I have created the below trigger, but it is not getting fired after i am doing new insert/update in to the mentioned table:
CREATE OR REPLACE TRIGGER ref_upd_user_phi_details
AFTER
INSERT OR UPDATE --of emp_email_address, ssn_nb
ON ref_adp_employees
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
BEGIN
UPDATE ref_adp_employees
SET emp_email_address = 'QA_' ||emp_email_address,
ssn_nb = nvl2(ssn_nb, NULL, '123-45-6789')
WHERE upper(emp_email_address) NOT LIKE 'QA_%'
AND upper(emp_email_address) LIKE '%#KEENAN.COM';
exception
WHEN others
THEN
NULL;
END;
Can someone please suggest me what i am missing?
As #phonetic_man pointed out, you are hiding any error you get by catching when others and taking no action. Without the exception block you would see that you are causing a mutating table error (ORA-04091), because you are referring to the same table the trigger is against.
If you took out the for each row part to turn it into a statement-level trigger then you would avoid that issue, but now you would have an infinite loop (ORA-00036) - when you try to update the table from within the trigger, that update itself causes the same trigger to fire again; which tries to update the same table yet again, which causes the trigger to fire yet again; etc. until Oracle notices and kills the process.
It would make more sense to use a before-insert row-level trigger to make sure the new values for the row match whatever pattern you are trying to enforce. Maybe something like:
CREATE OR REPLACE TRIGGER ref_upd_user_phi_details
BEFORE INSERT OR UPDATE --of emp_email_address, ssn_nb
ON ref_adp_employees
REFERENCING OLD AS OLD NEW AS NEW
FOR EACH ROW
BEGIN
IF upper(:NEW.emp_email_address) NOT LIKE 'QA_%'
AND upper(:NEW.emp_email_address) LIKE '%#KEENAN.COM'
THEN
:NEW.emp_email_address := 'QA_' || :NEW.emp_email_address;
:NEW.ssn_nb := CASE WHEN :NEW.ssn_nb IS NULL THEN '123-45-6789' END;
END IF;
END;
/
And to see what it does:
insert into ref_adp_employees (emp_id, emp_email_address, ssn_nb) values (1, 'TEST_1', '123-45-6789');
insert into ref_adp_employees (emp_id, emp_email_address, ssn_nb) values (2, 'TEST_1#KEENAN.COM', '123-45-9876');
insert into ref_adp_employees (emp_id, emp_email_address, ssn_nb) values (3, 'QA_TEST_1', null);
select emp_id, emp_email_address, ssn_nb from ref_adp_employees;
EMP_ID EMP_EMAIL_ADDRESS SSN_NB
---------- ------------------------------ -----------
1 TEST_1 123-45-6789
2 QA_TEST_1#KEENAN.COM
3 QA_TEST_1
Not sure if you really intended to replace set SSNs with null, and turn nulls into the fixed value; I suspect you are really trying to replace set values with the fixed string and leaves nulls alone, in which case it would be:
:NEW.ssn_nb := CASE WHEN :NEW.ssn_nb IS NOT NULL THEN '123-45-6789' END;
You might also want to move that outside the IF block, so it's done regardless of the email address; I've replicated what your original code was trying to do but that might not be right.
If you have existing data that you want to modify to match these changes, do a one-off update of the whole table - don't try to do that inside a trigger.
Have you heard of Google? There's a myriad of answers and examples out there for triggers, but some things I see at this time:
1) Change trigger to BEFORE insert or update. Use AFTER when making changes to another table, or to run some subsequent process on the table.
2) Take out the comment to the individual fields being changed or added. That was good AFAIK.
3) In your body of the trigger use WHEN INSERTING and WHEN UPDATING. Or if you are just updating the table, change DDL to BEFORE UPDATE only.
4) In the update, reference with set :new.emp_email_address = 'QA_' || :old.emp_email_address ... and so on and so forth. That's where that old as old and new as new becomes important.
Kindly check if the trigger is valid or not by firing the below query..
SELECT *
FROM ALL_OBJECTS
WHERE OBJECT_NAME = trigger_name
AND OBJECT_TYPE = 'TRIGGER'
AND STATUS <> 'VALID'
The trigger is firing after update..
try before update
CREATE OR REPLACE TRIGGER ref_upd_user_phi_details
Before
INSERT OR UPDATE
Related
I am trying to create a row level trigger to delete a row if a value in the row is being made NULL. My business parameters state that if a value is being made null, then the row must be deleted. Also, I cannot use a global variable.
BEGIN
IF :NEW.EXHIBIT_ID IS NULL THEN
DELETE SHOWING
WHERE EXHIBIT_ID = :OLD.EXHIBIT_ID;
END IF;
I get the following errors:
ORA-04091: table ISA722.SHOWING is mutating, trigger/function may not see it
ORA-06512: at "ISA722.TRG_EXPAINT", line 7
ORA-04088: error during execution of trigger 'ISA722.TRG_EXPAINT'
When executing this query:
UPDATE SHOWING
SET EXHIBIT_ID = NULL
WHERE PAINT_ID = 5104
As already indicated this is a terrible idea/design. Triggers are very poor methods for enforcing business rules. These should be enforced in the application or better (IMO) by a stored procedure called by the application. In this case not only is it a bad idea, but it cannot be implemented as desired. Within a trigger Oracle does not permit accessing the table the trigger fired was fired on. That is what mutating indicates. Think of trying to debug this or resolve a problem a week later. Nevertheless this non-sense can be accomplished by creating view and processing against it instead of the table.
-- setup
create table showing (exhibit_id integer, exhibit_name varchar2(50));
create view show as select * from showing;
-- trigger on VIEW
create or replace trigger show_iiur
instead of insert or update on show
for each row
begin
merge into showing
using (select :new.exhibit_id new_eid
, :old.exhibit_id old_eid
, :new.exhibit_name new_ename
from dual
) on (exhibit_id = old_eid)
when matched then
update set exhibit_name = new_ename
delete where new_eid is null
when not matched then
insert (exhibit_id, exhibit_name)
values (:new.exhibit_id, :new.exhibit_name);
end ;
-- test data
insert into show(exhibit_id, exhibit_name)
select 1,'abc' from dual union all
select 2,'def' from dual union all
select 3,'ghi' from dual;
-- 3 rows inserted
select * from show;
--- test
update show
set exhibit_name = 'XyZ'
where exhibit_id = 3;
-- 1 row updated
-- Now for the requested action. Turn the UPDATE into a DELETE
update show
set exhibit_id = null
where exhibit_name = 'def';
-- 1 row updated
select * from show;
-- table and view are the same (expect o rows)
select * from show MINUS select * from showing
UNION ALL
select * from showing MINUS select * from show;
Again this is a bad option yet you can do. But just because you can doesn't mean you should. Or that you'll be happy with the result. Good Luck.
You have written a trigger that fires after or before a row change. This is in the middle of an execution. You cannot delete a row from the same table in that moment.
So you must write an after statement trigger instead that only fires when the whole statement has run.
create or replace trigger mytrigger
after update of exhibit_id on showing
begin
delete from showing where exhibit_id is null;
end mytrigger;
Demo: https://dbfiddle.uk/?rdbms=oracle_18&fiddle=dd5ade700d49daf14f4cdc71aed48e17
What you can do is create an extra column like is_to_be_deleted in the same table, and do this:
UPDATE SHOWING
SET EXHIBIT_ID = NULL, is_to_be_deleted = 'Y'
WHERE PAINT_ID = 5104;
You can use this parameter to implement your business logic of not showing the null details.
And later you can schedule a batch delete on that table to clean up these rows (or maybe archive it).
Benefit: you can avoid an extra unnecessary trigger on that table.
Nobody, will suggest you to use trigger to do this type of delete as it is expensive.
I need to write a trigger in Oracle PL/SQL (11g) before inserting each row that checks if a row exists: if it doesn't exists creates a new row, if it does exists updates the existing record.
Which is the best way to do that?
Thanks, Gianluca
What you want to do is a MERGE INTO:
MERGE INTO myTable t
USING (SELECT 'Smith' AS Name, 1 AS Id FROM DUAL) data -- put your data in here
ON (t.Id = data.Id) -- pk or other matching criteria
WHEN MATCHED
THEN
UPDATE SET t.name = data.name
WHEN NOT MATCHED
THEN
INSERT (Id, Name)
VALUES (data.Id, data.Name);
Buildiing a trigger is possible but no allowed/intended. You should't do this.
You'd try to abbort the insert and do something else. This is not a good idea, because of many thing: hidden logic in db, stupid-clients which are doing wrong things..
You can abort with an error, but it doesn't sound like you idea this way.
If you want to do it you could change to update. Never insert anything and implement a trigger before update, which checks if the row exists:
CREATE OR REPLACE TRIGGER myTableTrigger
BEFORE UPDATE
ON myTable
FOR EACH ROW
BEGIN
-- If row doesn't exist. Insert one before the update..
END;
Alternatively you could go the long way and build some views:
https://dba.stackexchange.com/questions/24047/oracle-abort-within-a-before-insert-trigger-without-throwing-an-exception
I need To update the field DATAMARKER"of my table LOG_ALARMA when I have one INSTER or UPDATE of "CONTADOR".
i have this, but return muting error.
create or replace TRIGGER TRIGGER2
AFTER INSERT OR UPDATE OF CONTADOR ON LOG_ALARMA
for each row
BEGIN
UPDATE LOG_ALARMA a
SET a.DATAMARKER=(SYSDATE);
END;
I look another examples and they work but i can't execute this correctly.
IF i comment the line for each row in my trigger body then it is working fine but it UPDATES all the rows in my table.
You do not issue an update SQL statement, because that would again cause the trigger to fire.
Instead, you just set the value :new.DATAMARKER to sysdate, using PL/SQL not SQL.
Make it a BEFORE INSERT OR UPDATE also.
CREATE TABLE Mutating
(
ID1 NUMBER,
DATE1 DATE
)
data present in a table is
ID1 DATE1
1 09/01/2015 14:09:14
1 08/31/2015 14:09:21
2 08/30/2015 14:09:30
Now i want to update the date1 if any update happens on id1 column in that situation i have used trigger look below.
CREATE OR REPLACE TRIGGER Mutating_trg
before INSERT OR DELETE OR UPDATE ON Mutating
referencing old as old new as new
for each row
begin
if updating then
:new.date1:=sysdate;
end if;
end;
then i have issued update statement
update set Mutating id1=6 where trunc(date1)=trunc(sysdate-2)
1 row updated
Now look into results
ID1 DATE1
1 09/01/2015 14:09:14
6 09/02/2015 14:09:14
2 08/30/2015 14:09:30
You should use before statement.
I am having problems with this code below, which is a trigger used in Oracle SQL:
CREATE OR REPLACE TRIGGER TRG_TUTOR_BLOCK
BEFORE INSERT OR UPDATE ON tutors
FOR EACH ROW
DECLARE
BEGIN
IF :new.tutorName = :old.tutorName
THEN
RAISE_APPLICATION_ERROR(-20101, 'A tutor with the same name currently exists.');
ROLLBACK;
END IF;
END;
/
This trigger is used to prevent users from entering the same tutor name at different records.
After I insert two records with the same tutorname, the trigger does not block me from inserting it. Is there anyone can tell me what are the problems with this coding? Here are the sample format and insert values:
INSERT INTO tutors VALUES (tutorID, tutorName tutorPhone, tutorAddress, tutorRoom, loginID);
INSERT INTO tutors VALUES ('13SAS01273', 'Tian Wei Hao', '019-8611123','No91, Jalan Wangsa Mega 2, 53100 KL', 'A302', 'TianWH');
Trigger in Kamil's example will throw ORA-04091, you can see this with your own eyes here. ROLLBACK in a trigger is unnecessary, it runs implicitly when a trigger makes a statement to fail.
You can prohibit any DML on table by altering it with read only clause:
alter table tutors read only;
At last, integrity should be declarated with integrity constraints and not with triggers.
Good luck!
You don't need a trigger for this in Oracle.
You can do it with an "unique index" on the tutorName column (see http://docs.oracle.com/cd/B28359_01/server.111/b28310/indexes003.htm#i1106547).
Note: about your trigger, it fails on checking for another record with the same tutorName because it's not scanning the tutors table for another record with the same tutorName, it's just comparing the tutorName values of the row you are creating (in this case, old.tutorName is just NULL, because the row doesn't exist yet).
Check the case in yours trigger body
IF :new.tutorName = :old.tutorName
It returns true only if 'tutorName' value is the same in new and old record. When you'll trying to updat some value you'll get
IF 'someTutorName' = 'someTutorName'
which will return TRUE.
Inserting row cannot fire this rule because you're trying to compare something like that:
'someTutorName' = NULL
This case always returns FALSE.
Try to use something like that
CREATE OR REPLACE TRIGGER TRG_TUTOR_BLOCK
BEFORE INSERT OR UPDATE ON tutors
FOR EACH ROW
DECLARE
rowsCount INTEGER;
BEGIN
SELECT COUNT(*) FROM tutors WHERE tutorName is :new.tutorName INTO rowsCount;
IF rowsCount > 0
THEN
RAISE_APPLICATION_ERROR(-20101, 'A tutor with the same name currently exists.');
ROLLBACK;
END IF;
END;
/
But the best solution is the one mentioned by friol - use unique index by executing SQL like this
ALTER TABLE tutors
ADD CONSTRAINT UNIQUE_TUTOR_NAME UNIQUE (tutorName);
If you wanna completely ignore recording a row to a table you can follow these steps
rename table to something else and create a view with the same name and create an instead of trigger.
create table usermessages (id number(10) not null)
GO
alter table usermessages rename to xusermessages
GO
create or replace view usermessages as (select * from xusermessages)
GO
create or replace trigger usermessages_instead_of_trg
instead of insert or update on usermessages
for each row
begin
Null ;
end ;
GO
insert into usermessages(123)
Live test available here below
http://sqlfiddle.com/#!4/ad6bc/2
When writing a row-level trigger in Oracle, I know that you can use the OLD and NEW pseudo-records to reference the old and new state of the row that fired the trigger. I know that in an INSERT trigger OLD doesn't contain any data, but I'm not sure how this affects the evaluation of a WHEN clause for that trigger. For example, if I have the following trigger:
CREATE OR REPLACE TRIGGER mung_row
BEFORE INSERT OR UPDATE ON some_table
FOR EACH ROW
BEGIN
:NEW.foo = 'some val';
END;
and I want to modify this trigger to only run on an update when foo was previously null, but always run on an insert, I could satisfy the update part of the change by adding a WHERE clause:
CREATE OR REPLACE TRIGGER mung_row
BEFORE INSERT OR UPDATE ON some_table
FOR EACH ROW
WHEN (OLD.foo IS NULL)
BEGIN
:NEW.foo = 'some val';
END;
Will this cause problems in the insert case? What will OLD.foo evaluate to in the INSERT?
I'm aware that I could split the INSERT and UPDATE triggers or use INSERTING/UPDATING/DELETING in the trigger body, but I'd rather not in the case that inspired this question.
When a record is being inserted, every field of OLD will be NULL, including the fields marked as NOT NULL in the table's definition.
For example, suppose your table has a non-nullable column named id:
CREATE TABLE some_table (
id NUMBER NOT NULL,
foo VARCHAR2(100)
)
When a record is inserted into this table, OLD.id will be NULL. However, when a record is updated in this table, OLD.id will not be NULL. Because you only want to change :NEW.foo if a record is being updated, you just have to check to see if OLD.id has a non-null value.
CREATE OR REPLACE TRIGGER mung_row
BEFORE INSERT OR UPDATE ON some_table
FOR EACH ROW
WHEN (OLD.id IS NOT NULL AND OLD.foo IS NULL)
BEGIN
:NEW.foo = 'some val';
END;