Hello fellow programmers and happy new year to you all!
I have few university tasks for winter break and one of them is to create trigger on table:
PERSON(ID, Name, Surname, Age);
Trigger is supposed to inform user when they have inserted row with invalid ID. Vadility criteria is that ID is 11 digits long.
I tried to write solution like this:
CREATE OR REPLACE TRIGGER person_id_trigg
AFTER INSERT
ON person
DECLARE
idNew VARCHAR(50);
lengthException EXCEPTION;
BEGIN
SELECT id INTO idNew FROM INSERTED;
IF LENGTH(idNew) <> 11 THEN
RAISE lengthException;
END IF;
EXCEPTION
WHEN lengthException THEN
dbms_output.put_line('ID for new person is INVALID. It must be 11 digits long!');
END;
Then I realized that INSERTED exists only in sqlserver and not in oracle.
What would you suggest I could do to fix that?
Thanks in advance!
Do you want to raise an exception (which would prevent the insert from succeeding)? Or do you want to allow the insert to succeed and write a string to the dbms_output buffer that may or may not exist and may or may not be shown to a human running the insert?
In either case, you'll want this to be a row-level trigger, not a statement-level trigger, so you'll need to add the for each row clause.
CREATE OR REPLACE TRIGGER person_id_trigg
AFTER INSERT
ON person
FOR EACH ROW
If you want to raise an exception
BEGIN
IF( length( :new.id ) <> 11 )
THEN
RAISE_APPLICATION_ERROR( -20001,
'The new ID value must have a length of 11' );
END IF;
END;
If you want to potentially print output but allow the insert to succeed
BEGIN
IF( length( :new.id ) <> 11 )
THEN
dbms_output.put_line( 'The new ID value must have a length of 11' );
END IF;
END;
Of course, in reality, you would never use a trigger for this sort of thing. In the real world, you would use a constraint.
Related
Sorry for the delay! I've taken a workload greater then i can handle these couple weeks.
Ok, lets clarify things up!
There is a proprietary software running on top of it and
I do not have de ability to change this software! Actually it allows me to do a few things.
In this specific case I can not create a relation 1>N, I can not create a new table! What I do can is create fields.
So, how do i customize things? Through the database! Using triggers, functions and procedures. I know its a bad "work around" but it's what i got and works flawlessly 99% of times. Any exception my code throws the application shows on the screen!
The problem is actually the update not working.
You ask:
Why you're looping when you're forcing there to only be one iteration (unless P_QTDLINHAS can be < 1 I suppose?)
R: Couse the user can select multiple lines in the application but I dont want them to do it. So a throw an error on the screen.
Why you have nested begin/end blocks.
R: Couse I may have to throw exceptions, I got used to write begin Statements Exception some message end.
Sample data:
CREATE TABLE SAMPLE_DATA
(
PKNUMBER NUMBER NOT NULL
, DESCRIPTION VARCHAR2(20)
, GROUPTOCHANGE VARCHAR2(100)
, STATUS VARCHAR2(1 BYTE)
, CONSTRAINT SAMPLE_DATA_PK PRIMARY KEY
(
PKNUMBER
)
ENABLE
);
INSERT INTO sample_data VALUES (1000,'ORDER1',NULL,NULL);
INSERT INTO sample_data VALUES (2000,'ORDER2',NULL,NULL);
INSERT INTO sample_data VALUES (3000,'ORDER3',NULL,NULL);
INSERT INTO sample_data VALUES (4000,'ORDER4','1000,2000,30001',NULL);
In this case the field GROUPTOCHANGE will be filled by the user like this "2108,8090,8843". Each number represents a PKNUMBER in same table "SAMPLE_DATA".
yes i know! the user can type something wrong.. let's ignore this for now!
The field STATUS will eventually be updated to 'C','L','R' OR NULL. When this happens I Need this logic to be executed:
IF OLD.STATUS <> NEW.STATUS AND GROUPTOCHANGE IS NOT NULL THEN
UPDATE SAMPLE_DATA SP
SET SP.STATUS = :NEW.STATUS
WHERE SP.PKNUMBER IN (:NEW.GROUPTOCHAGE)
AND PS.GROUPTOCHANGE IS NULL;
END IF;
Dispite the bad design is it possible to do?
Thank for any help!!
Here what I've done so far:
create or replace PROCEDURE "AD_LIBERA_FRETES_FILHOS"(
P_CODUSU NUMBER,
P_IDSESSAO VARCHAR2,
P_QTDLINHAS NUMBER,
P_MENSAGEM OUT VARCHAR2)
AS
P_NUNOTA NUMBER(10);
P_CONTROLE VARCHAR(100);
P_PEDIDOS VARCHAR(100);
P_STATUS VARCHAR(100);
BEGIN
-- avoid more than 1 at a time
IF (P_QTDLINHAS > 1) THEN
RAISE_APPLICATION_ERROR(-20000, 'SELECIONE APENAS UM PEDIDO PARA EXECUTAR ESTA AÇÃO.');
END IF;
FOR I IN 1..P_QTDLINHAS LOOP
--extract param from session
P_NUNOTA := ACT_INT_FIELD(P_IDSESSAO, I, 'PKNUMBER');
P_STATUS := ACT_TXT_FIELD(P_IDSESSAO, I, 'STATUS');
--verify typed text should be "84090,89830,83393..."
BEGIN
SELECT REGEXP_REPLACE(CAB.GROUPTOCHANGE, '[0-9-, ]', ''),
CAB.GROUPTOCHANGE
INTO P_CONTROLE,
P_PEDIDOS
FROM SAMPLE_DATA CAB
WHERE CAB.PKNUMBER = P_NUNOTA;
END;
IF (P_CONTROLE IS NOT NULL) THEN
RAISE_APPLICATION_ERROR(-20000, '<B> SOMETHING WRONG !</B>');
ELSE
--perform de update (not working)
BEGIN
UPDATE SAMPLE_DATA C
SET C.STATUS = P_STATUS
WHERE
C.GROUPTOCHANGE IS NULL AND
C.PKNUMBER IN
(WITH DATA AS
(SELECT CAB.GROUPTOCHANGE STR
FROM SAMPLE_DATA CAB
WHERE CAB.PKNUMBER = P_NUNOTA )
SELECT TRIM(REGEXP_SUBSTR(STR, '[^,]+', 1, LEVEL)) STR
FROM DATA CONNECT BY INSTR(STR, ',', 1, LEVEL - 1) > 0);
END;
END IF;
END LOOP;
--mgs to show
P_MENSAGEM := 'DONE!! CHECK -> '||P_PEDIDOS;
END;
I am trying to implement a statement level trigger to enforce the following "An applicant cannot apply for more than two positions in one day".
I am able to enforce it using a row level trigger (as shown below) but I have no clue how to do so using a statement level trigger when I can't use :NEW or :OLD.
I know there are alternatives to using a trigger but I am revising for my exam that would have a similar question so I would appreciate any help.
CREATE TABLE APPLIES(
anumber NUMBER(6) NOT NULL, /* applicant number */
pnumber NUMBER(8) NOT NULL, /* position number */
appDate DATE NOT NULL, /* application date*/
CONSTRAINT APPLIES_pkey PRIMARY KEY(anumber, pnumber)
);
CREATE OR REPLACE TRIGGER app_trigger
BEFORE INSERT ON APPLIES
FOR EACH ROW
DECLARE
counter NUMBER;
BEGIN
SELECT COUNT(*) INTO counter
FROM APPLIES
WHERE anumber = :NEW.anumber
AND to_char(appDate, 'DD-MON-YYYY') = to_char(:NEW.appDate, 'DD-MON-YYYY');
IF counter = 2 THEN
RAISE_APPLICATION_ERROR(-20001, 'error msg');
END IF;
END;
You're correct that you don't have :OLD and :NEW values - so you need to check the entire table to see if the condition (let's not call it a "constraint", as that term has specific meaning in the sense of a relational database) has been violated:
CREATE OR REPLACE TRIGGER APPLIES_AIU
AFTER INSERT OR UPDATE ON APPLIES
BEGIN
FOR aRow IN (SELECT ANUMBER,
TRUNC(APPDATE) AS APPDATE,
COUNT(*) AS APPLICATION_COUNT
FROM APPLIES
GROUP BY ANUMBER, TRUNC(APPDATE)
HAVING COUNT(*) > 2)
LOOP
-- If we get to here it means we have at least one user who has applied
-- for more than two jobs in a single day.
RAISE_APPLICATION_ERROR(-20002, 'Applicant ' || aRow.ANUMBER ||
' applied for ' || aRow.APPLICATION_COUNT ||
' jobs on ' ||
TO_CHAR(aRow.APPDATE, 'DD-MON-YYYY'));
END LOOP;
END APPLIES_AIU;
It's a good idea to add an index to support this query so it will run efficiently:
CREATE INDEX APPLIES_BIU_INDEX
ON APPLIES(ANUMBER, TRUNC(APPDATE));
dbfiddle here
Best of luck.
Your rule involves more than one row at the same time. So you cannot use a FOR ROW LEVEL trigger: querying on APPLIES as you propose would hurl ORA-04091: table is mutating exception.
So, AFTER statement it is.
CREATE OR REPLACE TRIGGER app_trigger
AFTER INSERT OR UPDATE ON APPLIES
DECLARE
cursor c_cnt is
SELECT 1 INTO counter
FROM APPLIES
group by anumber, trunc(appDate) having count(*) > 2;
dummy number;
BEGIN
open c_cnt;
fetch c_cnt in dummy;
if c_cnt%found then
close c_cnt;
RAISE_APPLICATION_ERROR(-20001, 'error msg');
end if;
close c_cnt;
END;
Obviously, querying the whole table will be inefficient at scale. (One of the reasons why triggers are not recommended for this sort of thing). So this is a situation in which we might want to use a compound trigger (assuming we're on 11g or later).
I have a table that i'm trying to populate via a plsql script (runs on plsql developer). The actual DML statement
is contained in a procedure inside a package. The procedure only inserts if the record doesn't exist yet.
It doesn't work. The part that checks for existence returns true after the first iteration of the script loop even if it doesn't actually exist in the table.
If i put the commit outside of the loop, nothing gets inserted at all and the existence checks return true for all iteration even if the table it empty.
When i try to simplify the insert with existence check to be in just one statement without the exception handling, i get the same outcome.
Please tell me what I'm doing wrong here.
CREATE OR REPLACE PACKAGE BODY some_package
IS
PROCEDURE add_to_queue(id IN NUMBER)
IS
pending_record VARCHAR2(1);
BEGIN
-- this part succeeds even if nothing matches the criteria
-- during the loop in the outside script
SELECT 'Y'
INTO pending_record
FROM dual
WHERE EXISTS (SELECT 'x' FROM some_queue smq
WHERE smq.id = id AND smq.status IS NULL);
EXCEPTION
WHEN NO_DATA_FOUND THEN
INSERT INTO some_queue (seqno, id, activity_date)
VALUES (some_sequence.nextval, id, SYSDATE);
WHEN OTHERS THEN
NULL;
END;
END some_package;
CREATE TABLE some_queue
(
seqno VARCHAR2(500) NOT NULL,
id NUMBER NOT NULL,
activity_date DATE NOT NULL,
status VARCHAR2(25),
CONSTRAINT some_queue_pk PRIMARY KEY (seqno)
);
-- script to randomly fill in the table with ids from another table
declare
type ids_coll_tt is table of number index by pls_integer;
ids_coll_table ids_coll_tt;
cursor ids_coll_cur is
select tab.id
from (select *
from ids_source_table
order by dbms_random.value ) tab
where rownum < 10;
begin
open ids_coll_cur;
fetch ids_coll_cur bulk collect into ids_coll_table;
close ids_coll_cur;
for x in 1..ids_coll_table.count
loop
some_package.add_to_queue(ids_coll_table(x));
commit; -- if this is here, the first iteration gets inserted
end loop;
-- commit; -- if the commit is done here, nothing gets inserted
end;
Note: I translated this code to be more generic for posting. Forgive me if there are any typos.
Update: even if i put everything inside the script and not use the package, i'm not able to properly check for existence and I get the same results.
I figured out the solution:
CREATE OR REPLACE PACKAGE BODY some_package
IS
PROCEDURE add_to_queue(p_id IN NUMBER)
IS
pending_record VARCHAR2(1);
BEGIN
-- this part succeeds even if nothing matches the criteria
-- during the loop in the outside script
SELECT 'Y'
INTO pending_record
FROM dual
WHERE EXISTS (SELECT 'x' FROM some_queue smq
WHERE smq.id = p_id AND smq.status IS NULL);
EXCEPTION
WHEN NO_DATA_FOUND THEN
INSERT INTO some_queue (seqno, id, activity_date)
VALUES (some_sequence.nextval, p_id, SYSDATE);
WHEN OTHERS THEN
NULL;
END;
END some_package;
changing the parameter name fixed it. I guess the compiler gets confused if it's the same name as the table field.
Don't name the parameter the same as the column (use a prefix like p_ or in_) and you can do it in a single statement if you use a MERGE statement self-joining on the ROWID pseudo-column:
CREATE OR REPLACE PACKAGE BODY some_package
IS
PROCEDURE add_to_queue(
in_id IN NUMBER
)
IS
BEGIN
MERGE INTO some_queue dst
USING ( SELECT ROWID AS rid
FROM some_queue
WHERE id = in_id
AND status IS NULL ) src
ON ( src.rid = dst.ROWID )
WHEN NOT MATCHED THEN
INSERT (seqno, id, activity_date)
VALUES (some_sequence.nextval, in_id, SYSDATE);
END;
END some_package;
I'm trying to figure out a simple ORACLE PL/SQL programming problem and I'm having some difficulties with it.
I have to make a trigger that catches inserts into a table, and if the location attribute of the new tuple getting into that table doesn't exist in the database, I need to throw a warning message and insert that new location into another table.
What I have now so far -
CREATE TRIGGER sightTrigger
AFTER INSERT ON SIGHTINGS
FOR EACH ROW
DECLARE
ct INTEGER;
BEGIN
SELECT COUNT(*)
INTO ct
FROM SIGHTINGS
WHERE SIGHTINGS.location <> :NEW.location;
IF ct > 0 THEN
RAISE_APPLICATION_ERROR('WARNING SIGN' || :NEW.location ||' does not exist in the database');
INSERT INTO FEATURES(LOCATION, CLASS, LATITUDE, ...)
VALUES (:NEW.LOCATION, 'UNKNOWN', ...);
END IF;
END;
I'm getting an error, "PLS-00306: wrong number of types of arguments in call to 'RAISE_APP_ERROR'. Could somebody tell me what's wrong? thank you
Try this:
RAISE_APPLICATION_ERROR(
-20001,
'WARNING SIGN' || :NEW.location || 'does not exist in the database'
);
Your RAISE_APPLICATION_ERROR takes two arguments (this is from Oracle docs): where error_number is a negative integer in the range -20000 .. -20999 and message is a character string up to 2048 bytes long.
I'm very new for trigger, now this what i was trying. I've two tables INSERTED and ORDER_INFO, both have the same column name ORDER_ID, ORDER_DATE. I've scenario, where client will be placing his/her order then, order information will be stored into INSERTED table, then by using this trigger, it'll insert into another table ORDER_INFO after satisfying the condition, which has been written.
create trigger tri_check
AFTER INSERT ON inserted FOR EACH ROW
DECLARE
v_date DATE;
BEGIN
SELECT order_date INTO v_date FROM inserted;
if (v_date)< (sysdate + 2) then
raiserror('You cannot take an order to be delivered less than 2 days from now',16, 1);
else
INSERT INTO orders_info
( order_id,order_date)
VALUES
(:new.order_id,v_date);
end if;
end;
But, when i'm executing the above trigger, then i'm getting this error.
ERROR at line 8: PL/SQL: SQL Statement ignored
6. SELECT order_date INTO v_date FROM inserted;
7. if (v_date)< (sysdate + 2) then
8. raiserror('You cannot take an order to be delivered less than 2 days from now',16, 1);
9. else
10. INSERT INTO orders_info
EDIT
Now, i made the same structure table into SYSTEM user, and got the same error. Table or View does not exist
Need help !! Thanks in advance !!
The message seems to indicate a problem with the 'raiserror' procedure. I'm not familiar with such a procedure in standard PL/SQL - did you mean RAISE_APPLICATION_ERROR? However, and perhaps more to the point, when using a trigger there's no need to do a SELECT from the table. All the data being inserted is available to the trigger. I suggest changing your trigger to be something like the following:
create trigger tri_check
AFTER INSERT ON inserted
REFERENCING NEW AS NEW
FOR EACH ROW
BEGIN
if :new.ORDER_DATE < sysdate + INTERVAL '2' DAY then
RAISE_APPLICATION_ERROR(-20000, 'You cannot take an order to be delivered less than 2 days from now');
else
INSERT INTO orders_info
(order_id, order_date)
VALUES
(:new.order_id, :new.ORDER_DATE);
end if;
end TRI_CHECK;
Share and enjoy.
You can just use the :NEW and :OLD values instead of your select:
CREATE TRIGGER tri_check
AFTER INSERT
ON inserted
FOR EACH ROW
DECLARE
BEGIN
IF :new.order_date < (SYSDATE + 2)
THEN
raiserror (
'You cannot take an order to be delivered less than 2 days from now',
16,
1);
ELSE
INSERT INTO orders_info (order_id, order_date)
VALUES (:new.order_id, :new.order_date);
END IF;
END;
What is your raiserror procedure? Do you have access permissions granted on it?
Hope it helps...
EDIT:
OK, from your error, and the error you posted on #Bob Jarvis' answer, you might not have INSERT privilege on the ORDERS_INFO table. You also should check your permissions on the INSERTED table too.
Check your permissions with your DBA.
If raiserror is not a defined procedure or you don't have access to it then use the RAISE_APPLICATION_ERROR method for raising an error as Bob suggests.