table
Stock:
ITEMID NUMBER PRIMARY KEY
DESCRIPTION VARCHAR2(30)
QUANTITY NUMBER
CREATE OR REPLACE TRIGGER trig_1 BEFORE
UPDATE OR INSERT ON stock
FOR EACH ROW
DECLARE
v_des VARCHAR2(30);
v_quan NUMBER;
BEGIN
SELECT
quantity,
description
INTO
v_quan,
v_des
FROM
stock;
IF v_quan <= 10 THEN
dbms_output.put_line('Restock' || v_des);
END IF;
END;
You need to use :NEW cursor to refer to the new value that is being inserted or updated as following:
CREATE OR REPLACE TRIGGER TRIG_1 BEFORE
UPDATE OR INSERT ON STOCK
FOR EACH ROW
BEGIN
IF :NEW.QUANTITY <= 10 THEN
DBMS_OUTPUT.PUT_LINE('Restock - ' || :NEW.DESCRIPTION);
END IF;
END;
/
Make sure that you SET SERVEROUTPUT ON while inserting/updating the table data so that it is displayed in the output.
Cheers!!
Related
create trigger calculation after insert on employee
for each row
begin
if :new.updated_sal is null
then
update employee set updated_sal= (10/100)* salary
where id=:new.id;
end if;
end;
I would like to create a trigger on the employee table, whenever a new record is inserted in the same table, a 10% of salary in the salary column should be calculated and put into another column updated_sal.
If I try to insert a new record, it is showing that the table is mutated, etc
It's just the :new pseudorecord you need:
create trigger calculation
after insert on employee
for each row
begin
if :new.updated_sal is null then
:new.updated_sal := (10/100) * :new.salary;
end if;
end;
You need to use before insert trigger,
And use :New.updated_sal:= :new.salary * somevalue
To assign salary.
I'm trying to find if there's more than 1 president in my database with a trigger and if yes, raise an error, I'm using hr, the table employees and I have to use the job_id to find it. Here's what my code looks like. Thanks!
CREATE OR REPLACE TRIGGER check_pres
BEFORE INSERT OR DELETE OR UPDATE ON employees
FOR EACH ROW
BEGIN
IF ((employees.job_id = 'AD_PRES') > 1)
THEN RAISE_APPLICATION_ERROR(-12345, 'More than one President in database.');
END IF;
END;
You should use Statement Level Trigger instead of Row Level Trigger by removing FOR EACH ROW expression
CREATE OR REPLACE TRIGGER check_pres
BEFORE INSERT OR DELETE OR UPDATE ON employees
DECLARE
v_cnt int;
BEGIN
SELECT COUNT(*) INTO v_cnt FROM employees WHERE job_id = 'AD_PRES';
IF ( v_cnt > 1 ) THEN
RAISE_APPLICATION_ERROR(-20345, 'More than one President in database.');
END IF;
END;
otherwise you'd get mutating error while getting the count value. Btw, the first argument value for RAISE_APPLICATION_ERROR should be between -20999 and -20000
I'm creating a update trigger where an employee can never have a salary that is greater than the president's. However I need to subquery the president's salary for comparison and the "new" updated employee's salary.
I originally had the the subquery using from the from employees table but had to make a new table because of the mutating table problem. I don't think creating a new table is plausible solution for a real implementation.
Is there a way I can save the president's salary without creating a new table?
CREATE OR REPLACE TRIGGER prevent_salary
BEFORE UPDATE ON employees
FOR EACH ROW
declare pres_sal number(8,2);
BEGIN
select salary into pres_sal from employees_salary where job_id='AD_PRES';--employees_salary was employees but that gives mutating error
IF (:new.salary > pres_sal)
THEN UPDATE employees
SET salary = :old.salary
WHERE employee_id = :old.employee_id;
END IF;
END;
One way to do it is to save off the president's salary in a BEFORE STATEMENT trigger and then use that in the FOR EACH ROW trigger.
"Compound Triggers", which have been around at least since version 11.1, offer a nice way to do that all in one place.
Here is an example:
CREATE OR REPLACE TRIGGER prevent_salary
FOR UPDATE OF salary ON employees
COMPOUND TRIGGER
pres_sal NUMBER;
BEFORE STATEMENT IS
BEGIN
select salary
into pres_sal
from employees
where job_id='AD_PRES';
END BEFORE STATEMENT;
BEFORE EACH ROW IS
BEGIN
:new.salary := least(:new.salary, pres_sal);
END BEFORE EACH ROW;
END prevent_salary;
You may try this :
CREATE OR REPLACE TRIGGER prevent_salary
BEFORE UPDATE ON employees
FOR EACH ROW
declare pres_sal number(8,2);
BEGIN
select salary into pres_sal from employees_salary where job_id='AD_PRES';--employees_salary was employees but that gives mutating error
IF (:new.salary > pres_sal)
Raise_Application_Error (-20101, 'An employee''s salary couldn''t exceed president''s !');
END IF;
END;
I'm trying to create a compound trigger to avoid the mutation problem.
I've a table and a python's procedure that perfoms a transaction insert. The table has n fields.
What I´m trying to do is when a value of one of those fields is negative, then do not perform the operation , and insert the value from the previous record of the field (prior to insert) of the table. Another concern is that one of the fields is and id, to distinguish between sites.
For no, this is the code I've, Considering only one field (KWHGEN):
CREATE OR REPLACE TRIGGER "CIRCU3".D_measures_TP_test
--FOR INSERT OR UPDATE ON T_MEASURES_TP_NEW
FOR INSERT ON T_MEASURES_TP_NEW
COMPOUND TRIGGER
VAL_KWHGEN NUMBER(21,2);
VAL_autoin NUMBER (19,0);
AFTER EACH ROW IS
BEGIN
SELECT autoin, KWHGEN INTO VAL_ID_MED, VAL_KWHGEN FROM
(SELECT *
FROM T_measures_TP_NEW WHERE ID_site = :NEW.ID_site
ORDER BY TIMESTAMP DESC)
WHERE ROWNUM = 1;
IF :NEW.KWHGEN <0
THEN UPDATE T_MEASURES_TP_NEW SET KWHGEN = VAL_KWHGEN WHERE autoin = VAL_autoin;
END IF;
END AFTER EACH ROW;
END D_MEASURES_TP_test;
But the mutation error is following me ;-)
You have created trigger on T_MEASURES_TP_NEW and then updating same table T_MEASURES_TP_NEW within trigger. This will again call your trigger.
If the first select in trigger again returns negative value in VAL_KWHGEN then mutating error will follow you.
You defined only an AFTER EACH block, nothing else. This is the same as creating a row-level trigger (i.e. using FOR EACH ROW)
It must be like this (not tested):
CREATE OR REPLACE TRIGGER "CIRCU3".D_measures_TP_test
FOR INSERT ON T_MEASURES_TP_NEW
COMPOUND TRIGGER
VAL_KWHGEN NUMBER(21,2);
VAL_autoin NUMBER (19,0);
TYPE RowIdTableType IS TABLE OF ROWID;
TYPE KWHGENTableType IS TABLE OF T_MEASURES_TP_NEW.KWHGEN%TYPE;
RowIdTable RowIdTableType;
KWHGENTable KWHGENTableType;
BEFORE STATEMENT IS
BEGIN
RowIdTable := RowIdTable();
KWHGENTable := KWHGENTableType();
END BEFORE STATEMENT;
BEFORE EACH ROW IS
BEGIN
RowIdTable.EXTEND;
RowIdTable(RowIdTable.LAST) := :NEW.ROWID;
KWHGENTable.EXTEND;
KWHGENTable(RowIdTable.LAST) := :NEW.KWHGEN;
END BEFORE EACH ROW;
AFTER STATEMENT IS
BEGIN
FOR i IN RowIdTable.FIRST..RowIdTable.LAST LOOP
SELECT
DISTINCT MIN(autoin) OVER (ORDER BY TIMESTAMP DESC),
DISTINCT MIN(KWHGEN) OVER (ORDER BY TIMESTAMP DESC)
INTO VAL_ID_MED, VAL_KWHGEN
FROM T_measures_TP_NEW
WHERE ROWID = RowIdTable(i);
IF KWHGENTable(i) < 0
THEN UPDATE T_MEASURES_TP_NEW
SET KWHGEN = VAL_KWHGEN
WHERE autoin = VAL_autoin;
END IF;
END LOOP;
END AFTER STATEMENT;
END;
/
OK, I do have a solution:
1.- Create a package where record the new insert data (BEFORE)
create or replace PACKAGE PCK_MEDIDAS_TP AS
TYPE DATOS_MEDIDAS_TP IS RECORD(
v_id_sede NUMBER (10,0),
v_id_med NUMBER (10,0),
v_kwhGEN NUMBER (21,2),
v_timestamp TIMESTAMP
);
type T_MEDTP is table of DATOS_MEDIDAS_TP index by binary_integer;
tabla_medidas_tp T_MEDTP;
END PCK_MEDIDAS_TP;
2.- Create a procedure each row (BEFORE) to read the new insert data and then record them into de package's table.
create or replace TRIGGER "CIRCU3".D_MEDIDAS_TP_test
BEFORE INSERT ON T_MEDIDAS_TP_NEW
FOR EACH ROW
DECLARE
Indice binary_integer;
BEGIN
--AUTOINCREMENTAL DEL CAMPO ID_MEDIDAS
SELECT T_MEDIDAS_TP_NEW_SEQ.NEXTVAL INTO :NEW.id_MEDIDAS_OLD FROM DUAL;
Indice:= PCK_MEDIDAS_TP.tabla_medidas_tp.COUNT+1;
PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_id_sede := :NEW.ID_SEDE;
PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_id_med := :NEW.ID_MEDIDAS;
PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_kwhGEN := :NEW.KWHGEN;
PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_timestamp := :NEW.TIMESTAMP;
IF :NEW.KWHGEN <0 THEN
DBMS_OUTPUT.put_line('first trigger:' ||:NEW.ID_MEDIDAS||','||:NEW.ID_SEDE||','||:NEW.TIMESTAMP);
-- INSERT INTO TEST_TRIGGER VALUES ('100', :NEW.KWHGEN, SYSDATE);
--ELSE DBMS_OUTPUT.PUT_LINE('¿?');
END IF;
END;
3.- Create a statement procedure (AFTER) where you can check your condition, in my case if kwhgen <0. If is true, I'll read the previous record in the original tbale and update the insert record with taht value.
create or replace TRIGGER D_MEDIDAS_TP_TEST_STATEMENT
AFTER INSERT ON T_MEDIDAS_TP_NEW
DECLARE
Indice binary_integer;
s_id_sede NUMBER (10,0);
s_id_med NUMBER (10,0);
s_kwhGEN NUMBER (21,2);
s_timestamp TIMESTAMP;
BEGIN
FOR Indice in 1..PCK_MEDIDAS_TP.tabla_medidas_tp.count LOOP
DBMS_OUTPUT.put_line('second trigger: kwhgen: '||PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_kwhGEN||', id_sede: '||PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_id_sede);
IF PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_kwhGEN <0 THEN
DBMS_OUTPUT.put_line('second trigger: v_kwhGEN is negative');
SELECT prev_KWHGEN INTO s_kwhgen
from(
SELECT LEAD (KWHGEN,1) over (ORDER BY id_medidas desc) as prev_KWHGEN
FROM T_MEDIDAS_TP_NEW WHERE ID_SEDE = PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_id_sede
ORDER BY id_medidas DESC) where rownum =1;
INSERT INTO TEST_TRIGGER VALUES ('100', '5555', SYSDATE);
DBMS_OUTPUT.put_line('second trigger. KWHGEN: '||s_kwhGEN);
DBMS_OUTPUT.put_line('UPDATE');
UPDATE T_MEDIDAS_TP_NEW SET KWHGEN = S_KWHGEN WHERE ID_MEDIDAS = PCK_MEDIDAS_TP.tabla_medidas_tp(Indice).v_id_med;
else DBMS_OUTPUT.put_line('¿?');
END IF;
END LOOP;
PCK_MEDIDAS_TP.tabla_medidas_tp.delete; -- vaciamos la tabla
END;
I am trying to create a trigger. It is supposed to update any new date entry to sysdate. So far, I have the following code. However, I get "invalid table name" and "SQL statement ignored" errors.
CREATE OR REPLACE TRIGGER new_orders
AFTER INSERT ON orders
FOR EACH ROW
BEGIN
IF INSERTING THEN
UPDATE
SET order_date := SYSDATE;
END IF;
END;
/
CREATE OR REPLACE TRIGGER new_orders
BEFORE INSERT ON orders
FOR EACH ROW
BEGIN
:NEW.order_date := SYSDATE;
END;
/