I have a trigger that looks something like this:
create or replace
TRIGGER cluster_check
before insert on my_table
FOR EACH ROW
when (passive_server = new.server)
begin
ROLLBACK;
UPDATE my_table
set (server,passive_server) = (passive_server,server) where passive_server = new.server;
end;
I am getting the error Error: ORA-04076: invalid NEW or OLD specification on compilation.
Essentially what I am trying to do is check on insert to see if the incoming server matches the passive server in another record and if so cancel the insert and swap the existing records passive and active servers.
What am I doing wrong?
A trigger on a table can't change the operation like this.
You could define a view on top of my_table, do the INSERT against the view, and then have an instead of insert trigger that changed the INSERT operation into an UPDATE. But then all your DML would have to go against the view rather than the table. You could potentially rename the table and then create a view named my_table to make that transition easier.
Before you go down that path, however, are you certain that you need a trigger in the first place? Are you sure that your application couldn't do something like call a stored procedure that would determine what to do or that it couldn't do a MERGE instead of an INSERT?
Related
I have a table named info_1,with 3 columns those are id,name,and operation.
Now when we insert or update a row, a trigger fires to fill the operation column with the kind of triggering event we are performing, i.e either insert or update.. I am unable to create such a trigger where user only gives information about id,name and operation column fills by itself through trigger. need help.
You can set the operation using a case statement like this:
create or replace trigger info_1_tr
before insert or update on info_1
for each row
begin
:new.operation := case when updating then 'UPDATE' else 'INSERT' end;
end;
/
I have a trigger:
create or replace trigger trig
before insert on sistem
for each row
declare
v_orta number;
begin
SELECT v_orta INTO :new.orta_qiymet
FROM sistem;
v_orta:=(:new.riyaziyyat+:new.fizika)/2;
insert into sistem(orta_qiymet)
values(v_orta);
end trig;
When I insert a row:
insert into sistem(riyaziyyat,fizika) values(4,4)
I get an error:
Why am I getting that error?
This is fundamentally not understanding how triggers work. You can't generally select from the table the trigger is against, and a before-insert trigger shouldn't not insert into the same table again - as that would just cause the trigger to fire again, infinitely (until Oracle notices and stops it). You aren't even currently using the v_orta value you're attempting to query.
I suspect you think the trigger is instead of your original insert perhaps, and really you want to set the orta_qiymet value in the newly-inserted row automatically based on the other two columns you have supplied. To do that you don't (and can't) select those values; instead you refer to the :NEW pseudorecord as you are already doing, and then set the third column value in that same pseudorow:
create or replace trigger trig
before insert on sistem
for each row
begin
:new.orta_qiymet := (:new.riyaziyyat + :new.fizika)/2;
end trig;
/
There is a lot of information in the documentation; this is similar to one of the examples.
I am new to Oracle and would like to know how to make this trigger work please. I can do each trigger separately but I need them all in the same one if that makes sense.
create trigger ID_trigger
before insert on crime, evidence, offence, officer
for each row
begin
select crime_seq.nextval into :new.crime_id from dual
and officer_seq.nextval into :new.officer_id from dual
and evidence_seq.nextval into :new.evidence_id from dual
and offence_seq.nextval into :new.offence_id from dual;
end;
I initially had a single trigger for each table. However when submitting data into my form the triggers seemed to have overwritten the previous one
" I initially had a singler trigger for each table, however when
sumbitting data into my form the triggers seemed to have overwritten
the previous one"
Let's guess: you called all four triggers id_trigger. Each subsequent CREATE OR REPLACE TRIGGER call would overwrite the first one. Unless you used CREATE TRIGGER as you do here, in which case each subsequent call would fail, Either way, only one table would have a trigger.
You see, even though they belong to a table, triggers are separate database objects. So, like indexes or constraints, their names must be unique within the schema.
The solution is simple: give each trigger a different name, say by including the table name.
I created the trigger to update the oracle data base table after insert.
CREATE OR REPLACE TRIGGER Update_ACU
AFTER INSERT ON TBL_ACU
FOR EACH ROW
BEGIN
UPDATE TBL_ACU
SET CURRENCY = 'XXX'
WHERE ACCOUNT like '%1568';
END ;
I inserted record as
insert into TBL_ACU values('23','USD','1231568');
I am getting table ORACLE Mutating trigger error.
Please help me how to resolve this.
It would be better to use BEFORE INSERT trigger to do this.
Try like this,
CREATE OR REPLACE
TRIGGER update_acu
BEFORE INSERT ON tbl_acu
FOR EACH ROW
WHEN (NEW.ACCOUNT LIKE '%1568')
BEGIN
:NEW.currency := 'XXX';
END ;
Well, you cannot modify the table from the trigger if the trigger is called upon modification of that table. There are various solutions to this problem including an AFTER STATEMENT trigger and caching modifications in some collection defined in PL/SQL PACKAGE, howewer in your situation I'd rather change the body of your trigger to this:
BEGIN
IF :NEW.ACCOUNT LIKE '%1568' THEN
:NEW.CURRENCY := 'XXX';
END IF;
END;
You can use the :NEW and :OLD variables inside the trigger, which identify the new and old values of the record accordingly. Modifying values of the :NEW record will cause changes in data actually inserted to the database.
The below code is giving a mutating error.
Can any1 pls help in solving this.
CREATE OR REPLACE TRIGGER aso_quote_cuhk_trigger
BEFORE INSERT
ON aso.aso_quote_headers_all
FOR EACH ROW
BEGIN
UPDATE aso.aso_quote_headers_all
SET quote_expiration_date=sysdate+90
where quote_header_id=:new.quote_header_id;
END;
/
In oracle there are two levels of triggers: row level and table level.
Row level triggers are executed for each row. Table level triggers executed per statement, even if a statement changed more then one row.
In a row level trigger, you cannot select/update the table itself that has the trigger: you will get a mutating error.
In this case, there is no need for an UPDATE statement. Just try this:
CREATE OR REPLACE TRIGGER aso_quote_cuhk_trigger
BEFORE INSERT
ON aso.aso_quote_headers_all
FOR EACH ROW
BEGIN
:new.quote_expiration_date=sysdate+90;
END;
/
EDIT Rajesh mentioned it is possible, that before inserting a new row, OP wants to update all other records in the aso_quote_headers_all table.
Well, this is feasible, but it's a little tricky. To do this properly, you will need
A pl/sql package and a variable in the package header that is modified by the triggers. This variable could be a list holding the IDs of newly inserted records. Row level after insert trigger would add a new ID to the list. The content of this package variable will be different for each different session, so let's call this variable session_variable.
Row level after insert trigger, that would add new ID to the session_variable.
Table level after insert trigger that would get IDs from the session_variable, process the ID and then remove it from the session_variable. This trigger could execute necessary selects/updates on the aso_quote_headers_all. After a newly inserted ID is processed, this trigger should make sure it gets removed from the session_variable.
I realise you must have resolved your issue by now. However I am adding this answer below to help anyone else facing similar problem as you and I faced.
I recently encountered mutating table (ORA-04091: table XXXX is mutating, trigger/function may not see it) issue and after searching around realised the Compound Triggers feature available in 11g. If you're on 11g following compound trigger would have solved your issue.
CREATE OR REPLACE TRIGGER aso_quote_cuhk_trigger
FOR INSERT ON aso.aso_quote_headers_all
COMPOUND TRIGGER
row_id rowid;
AFTER EACH ROW IS
BEGIN
row_id := :new.rowid;
END AFTER EACH ROW;
AFTER STATEMENT IS
BEGIN
UPDATE aso.aso_quote_headers_all
SET quote_expiration_date = sysdate+90
WHERE rowid = row_id;
END AFTER STATEMENT;
END aso_quote_cuhk_trigger;
/
A word about how it works. This compound trigger fires 2 events :
First is AFTER EACH ROW where we capture the rowid of newly inserted row
Next is AFTER STATEMENT where we update the table using rowid (captured during first event) in the WHERE clause.
A useful link if you want to read more about Compound Triggers.