I am trying to create a trigger that checks if the faculty member to be added to the assigned table will is already on the qualified table for a specified class. Perhaps this is a tedious method. Nevertheless, I'd still like to know what I'm doing wrong. The following is my code with created the created tables and the trigger being the last part of the code:
CODE:
CREATE TABLE Faculty (
FId varchar(10),
FName varchar(20),
CONSTRAINT Faculty_ID_pk PRIMARY KEY(FId)
);
CREATE TABLE Course (
CId varchar(10),
CName varchar(20),
CONSTRAINT Course_ID_pk PRIMARY KEY(CId)
);
CREATE TABLE Qualify (
QDate DATE,
FId varchar(10),
CId varchar(10),
CONSTRAINT Qualifying_date CHECK(QDate >= TO_DATE('2020-08-24', 'YYYY-MM-DD')),
CONSTRAINT Qualify_FID_fk FOREIGN KEY(FId) REFERENCES Faculty(FId),
CONSTRAINT Qualify_CID_fk FOREIGN KEY(CId) REFERENCES Course(CId)
);
CREATE TABLE Assign (
ADate DATE,
FId varchar(10),
CId varchar(10),
CONSTRAINT Qualifying_check CHECK(ADate > TO_DATE('2020-08-24', 'YYYY-MM-DD')),
CONSTRAINT Assign_FID_fk FOREIGN KEY(FId) REFERENCES Faculty(FId),
CONSTRAINT Assign_CID_fk FOREIGN KEY(CId) REFERENCES Course(CId)
);
CREATE OR REPLACE TRIGGER Check_If_Qualified
BEFORE INSERT ON Assign
FOR EACH ROW
DECLARE
v_facNum number;
BEGIN
SELECT f.FId
into v_facNum
from Faculty f
where f.facnum = :new.fid;
END;
However, I keep receiving an error saying:
Error at line 7: PLS-00225: subprogram or cursor 'F' reference is out of scope
v_facNum number;
BEGIN
SELECT f.FId
into v_facNum
from Faculty f
Does anyone know what could be wrong?
There are lots of issues in your code. You can check the count of records into FACULTY table and use that count for whatever logic you want.
CREATE OR REPLACE TRIGGER CHECK_IF_QUALIFIED
BEFORE INSERT ON ASSIGN
FOR EACH ROW
DECLARE
CNT NUMBER;
BEGIN
SELECT COUNT(1)
INTO CNT
FROM FACULTY
WHERE FACNUM = :NEW.FID;
END;
/
That would be something like this (sample tables are really just a sample; they are here to make the trigger compile):
SQL> create table assign (fid number);
Table created.
SQL> create table faculty (facnum number, fid number);
Table created.
SQL> CREATE OR REPLACE TRIGGER Check_If_Qualified
2 BEFORE INSERT ON Assign
3 FOR EACH ROW
4 DECLARE
5 v_facNum number;
6 BEGIN
7 SELECT f.FId
8 into v_facNum
9 from Faculty f
10 where f.facnum = :new.fid;
11
12 -- now do something with v_facNum
13 END;
14 /
Trigger created.
SQL>
Related
I am currently working under postgres 14.
I got two tables customers and contacts, and i want to automatically find the customer_id from the customer name when i add a new contact in the table contacts.
CREATE TABLE customers(
customer_id INT GENERATED ALWAYS AS IDENTITY,
customer_name VARCHAR(255) NOT NULL UNIQUE,
PRIMARY KEY(customer_id)
);
CREATE TABLE contacts(
contact_id INT GENERATED ALWAYS AS IDENTITY,
customer_id INT,
contact_name VARCHAR(255) NOT NULL UNIQUE,
PRIMARY KEY(contact_id),
CONSTRAINT fk_customer
FOREIGN KEY(customer_id)
REFERENCES customers(customer_id)
);
INSERT INTO customers(customer_name) VALUES('my_first_customer')
So from here i want to do something like that :
INSERT INTO contacts(customer_id, contact_name ) VALUES('my_first_customer',"thomas")
and i want to get this result in contacts table :
contact_id
customer_id
contact_name
1
1
"thomas"
i tried to make a function to change the value from name to id but get an error of type.
Because the the type error is catch before the trigger. Here is my function
CREATE FUNCTION get_id_fct()
RETURNS TRIGGER AS $get_id_fct$
DECLARE val_id INTEGER;
BEGIN
SELECT customer_id INTO val_id FROM customers WHERE customers.customer_id = NEW.customer_id;
NEW.customer_id := val_id;
RETURN NEW
END
$get_id_fct$ LANGUAGE plpgsql;
CREATE TRIGGER get_id
BEFORE INSERT ON contacts
FOR EACH ROW EXECUTE PROCEDURE get_id_fct();'
Is their a way around that ? or specific method to do this task that i don't know about ?
I am quite a beginner at SQL.
You can make a subquery in insert statement
INSERT INTO contacts(customer_id, contact_name ) VALUES (
(select customer_id from customers where customer_name = 'my_first_customer') ,'thomas');
This query will fail if there is more than one customer with given name, and insert a null value for customer_id if there is no customers with given name
Different approach (proposed by #wildplasser)
INSERT INTO contacts(customer_id, contact_name )
select customer_id,'thomas' from customers where customer_name = 'my_first_customer';
In this case, when there is no customer with given name, no row will be created. When there is more than one customer with given name, for each of them record will be created.
Or you can create view with INSTEAD OF trigger.
create view v_contacts as
select customer_name, contact_name from customers
join contacts on customers.customer_id = contacts.customer_id;
CREATE FUNCTION emp () RETURNS trigger AS $$
BEGIN
INSERT INTO contacts(customer_id, contact_name )
VALUES((select customer_id from customers where customer_name =
NEW.customer_NAME),NEW.contact_NAME);
RETURN NULL;
END;
$$ LANGUAGE plpgsql;
CREATE TRIGGER v_contactst
INSTEAD OF INSERT ON v_contacts
FOR EACH ROW
EXECUTE FUNCTION emp();
Insert statement
INSERT INTO v_contacts(customer_name, contact_name ) VALUES('my_first_customer','thomas')
And just a note, that columns customer_name and contact_name are not unique so this code is not safe and throw error if customer_name didn't exists or there is more than one record with this customer_name
(zaposlenik means emplpoyee, godisnji_odmor means vacation)
So I want to make a trigger that triggers if an employee(here is called zaposlenik) has more than 21 days of vacation after an insert in year 2020. An employee can have multiple vacations(like 2 days, 10 days...) one to many relation between tables zaposlenik(employee) and godisnji_odmor(vacation). My problem here is that I don't know how to get that zaposlenik_id from the insert on which the trigger tiggers so I can sum up the vacation days of that employee on the ID = zaposlenik_id.
Here are my tables and trigger.
CREATE TABLE zaposlenik
(
zaposlenik_id INTEGER CONSTRAINT zaposlenik_pk PRIMARY KEY,
posao VARCHAR(30) NOT NULL,
ime VARCHAR(30) NOT NULL,
prezime VARCHAR(30) NOT NULL,
broj_tel INTEGER NOT NULL,
email VARCHAR(50) NOT NULL,
adresa VARCHAR(100) NOT NULL,
mjesecni_iznos_place FLOAT NOT NULL,
IBAN VARCHAR(34) NOT NULL,
budzet FLOAT,
parking_mjesto_id VARCHAR(5) CONSTRAINT zaposlenik_parking_mjesto_fk REFERENCES
parking_mjesto(etaza_i_br_mjesta),
zaposlenik_id_2 INTEGER CONSTRAINT zaposlenik_zaposlenik_fk REFERENCES
zaposlenik(zaposlenik_id)
);
CREATE TABLE godisnji_odmor
(
godisnji_odmor_id INTEGER CONSTRAINT godisnji_odmor_pk PRIMARY KEY,
pocetak DATE NOT NULL,
kraj DATE NOT NULL,
zaposlenik_id INTEGER NOT NULL CONSTRAINT godisnji_odmor_zaposlenik_fk REFERENCES
zaposlenik(zaposlenik_id)
);
CREATE OR REPLACE TRIGGER t_godisnji
AFTER INSERT
ON godisnji_odmor
DECLARE
v_br NUMBER; --sum of the vacation days
v_id NUMBER; -- id of the employee that is inserted (his id is zaposlenik_id)
BEGIN
SELECT zaposlenik_id INTO v_id FROM INSERTED;
SELECT SUM( g.kraj - g.pocetak ) INTO v_br
FROM zaposlenik z INNER JOIN godisnji_odmor g USING(zaposlenik_id)
WHERE g.pocetak > '01-JANUARY-2020' AND zaposlenik_id = v_id;
IF v_br > 21 THEN
ROLLBACK;
raise_application_error(-20100,'Godisnji prekoracuje 21 dan u sumi');
END IF;
END t_godisnji;
/
You need to use the :new for this as follows:
replace
SELECT zaposlenik_id INTO v_id FROM INSERTED;
with
v_id := :new.zaposlenik_id;
In short, You can have your code without v_id variable as follows:
CREATE OR REPLACE TRIGGER t_godisnji
AFTER INSERT
ON godisnji_odmor
DECLARE
v_br NUMBER; --sum of the vacation days
--v_id NUMBER; -- id of the employee that is inserted (his id is zaposlenik_id)
BEGIN
--SELECT zaposlenik_id INTO v_id FROM INSERTED;
SELECT SUM( g.kraj - g.pocetak ) INTO v_br
FROM zaposlenik z INNER JOIN godisnji_odmor g USING(zaposlenik_id)
WHERE g.pocetak > '01-JANUARY-2020'
AND zaposlenik_id = :new.zaposlenik_id; -- see the usage of :new here
IF v_br > 21 THEN
ROLLBACK;
raise_application_error(-20100,'Godisnji prekoracuje 21 dan u sumi');
END IF;
END t_godisnji;
/
i have two tables named as childs and parent.
create table parent(
wallet_id NUMBER generated always as identity,
amount int,
customer_id int,
primary key(wallet_id),
Foreign key (customer_id) REFERENCES childs(customer_id)
);
create table childs(
customer_id number generated always as identity,
name varchar2 (255)
);
Now what i wanted to achieve was to get name from childs , and assign a wallet_id to childs in parent table as parent table has a foreign key to customer_id.
For this purpose i created a trigger.
create or replace
TRIGGER TRIGGER1
AFTER INSERT ON CHILDS
Declare
id int;
BEGIN
select MAX(customer_id) into id FROM childs;
insert into parent (customer_id ) values ( id );
END;
Now trigger is created but when i insert value in childs,
insert into childs(names) values ('jarral');
Now following error appears:
SQL Error: ORA-04098: trigger 'SYSTEM.TRG' is invalid and failed re-validation
04098. 00000 - "trigger '%s.%s' is invalid and failed re-validation"
*Cause: A trigger was attempted to be retrieved for execution and was
found to be invalid. This also means that compilation/authorization
failed for the trigger.
*Action: Options are to resolve the compilation/authorization errors,
disable the trigger, or drop the trigger.
How can i solve that?
I'm not entirely sure I follow your question, but is this what you are after ?
SQL> create table t1 ( id number generated as identity , x int);
Table created.
SQL> create table t2 ( id number generated as identity , t1_id int);
Table created.
SQL>
SQL> create or replace
2 trigger trg
3 after insert on t1
4 for each row
5 begin
6 insert into t2 (t1_id) values ( :new.id);
7 end;
8 /
Trigger created.
SQL> insert into t1 (x) values ( 0);
1 row created.
SQL> select * from t1;
ID X
---------- ----------
1 0
SQL> select * from t2;
ID T1_ID
---------- ----------
1 1
I am implementing a library management system in SQL. I have the following table structure and some values inserted in them:
create table books
(
IdBook number(5),
NameBook varchar2(35),
primary key(IdBook)
);
create table users
(
IdUsers number(5),
NameUser varchar2(20),
primary key(IdUsers)
);
create table borrowed
(
IdBorrowed number(5),
IdUsers number(5),
IdBook number(5),
DueDate date,
DateReturned date,
constraint fk_borrowed foreign key(IdUsers) references users(IdUsers),
constraint fk_borrowed2 foreign key(IdBook) references books(IdBook)
);
insert into books values(0,'FairyTale');
insert into books values(1,'Crime and Punishment');
insert into books values(2,'Anna Karenina');
insert into books values(3,'Norwegian Wood');
insert into users values(01,'Robb Dora');
insert into users values(02,'Pop Alina');
insert into users values(03,'Grozavescu Teodor');
insert into users values(04,'Popa Alin');
insert into borrowed values(10,02,3,'22-Jan-2017',null);
insert into borrowed values(11,01,1,'25-Jan-2017','19-Dec-2016');
insert into borrowed values(12,01,3,'22-Jan-2017',null);
insert into borrowed values(13,04,2,'22-Jan-2017','13-Dec-2016');
What I want now is that my db to allow "borrowing" books for the users(i.e insert into the borrowed table) that have no unreturned books(i.e date returned is not null) and if they have unreturned books I want to abandon the whole process. I thought to implement this in the following way:
create or replace procedure borrowBook(IdBorrowed in number,IdUsers number,IdBook number,DueDate date,DateReturned date) as begin
if exists (SELECT u.IdUsers, u.NameUser, b.DateReturned
FROM users u, borrowed b
WHERE u.IDUSERS = b.IdUsers and DateReturned is not null),
insert into borrowed values(IdBorrowed,IdUsers,IdBook,DueDate,DateReturned);
end borrowBook;
The above procedure does not check if the parameter I pass to this function is the same as the one in my select and I do not know how to do this and correctly insert a value in my table.
Any help would be much appreciated. Thank in advance!
You should not name your parameters the same as columns also used inside the procedure.
You can also simplify your procedure to a single INSERT statement, no IF required:
create or replace procedure borrowBook(p_idborrowed in number, p_idusers number, p_idbook number, p_duedate date, p_datereturned date)
as
begin
insert into borrowed (idborrowed, idusers, idbook, duedate, datereturned)
select p_idborrowed, p_idusers, p_idbook, p_duedate, p_datereturned
from dual
where not exists (select *
from users u
join borrowed b on u.idusers = b.idusers
and b.datereturned is not null);
end borrowBook;
It's also good coding style to explicitly list the columns for an INSERT statement. And you should get used to the explicit JOIN operator instead of using implicit joins in the where clause.
What about this one:
create or replace procedure borrowBook( p_IdBorrowed in number ,
p_IdUsers number ,
p_IdBook number ,
p_DueDate date ,
p_DateReturned date )
as
begin
if (SELECT COUNT(*)
FROM borrowed
WHERE IDUSERS = p_IdUsers
AND DateReturned IS NULL) = 0 THEN
insert into borrowed values (p_IdBorrowed ,
p_IdUsers ,
p_IdBook ,
p_DueDate ,
p_DateReturned );
end if ;
end borrowBook;
You would seem to want something like this:
create or replace procedure borrowBook (
in_IdBorrowed in number,
in_IdUsers number,
in_IdBook number,
in_DueDate date,
in_DateReturned date
) as
v_flag number;
begin
select (case when exists (select 1
from borrowed b
where b.IdUsers = in_IdUsers and b.DateReturned is not null
)
then 1 else 0
end)
into v_flag
from dual;
if (flag = 0) then
insert into borrowed
values(in_IdBorrowed, in_IdUsers, in_IdBook, in_DueDate, v_DateReturned);
end if
end -- borrowBook;
I created this 4 tables:
create table terminatedEmployees (
empid number primary key,
dept number,
empname varchar2(50),
salary number
);
create table employees (
empid number primary key,
dept number,
empname varchar2(50),
salary number
);
create table payroll (
empid number primary key,
salary number,
CONSTRAINT fk_payemploy
FOREIGN KEY (empid)
REFERENCES employees(empid)
);
create table salaryAudit (
empid number primary key,
oldsal number,
newsal number,
datechanged date,
changedby varchar2(25),
CONSTRAINT fk_salaryaudit
FOREIGN KEY (empid)
REFERENCES employees(empid)
);
and now I'm trying to create a trigger in order to update two of them when employees table is updated:
CREATE TRIGGER trigger_updated_employees
AFTER UPDATE ON employees
FOR EACH ROW
when (old.salary != new.salary)
BEGIN
UPDATE INTO salaryAudit (newsal, oldsal)
VALUES(:new.salary, :old.salary);
UPDATE INTO payroll (salary)
VALUES(:new.salary);
END;
But I'm getting the error:
2/5 PL/SQL: SQL Statement ignored
2/12 PL/SQL: ORA-00903: invalid table name
4/5 PL/SQL: SQL Statement ignored
4/12 PL/SQL: ORA-00903: invalid table name
The three tables I'm calling in the trigger are ok and other triggers I created work...
Try something like this:
CREATE TRIGGER TRIGGER_UPDATED_EMPLOYEES
AFTER UPDATE ON EMPLOYEES
FOR EACH ROW
WHEN (OLD.SALARY <> NEW.SALARY)
BEGIN
MERGE INTO PAYROLL p
USING (SELECT :NEW.EMPID AS EMPID FROM DUAL) d
ON (p.EMPID = d.EMPID)
WHEN NOT MATCHED THEN
INSERT (EMPID, SALARY)
VALUES (:NEW.EMPID, :NEW.SALARY)
WHEN MATCHED THEN
UPDATE
SET SALARY = :NEW.SALARY;
MERGE INTO SALARYAUDIT a
USING (SELECT :NEW.EMPID AS EMPID FROM DUAL) d
ON (a.EMPID = d.EMPID)
WHEN NOT MATCHED THEN
INSERT (EMPID, OLDSAL, NEWSAL, DATECHANGED, CHANGEDBY)
VALUES (:NEW.EMPID, :OLD.SALARY, :NEW.SALARY, SYSDATE, 'SOME_USER')
WHEN MATCHED THEN
UPDATE
SET OLDSAL = :OLD.SALARY,
NEWSAL = :NEW.SALARY,
DATECHANGED = SYSDATE,
CHANGEDBY = 'SOME_USER';
END TRIGGER_UPDATED_EMPLOYEES;
Share and enjoy.
I got it working just correcting the UPDATE statements syntax and modifying the condition as #BobJarvis suggested, this is the final result:
CREATE TRIGGER trigger_updated_employees
AFTER UPDATE OF salary ON employees
FOR EACH ROW
when (old.salary <> new.salary)
BEGIN
UPDATE salaryAudit
SET (newsal, oldsal)
VALUES (:new.salary, :old.salary)
WHERE (salaryAudit.empid = old.empid);
UPDATE payroll
SET (salary)
VALUES (:new.salary)
WHERE (payroll.empid = old.empid);
END;
The concept is the same that #BobJarvis proposed but a lot simpler. Thanks