I'm taking my first steps in Pl/SQL and am struggling with triggers. I've tried creating the trigger below but am receiving this error:
Error at line 2: PL/SQL: SQL Statement ignored
PL/SQL: ORA-00942: table or view does not exist
To clarify: I have checked the name of the table over and over, and it does exist. It is also in the same schema as the trigger I'm trying to create. The 'customer_seq.NEXTVAL' refers to a sequence created previously that runs without errors.
The code is as follows:
CREATE TRIGGER new_customer
BEFORE INSERT ON customer
FOR EACH ROW
BEGIN
INSERT INTO customer_id VALUES ('c-', customer_seq.NEXTVAL);
END;
Thanks in advance for any help.
You probably intend something like this:
CREATE TRIGGER new_customer
BEFORE INSERT ON customer
FOR EACH ROW
BEGIN
SELECT customer_seq.NEXTVAL INTO :NEW.customer_id
FROM dual;
END;
It is unclear what the purpose of 'C_' is. If it is part of the customer id, I would advise you to stick to numbers.
Also note that more recent versions of Oracle support generated always as identity -- which is much preferred over defining a sequence and trigger.
Related
CREATE TRIGGER Comparer_Prix
BEFORE UPDATE ON ARTICLE
FOR EACH ROW BEGIN
SELECT ARTICLE.PRIXVENTE, ARTICLE.N_PRODUIT, ARTICLE.N_FABRICANT, LIEN_FABRICANT_PRODUIT.PRIXFABRICANT, LIEN_FABRICANT_PRODUIT.N_PRODUIT, LIEN_FABRICANT_PRODUIT.N_FABRICANT
FROM ARTICLE, LIEN_FABRICANT_PRODUIT
WHERE ARTICLE.N_FABRICANT=LIEN_FABRICANT_PRODUIT.N_FABRICANT AND ARTICLE.N_PRODUIT=LIEN_FABRICANT_PRODUIT.N_PRODUIT;
IF (NEW.PRIXVENTE< PRIXFABRICANT) THEN RAISE_APPLICATION_ERROR(-20001, 'Refusé');
END IF;
END;
I am trying to create a trigger that codes the following rule: the sales price must always be higher than the manufacturing price.
Here the errors I get:
Error(2,3): PL/SQL: SQL Statement ignored
Error(2,69): PL/SQL: ORA-00904: "LIEN_FABRICANT_PRODUIT"."PRIXFABRICANT" : invalid identifier
Error(2.92): PLS-00302: The component "PRIXFABRICANT" must be declared.
Error(5,3): PL/SQL: Statement ignored
Error(5,10): PLS-00201: the identifier 'NEW.PRIXVENTE' must be declared.
It is not new, but :new (you're missing a colon).
Though, that's not the only issue here; you can't select from a table which is just being modified; mutating table error is expected. Lucky you, you don't have to select from article as you can reference its values using the same :new value.
ORA-00904 means that you've used a column name which doesn't exist in that table. As you didn't post tables' descriptions, I'm simply repeating what you wrote. Fix it yourself.
Something like this:
create or replace trigger comparer_prix
before update on article
for each row
declare
l_prixfabricant lien_fabricant_produit.prixfabricant%type;
begin
select prixfabricant
into l_prixfabricant
from lien_fabricant_produit
where n_fabricatn = :new.n_fabricant
and n_produit = :new.n_produit;
if :new.prixvente < l_prixfabricant then
raise_application_error(-20001, 'Refusé');
end if;
end;
/
Also, it wouldn't harm if you learnt how to properly format code and make it easier to read. Use table aliases (instead of those lengthy table names).
If You compare two tables use:
... WHERE ... AND EXISTS(SELECT * FROM <TAB_COMPARE>)
I am new to PLSQL in Oracle. When I am learning about triggers, I have read from this source https://www.techonthenet.com/oracle/triggers/before_insert.php which says that when I create a BEFORE INSERT Trigger in Oracle, the FOR EACH ROW is NOT always needed, hence the syntax is enclosed by square brackets [ ]. I have written this simple trigger:
CREATE OR REPLACE TRIGGER enroll_time
BEFORE INSERT
ON ENROLL
FOR EACH ROW
BEGIN
:new.addtime := sysdate;
END;
/
If I remove the FOR EACH ROW in the above, I actually get an error:
Error report -
ORA-04082: NEW or OLD references not allowed in table level triggers
04082. 00000 - "NEW or OLD references not allowed in table level triggers"
*Cause: The trigger is accessing "new" or "old" values in a table trigger.
*Action: Remove any new or old references.
From the error message, it seems like if I use :new.[column_name], then FOR EACH ROW must have to exist. Why is this? Is there any example that FOR EACH ROW is NOT needed in a BEFORE INSERT TRIGGER in Oracle?
Is there any example that FOR EACH ROW is NOT needed in a BEFORE INSERT TRIGGER in Oracle?
Simple example of statement level trigger:
CREATE TABLE test_table(col VARCHAR2(10));
CREATE OR REPLACE TRIGGER enroll_time
BEFORE INSERT
ON ENROLL
BEGIN
INSERT INTO test_table(col)
SELECT 1 FROM dual;
END;
/
I highly recommend to read about compound trigger to understand when each part is fired.
Basically, if you need to use :OLD or :NEW pseudotables, you need a row level trigger. An example of a statement level trigger would be inserting a record into a table when another table is effected.
I'm trying to get my head around triggers, but I'm getting errors
Error(2,4): PL/SQL: SQL Statement ignored
Error(2,8): PL/SQL: ORA-00922: missing or invalid option
when creating the following trigger:
CREATE TRIGGER TableTrigger
AFTER UPDATE ON TestTable
FOR EACH ROW
BEGIN
set serveroutput on format wrapped;
DBMS_OUTPUT.put_line('TABLE UPDATED!');
END;
Which works on the following table:
CREATE TABLE TestTable
(
test1 INT,
test2 INT,
test3 INT,
PRIMARY KEY (test1)
);
I'm not sure what to do, does anyone have any suggestions?
Using DBMS_OUTPUT in triggers is not best practice. If you want to see that something was done create a logging table or an audit history table or set auditing of update on for that table.
DBMS_OUTPUT is useful when you are running a PL/SQL procedure or package from SQLPlus or other IDE.
Different versions of SQL may or may not show you the output of the buffer from a trigger.
I'm using pl\sql developer and I have a report table with a number(38) ID column.
I want to keep track of all updates for this table so I created another table like this:
CREATE TABLE reportUpdate (report_id number(38), updatedate number(32));
And I created a trigger:
CREATE or REPLACE TRIGGER BeforeUpdateReport
BEFORE
UPDATE ON REPORT
FOR EACH ROW
Begin
INSERT INTO reportUpdate
Values(old.ID,sysdate);
END;
And when I run it, I get an error, saying: trigger 'SYSTEM.BEFOREUPDATEREPORT' is invalidand failed re-validation.
Can someone please help
You can use show errors after you see compiled with warnings, or query the user_errors view to see what is wrong later.
One obvious thing is that you haven't prefixed the old reference with a colon:
CREATE or REPLACE TRIGGER BeforeUpdateReport
BEFORE
UPDATE ON REPORT
FOR EACH ROW
Begin
INSERT INTO reportUpdate
Values(:old.ID,sysdate);
END;
/
It's also better to specify the target table fields in the insert statement:
INSERT INTO reportUpdate (report_id, updatedate)
Values(:old.ID,sysdate);
But you have update_date defined in your table creation script as number(32), which doesn't make sense. As #realspirituals pointed out, it should be:
CREATE TABLE reportUpdate (report_id number, updatedate date);
I need help on creating a trigger on my table1
that will insert specific columns into table2 from table1.
How can i do that? I am using Oracle 11G XE .
Here is my code:
create trigger AllowanceTrigger
on ex_bulacan
after insert
as
insert into allowance VALUES (PLANT_ORIGIN,SO_NO, SO_STATUS,SO_REMARKS,DRIVER_NAME)
select plant_origin, sales_order_no, status,remarks, driver_name
from ex_bulacan;
go ;
When I run that command I get this error
ORA-04071: missing BEFORE, AFTER or INSTEAD OF keyword
The explanation is:
ORA-04071. 00000 - "missing BEFORE, AFTER or INSTEAD OF keyword"
*Cause: The trigger statement is missing the BEFORE/AFTER/INSTEAD OF clause.
*Action: Specify either BEFORE, AFTER or INSTEAD OF.
There is no "go" statement in PL/SQL, and you have not followed the correct syntax for a trigger definition (it is well documented)
Try this:
create trigger AllowanceTrigger
after insert on ex_bulacan
begin
insert into allowance (PLANT_ORIGIN,SO_NO, SO_STATUS,SO_REMARKS,DRIVER_NAME)
select plant_origin, sales_order_no, status,remarks, driver_name
from ex_bulacan;
end;
I'm not sure whether it does what you intended. It fires once per insert statement, not for each row, and it inserts all rows from ex_bulacan into allowance, not just the ones you just inserted. Maybe what you want is actually:
create trigger AllowanceTrigger
after insert on ex_bulacan
for each row
begin
insert into allowance (PLANT_ORIGIN,SO_NO, SO_STATUS,SO_REMARKS,DRIVER_NAME)
values (:new.plant_origin, :new.sales_order_no, :new.status, :new.remarks,
:new.driver_name);
end;
There is a syntax error in your code. You must specify the trigger in this order:
CREATE TRIGGER AllowanceTrigger
AFTER INSERT
ON ex_bulacan