find these below from few of the packages given to me
     dependent packages/functions to read and update data
1)     Tables
2)     Packages
3)     Triggers
4)     Views
5) Jobs
I would request you to help me in carrying out this faster, I have plsql Developer tool, how to start with so that i m not mess up with and complete it faster.
Regards,
Asif.

Thankx Pierre Forstmann.
Dear All,
Can any one help me in identifying all dependent objects for one object.
Will this works for me I found from the above link provided,
as for the time being I do not have the dba priviliges...
If I am able to get the dba prviliges will this code works for me to get the
required information....
Regards,
AAK.
SQL>
create or replace type myScalarType as object
( lvl number,
rname varchar2(30),
rowner varchar2(30),
rtype varchar2(30)
Type created.
SQL> create or replace type myTableType as table of
myScalarType
Type created.
SQL>
SQL> create or replace
function depends( p_name in varchar2,
p_type in varchar2,
p_owner in varchar2 default USER,
p_lvl in number default 1 ) return myTableType
AUTHID CURRENT_USER
as
l_data myTableType := myTableType();
procedure recurse( p_name in varchar2,
p_type in varchar2,
p_owner in varchar2,
p_lvl in number )
is
begin
if ( l_data.count > 1000 )
then
raise_application_error( -20001, 'probable connect by loop,
aborting' );
end if;
for x in ( select /*+ first_rows */ referenced_name,
referenced_owner,
referenced_type
from dba_dependencies
where owner = p_owner
and type = p_type
and name = p_name )
loop
l_data.extend;
l_data(l_data.count) :=
myScalarType( p_lvl, x.referenced_name,
x.referenced_owner, x.referenced_type );
recurse( x.referenced_name, x.referenced_type,
x.referenced_owner, p_lvl+1);
end loop;
end;
begin
l_data.extend;
l_data(l_data.count) := myScalarType( 1, p_name, p_owner, p_type );
recurse( p_name, p_type, p_owner, 2 );
return l_data;
end;
Function created.
SQL>
SQL> set timing on
SQL>
SQL> select * from table(
cast(depends('DBA_VIEWS','VIEW','SYS') as myTableType ) );
---select * from table(cast('USER_VIEWS') as myTableType ) );
LVL     RNAME          ROWNER          RTYPE
1     DBA_VIEWS     SYS               VIEW
2     TYPED_VIEW$ SYS               TABLE
2     USER$          SYS               TABLE
2     VIEW$          SYS               TABLE
2     OBJ$          SYS               TABLE
2     SUPEROBJ$ SYS               TABLE
2     STANDARD SYS               PACKAGE
7 rows selected.
Elapsed: 00:00:00.42
SQL>
SQL>
SQL> drop table t;
Table dropped.
Elapsed: 00:00:00.13
SQL> create table t ( x int );
Table created.
Elapsed: 00:00:00.03
SQL> create or replace view v1 as select * from t;
View created.
Elapsed: 00:00:00.06
SQL> create or replace view v2 as select t.x xx, v1.x yy from
v1, t;
View created.
Elapsed: 00:00:00.06
SQL> create or replace view v3 as select v2.*, t.x xxx, v1.x
yyy from v2, v1, t;
View created.
Elapsed: 00:00:00.07
SQL>
SQL>
SQL> select lpad(' ',lvl*2,' ') || rowner || '.' || rname ||
'(' || rtype || ')' hierarchy
2 from table( cast(depends('V3','VIEW') as myTableType ) );
HIERARCHY
OPS$TKYTE.V3(VIEW)
OPS$TKYTE.T(TABLE)
OPS$TKYTE.V1(VIEW)
OPS$TKYTE.T(TABLE)
OPS$TKYTE.V2(VIEW)
OPS$TKYTE.T(TABLE)
OPS$TKYTE.V1(VIEW)
OPS$TKYTE.T(TABLE)
8 rows selected.
Message was edited by:
460425

Different ways to copy data between two schemas in one instance

Hi there,
I am searching a good way to copy data between two schemas in the same instance.
Both schemas have an identical structure such as triggers, tables, views and so on. The only difference is the purpose: one is the productivity system and one is for development.
I looked at datapump but I do not explicit want to export / import. I want to keep the data in the productivity schema as well as copy it to the other schema. Any ideas? I found out there is a copy statement but I dont't know how that works.
Thank you so far,
Jörn

Thank you for your replies!
I also thought of creating a second instance for development and move the dev - schema to it. I just don't know whether our server can handle both (performance?). Anyway the idea is to have a possibility to quickly rebuild the data inside a schema without indixes or triggers, just pure data. I thought the easiest way would be to copy the data between the schemas as they are exactly the same. However if you tell me DataPunp is the best solution i won't deny using it :).
When you export data a file is created. does that also mean that the exported data is deleted inside the schema?
best regards
Jörn
Ps: Guido, you are following me, aren' t you? ;-)

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