I have created a trigger, that will autoincrement the id, according to the sequence, every time a new record is inserted. Like this:
create sequence test_seq
start with 1
increment by 1
nomaxvalue;
--drop trigger test_trigger;
create or replace trigger test_trigger
before insert on myTable
for each row
begin
select test_seq.nextval into :new.tab_id from dual;
end;
However, I'd like to insert a factorial of the row index instead. How could I achieve this?
Edit:
create or replace trigger test_trigger
after insert on myT
for each row
begin
select fac(test_seq.nextval) into :new.tab_id from dual;
end;
Added fac function which works fine:
create or replace function fac(n in number)
return number
is
v number :=1;
begin
for i in 1..n
loop
v :=v * i;
end loop;
return v;
end;
But I still only see 1,2,3,4 in the table instead of 1,2,6,24...
From Oracle's documentation. You want to use a BEFORE trigger in this instance, an AFTER trigger won't actually change the table's data just from setting it in NEW:
Because the trigger uses the BEFORE keyword, it can access the new
values before they go into the table, and can change the values if
there is an easily-corrected error by assigning to :NEW.column_name.
My guess is that you are still seeing the same old values from the sequence because your BEFORE trigger still exists; the AFTER trigger won't change those values.
So what you want is the following:
CREATE OR REPLACE TRIGGER test_trigger
BEFORE INSERT ON myt
FOR EACH ROW
BEGIN
SELECT FAC(test_seq.nextval) INTO :new.tab_id FROM dual;
END;
/
I think as of Oracle 11g (or maybe it's 10g; can't remember) you can also do the following:
CREATE OR REPLACE TRIGGER test_trigger
BEFORE INSERT ON myt
FOR EACH ROW
BEGIN
:new.tab_id := FAC(test_seq.nextval);
END;
/
Do something like
create function factorial (n integer) return integer as
...
create or replace trigger test_trigger
after insert on mytable
-- don't do this for each row
begin
update mytable set
tab_id = factorial((select count(*) from mytable))
where tab_id is null;
end;
/
Related
I'm new with oracle sql. I am trying to make a trigger that counts when X user performs an update or an insert, but the TRANSACTIONCONTROL table shows it like this:
DATE--------- USER-----------INSERT----UPDATE
10/03/2022 UserParcial 1 0
10/03/2022 UserParcial 0 1
10/03/2022 UserParcial 1 0
But I want it to look like this:
DATE--------- USER-----------INSERT----UPDATE
10/03/2022 UserParcial 2 1
This is my trigger:
create or replace NONEDITIONABLE TRIGGER TRANSACTIONCONTROL_Trig
AFTER INSERT OR DELETE OR UPDATE on products
for each row
DECLARE
dataTran date;
userTran varchar(30);
InsertTran number:=0;
UpdateTran number:=0;
BEGIN
SELECT SYSDATE INTO dateTran FROM DUAL;
SELECT USER INTO userTran FROM DUAL;
IF INSERTING THEN
InsertTran := InsertTran +1;
INSERT INTO TransactionControl(date, user, insert, updates)
VALUES(dateTran, userTran, insertTran, updateTran);
END IF;
IF UPDATING THEN
updateTran:= updateTran+1;
INSERT INTO TransactionControl(date, user, insert, updates)
VALUES(dateTran, userTran, insertTran, updateTran);
END IF;
END;
If you don't need exact numbers, than mining ALL_TAB_MODIFICATIONS periodically could probably suffice. (I'm curious as to what business function having the count provides)
But if you really must use a trigger, then a compound trigger lets you keep counts at row level, but then summarise at statement level.
Some pseudo code below
create or replace trigger mytrig
for insert or update on mytable
compound trigger
ins_cnt int;
upd_cnt int;
before statement is
begin
ins_cnt := 0;
upd_cnt := 0;
end before statement;
after each row is
begin
if inserting then ins_cnt := ins_cnt + 1; end if;
if updating then upd_cnt := upd_cnt + 1; end if;
end after each row;
after statement is
begin
insert into txn_control ( ... ) values (ins_cnt, upd_cnt);
end after statement;
end;
/
CREATE TABLE table_001(
Day_date date
);
CREATE TABLE table_002(
new_Day_date date
);
CREATE OR REPLACE TRIGGERS trigger
AFTER INSERT ON table_001
FOR EACH ROW
BEGIN
INSERT INTO table_002 VALUES(SYSDATE)
END;
You have a few syntax errors. It's not "TRIGGERS". Also, give a valid trigger name. A semicolon was missing after the insert.
CREATE OR REPLACE TRIGGER trigger_name
AFTER INSERT ON table_001
FOR EACH ROW
BEGIN
INSERT INTO table_002(new_Day_date) VALUES(SYSDATE);
END;
/
CREATE OR REPLACE TRIGGER trigger_name
AFTER INSERT ON table_001
FOR EACH ROW
BEGIN
INSERT INTO table_002 VALUES(SYSDATE);
END;
I need to create an oracle sequence with specific values
FOUR0001, FOUR0002, FOUR0003.....
the increment must be in order.
First create a simple sequence
create sequence my_seq ; --start with 1 increment by 1
In your application code / table where you use the sequence to store the data, use something like this
INSERT INTO yourtab (col1) VALUES( 'FOUR'||lpad(my_seq.nextval,4,'0'));
You could create a sequence:
create sequence SEQ_NAME ...;
and then to create a trigger to feed the field automatically:
CREATE OR REPLACE TRIGGER INS_TABLENAME
before insert on TABLENAME
for each row
BEGIN
if :new.FIELD_NAME is null then
:new.FIELD_NAME := 'FOUR'||lpad(SEQ_NAME.nextval,4,'0');
end if;
END;
I've created a sequence starting with 210 ( because i already ahve 209 records) then created the trigger bellow
CREATE OR REPLACE trigger BIU_FRS
before insert or update on FOURNISSEUR
for each row
begin
if :NEW.FRS_NUM is null then
select ('FOUR'||lpad(four_seq.nextval,4,'0')) into :NEW.FRS_NUM from dual;
end if;
if inserting then
:new.created := localtimestamp;
:new.created_by := nvl(wwv_flow.g_user,user);
end if;
:new.updated := localtimestamp;
:new.updated_by := nvl(wwv_flow.g_user,user);
end;
thank you #Kaushik Nayak and #Diego Souza
I'm trying to execute the following SQL statement on Oracle 11g. I'm not experienced when it comes to Oracle and I'm not sure why this is failing. This query was provided to me by our developer.
I was attempting to execute this through the SQL worksheet in OEM.
CREATE OR REPLACE TRIGGER TBL_ADMINCOMMAND_TRG BEFORE
INSERT OR UPDATE ON tbl_AdminCommands FOR EACH ROW
BEGIN
IF inserting
AND :new.ADMINCOMMANDID IS NULL THEN
SELECT TBL_ADMINCOMMANDS_SEQ.nextval INTO :new.ADMINCOMMANDID FROM DUAL;
END IF;
END;
ALTER TRIGGER TBL_ADMINCOMMAND_TRG ENABLE;
The code you show works for me, but only as two separate commands:
1)
CREATE OR REPLACE TRIGGER TBL_ADMINCOMMAND_TRG BEFORE
INSERT OR UPDATE ON tbl_AdminCommands FOR EACH ROW
BEGIN
IF inserting
AND :new.ADMINCOMMANDID IS NULL THEN
SELECT TBL_ADMINCOMMANDS_SEQ.nextval INTO :new.ADMINCOMMANDID FROM DUAL;
END IF;
END;
2)
ALTER TRIGGER TBL_ADMINCOMMAND_TRG ENABLE;
Try doing them one at a time.
As an aside, this line:
SELECT TBL_ADMINCOMMANDS_SEQ.nextval INTO :new.ADMINCOMMANDID FROM DUAL;
can be simplified to this in 11G:
:new.ADMINCOMMANDID := TBL_ADMINCOMMANDS_SEQ.nextval;
In fact, the whole trigger can be simplified to:
CREATE OR REPLACE TRIGGER TBL_ADMINCOMMAND_TRG
BEFORE INSERT ON tbl_AdminCommands
FOR EACH ROW
WHEN (NEW.ADMINCOMMANDID IS NULL)
BEGIN
:new.ADMINCOMMANDID := TBL_ADMINCOMMANDS_SEQ.nextval;
END;
If you are using SQL*Plus, you should end your PL/SQL commands with a single forward slash on a line by itself:
CREATE OR REPLACE TRIGGER TBL_ADMINCOMMAND_TRG
BEFORE INSERT OR UPDATE ON tbl_AdminCommands
FOR EACH ROW
BEGIN
IF inserting AND :new.ADMINCOMMANDID IS NULL
THEN
SELECT TBL_ADMINCOMMANDS_SEQ.nextval
INTO :new.ADMINCOMMANDID
FROM DUAL;
END IF;
END;
/
ALTER TRIGGER TBL_ADMINCOMMAND_TRG ENABLE;
Also note that if your trigger uses IF inserting you could do only a trigger BEFORE INSERT.
the problem is this :
I implemented a trigger on the table called CLAN_AFFILIATI that increases (if inseriemento) and decreases (in case of cancellation) an attribute (NUMAFFILIATI) of another table called CLAN. what I would do is block the update NUMAFFILIATI of Clan by the user and had thought to r another trigge on CLAN that did this:
trigger on CLAN_AFFILIATI(CLAN VARCHAR,AFFILIATO VARCHAR,RUOLO VARCHAR)
CREATE OR REPLACE TRIGGER "AggiornamentoNumAffiliati"
AFTER INSERT OR DELETE ON CLAN_AFFILIATI
FOR EACH ROW
DECLARE
CLAN_APPARTENENZA VARCHAR(20);
BEGIN
IF INSERTING THEN
SELECT NOME INTO CLAN_APPARTENENZA
FROM CLAN
WHERE NOME=:new.CLAN;
UPDATE CLAN
SET NUMAFFILIATI=NUMAFFILIATI+1
WHERE CLAN_APPARTENENZA=NOME;
ELSE
SELECT NOME INTO CLAN_APPARTENENZA
FROM CLAN
WHERE NOME=:old.CLAN;
UPDATE CLAN
SET NUMAFFILIATI=NUMAFFILIATI-1
WHERE CLAN_APPARTENENZA=NOME;
END IF;
END;
trigger on CLAN (NAME VARCHAR ,NUMAFFILIATI INTEGER)
CREATE OR REPLACE TRIGGER "ModificaNumAffiliati"
BEFORE INSERT OR UPDATE OF NUMAFFILIATI ON CLAN
FOR EACH ROW
DECLARE
CONT NUMBER:=0;
BEGIN
IF INSERTING THEN
IF :new.NUMAFFILIATI <> 0 THEN
RAISE_APPLICATION_ERROR(-20016,'NUMERO ERRATO');
END IF;
ELSE
SELECT COUNT(*) INTO CONT
FROM CLAN_AFFILIATI
WHERE :old.NOME=CLAN;
IF CONT <> :new.NUMAFFILIATI THEN
RAISE_APPLICATION_ERROR(-20017,'NUMERO ERRATO');
END IF;
END IF;
END;
but so I'm doing is reporting an error:
error ORA-04091: Table ANTONIO.CLAN_AFFILIATI is being modified, the trigger / function can not read
ORA-06512: at "ANTONIO.ModificaNumAffiliati", line 10
ORA-04088: error during execution of trigger 'ANTONIO.ModificaNumAffiliati'
ORA-06512: at "ANTONIO.AggiornamentoNumAffiliati", line 12
ORA-04088: error during execution of trigger 'ANTONIO.AggiornamentoNumAffiliati
how can I solve this problem ....
This is propably solution:
I tested it with this sample tables:
CREATE TABLE CLAN_AFFILIATI(CLAN VARCHAR2(100),AFFILIATO VARCHAR2(100),RUOLO VARCHAR2(100));
CREATE TABLE CLAN (NOME VARCHAR2(100) ,NUMAFFILIATI NUMBER(10));
You need this helper package.
CREATE OR REPLACE PACKAGE STORE_NOMES
AS
TYPE record_nomes IS RECORD (
nome VARCHAR2(100),
operation VARCHAR2(100) -- insert or delete
);
TYPE array_type_nomes IS TABLE OF record_nomes INDEX BY BINARY_INTEGER;
g_array_nomes array_type_nomes;
END STORE_NOMES;
/
Trigger on CLAN table:
CREATE OR REPLACE TRIGGER MODIFICANUMAFFILIATI
BEFORE INSERT OR UPDATE OF NUMAFFILIATI ON CLAN
FOR EACH ROW
DECLARE
l_CONT NUMBER:=0;
BEGIN
IF INSERTING THEN
-- prevent inserting <> 0
IF :new.NUMAFFILIATI <> 0 THEN
RAISE_APPLICATION_ERROR(-20016,'NUMERO ERRATO');
END IF;
ELSE
SELECT COUNT(*) INTO l_CONT
FROM CLAN_AFFILIATI
WHERE CLAN = :old.NOME;
IF l_CONT <> :new.NUMAFFILIATI THEN
RAISE_APPLICATION_ERROR(-20017,'NUMERO ERRATO');
END IF;
END IF;
END;
/
Before statement trigger on CLAN_AFFILIATI table:
CREATE OR REPLACE TRIGGER TRG_CLAN_AFFILIATI_BEFORE_STMT
BEFORE INSERT OR DELETE
ON CLAN_AFFILIATI
DECLARE
BEGIN
STORE_NOMES.g_array_nomes.DELETE;
END;
/
After statement trigger on CLAN_AFFILIATI table:
CREATE OR REPLACE TRIGGER TRG_CLAN_AFFILIATI_AFTER_STMT
AFTER INSERT OR DELETE
ON CLAN_AFFILIATI
DECLARE
BEGIN
FOR i IN STORE_NOMES.g_array_nomes.FIRST..STORE_NOMES.g_array_nomes.LAST LOOP
IF(STORE_NOMES.g_array_nomes(i).operation = 'INSERTING') THEN
UPDATE CLAN
SET NUMAFFILIATI=NUMAFFILIATI+1
WHERE NOME = STORE_NOMES.g_array_nomes(i).NOME;
ELSIF(STORE_NOMES.g_array_nomes(i).operation = 'DELETING') THEN
UPDATE CLAN
SET NUMAFFILIATI=NUMAFFILIATI-1
WHERE NOME = STORE_NOMES.g_array_nomes(i).NOME;
END IF;
END LOOP;
END;
/
Row Insert/Delete trigger on CLAN_AFFILIATI table:
CREATE OR REPLACE TRIGGER AGGIORNAMENTONUMAFFILIATI
BEFORE INSERT OR DELETE ON CLAN_AFFILIATI
FOR EACH ROW
DECLARE
l_CLAN_APPARTENENZA VARCHAR(20);
BEGIN
IF INSERTING THEN
SELECT NOME INTO l_CLAN_APPARTENENZA
FROM CLAN
WHERE NOME = :new.CLAN;
STORE_NOMES.g_array_nomes(STORE_NOMES.g_array_nomes.COUNT).nome := :new.CLAN;
STORE_NOMES.g_array_nomes(STORE_NOMES.g_array_nomes.LAST).operation := 'INSERTING';
ELSE
SELECT NOME INTO l_CLAN_APPARTENENZA
FROM CLAN
WHERE NOME = :old.CLAN;
STORE_NOMES.g_array_nomes(STORE_NOMES.g_array_nomes.COUNT).nome := :old.CLAN;
STORE_NOMES.g_array_nomes(STORE_NOMES.g_array_nomes.LAST).operation := 'DELETING';
END IF;
END;
/
Now working this (without ORACLE-EXCEPTION):
INSERT INTO CLAN(NOME, NUMAFFILIATI) VALUES('Antonio', 0);
INSERT INTO CLAN_AFFILIATI(CLAN,AFFILIATO,RUOLO) values('Antonio','Affiliato1','Ruolo1');
INSERT INTO CLAN_AFFILIATI(CLAN,AFFILIATO,RUOLO) values('Antonio','Affiliato2','Ruolo2');
Change the first trigger "AggiornamentoNumAffiliati" so that it doesn't immediately try to update clan, but stores the name (NOME) in a PL/SQL-Table within a Package; then, you make an AFTER INSERT OR DELETE (but without the FOR EACH ROW clause) trigger that reads the PL/SQL table from the package and updates the CLANs accordingly.
I don't have my developer tools with me, but it looks to me as though your getting yourself into a cyclic dependency issue of sorts. When your CLAN_AFFILIATI trigger is raised, in it you do an update of CLAN which calls the second trigger, which has a select from the CLAN_AFFILIATI table in the ELSE block.
Maybe the before insert (first query), and after insert(second query) have an affect also.
ORA-04091 is also known as a "mutating table" error - basically, row triggers cannot query or alter the table on which the trigger operates.
#Martin's answer is the classic description of how to work around this issue, but it you're on Oracle 11+ you can use a compound trigger to do the same thing.
Share and enjoy.