Having hard time with creating a trigger. Here is my code. I create 2 tables:
CREATE TABLE client_table
(
clientid NUMBER(6) PRIMARY KEY,
lastname varchar2(50) NOT NULL,
firstname varchar2(50) NOT NULL,
password varchar2(20) NOT NULL,
email varchar2(100) NOT NULL,
phoneno NUMBER(12) NOT NULL,
zipcode NUMBER(6) NOT NULL ,
street varchar2(60) NOT NULL,
CHECK (email LIKE '%#%.%')
);
CREATE TABLE location_table
(
zipcode NUMBER(6) PRIMARY KEY,
country varchar2(100) NOT NULL,
region varchar2(60) NOT NULL,
town varchar2(60) NOT NULL
);
I add a constraint so that zipcode in client_table is a foreign key.
ALTER TABLE client_table
ADD CONSTRAINT clirefzip
FOREIGN KEY(zipcode) REFERENCES location_table(zipcode)
DEFERRABLE INITIALLY DEFERRED;
Now I want to add a trigger, so that when i delete a location from location_table, it will delete all clients from client_table, that have the same zipcode as the location deleted. So I try something like this:
CREATE OR REPLACE TRIGGER location_delete
AFTER DELETE ON location_table
REFERENCING OLD AS old_buffer
FOR EACH ROW
DELETE FROM client_table WHERE zipcode = old_buffer.zipcode;
Unfortunately it does not work.
Hi there has some syntactical errors in your code. I hope this code works . Thanks
CREATE OR REPLACE TRIGGER location_delete
AFTER DELETE ON location_table
--REFERENCING OLD AS old_buffer
FOR EACH ROW
begin
DELETE FROM client_table WHERE zipcode = zipcode;
end location_trigger;
Related
I am trying to create a trigger in Oracle whereby we move deleted records to another table. So when deleted column is set to 1, it should move the records from the patient_table to the deleted_patient_table.
Can you please help :)
CREATE TABLE Patient_Table(
PatientID NUMBER(6) Primary Key,
Title char(4) NOT NULL,
Forename varchar2(20) NOT NULL,
Surname varchar2(20) NOT NULL,
Gender char(1) NOT NULL CHECK (Gender in ('M','F')),
DOB date NOT NULL,
TelNo varchar(12) NOT NULL,
Conditions varchar(200) NOT NULL,
Deleted Number(1) NOT NULL CHECK (Deleted in ('0','1'));
-- Table that should contain deleted records --
Create Table Deleted_Patient_table(
PatientID NUMBER(6) Primary Key,
Title char(4) NOT NULL,
Forename varchar2(20) NOT NULL,
Surname varchar2(20) NOT NULL,
Gender char(1) NOT NULL CHECK (Gender in ('M','F')),
DOB date NOT NULL,
TelNo varchar(12) NOT NULL,
Conditions varchar(200) NOT NULL,
Deleted Number(1));
Create or replace trigger trg_del
Before delete on Patient_Table
for each row
Begin
Insert into Deleted_Patient_table value (:old.PatientID,...)
End;
It seems you're soft-deleting your rows. i.e. not deleting but updating related column(Deleted) from 0 to 1. The values of column can be one of two and not null, so you only need to compare only two values of them without nvl operator. During this update operation you can use below trigger to produce log records :
Create or Replace Trigger Trg_Del_Patient
After Update on Patient_Table
For Each Row
Begin
If ( :old.Deleted = 0 and :new.Deleted = 1 ) Then
Insert into Deleted_Patient_table
values(:old.PatientID,:old.Title,:old.Forename,:old.Surname,
:old.Gender,:old.DOB,:old.TelNo,:old.Conditions);
Delete Patient_Table where PatientID = :old.PatientID;
-- Include this Delete statement, if you want to remove after the row has been inserted to the Deleted_Patient_Table
End If;
End;
while making foreign key in player table it shows following error
ORA-02270: no matching unique or primary key for this column-list
create table person
(
per_ssn number(10) not null,
per_name varchar2(30) not null,
CONSTRAINT pk_PersonID PRIMARY KEY (per_ssn,per_name)
);
create table Player
(
player_ssn number(10) not null,
player_name varchar2(30) not null,
football_club_name varchar2(30) not null,
p_age number(2) not null,
p_weight number(3) not null,
p_height number(10) not null,
country varchar2(20) not null,
p_starting_date date not null,
p_ending_date date not null
);
alter table Player
add constraint player_ssn
FOREIGN KEY (player_ssn)
REFERENCING person (per_ssn)on delete cascade
I want to make two primary keys in person table and then want to refer these
primary keys in player table.
If I make one primary key and then refer it in player table, then it does not show error but I want to make two primary keys.
You should be referencing per_ssn,per_name because that is your PK on person.
Anyway, think about making per_ssn your PK in person table
alter table Player
add constraint player_ssn
FOREIGN KEY (player_ssn,player_name)
REFERENCING person (per_ssn,per_name)on delete cascade
I am trying to write my first table create script with column definitions. I have tried several things to get this error to go away, but to no avail. Please take a look to see if their is anything obvious in my code below:
CREATE TABLE CD_TYPE (
CD_TYPE VARCHAR2(4) PRIMARY KEY,
CD_FORMAT VARCHAR2(10)
);
CREATE TABLE MANUFACTURER (
MANUFACTURER_NUM NUMBER(3) PRIMARY KEY,
MANUFACTURER_NAME VARCHAR2(30)
);
CREATE TABLE CD_TITLE (
CD_NUM NUMBER(4) PRIMARY KEY,
TITLE VARCHAR2(30),
MANUFACTURER_NUM VARCHAR2(30) FOREIGN KEY,
CD_TYPE VARCHAR2(4) FOREIGN KEY,
ACQUIRED_DATE DATE,
ORIGINAL CHAR(1)
);
CREATE TABLE CD_SN (
CD_NUM NUMBER(4) PRIMARY KEY FOREIGN KEY,
SERIAL_NUM VARCHAR2(30) PRIMARY KEY,
NUM_LIC_REMAIN NUMBER(2)
);
The problem is with the columns reading
MANUFACTURER_NUM VARCHAR2(30) FOREIGN KEY,
You forgot to specify what table these columns refer to.
You to that with a REFERENCES clause:
create table cd_title (
cd_num number(4) primary key,
title varchar2(30),
manufacturer_num REFERENCES MANUFACTURER,
cd_type REFERENCES CD_TYPE,
acquired_date date,
original char(1)
);
Alternatively, you can specify the name for the foreign key with a CONSTRAINT ... FOREIGN KEY (...) REFERENCES ... clause:
create table cd_title (
cd_num number(4) primary key,
title varchar2(30),
manufacturer_num,
cd_type,
acquired_date date,
original char(1),
--
CONSTRAINT cd_title_fk1 FOREIGN KEY (manufacturer_num) REFERENCES manufacturer,
CONSTRAINT cd_title_fk2 FOREIGN KEY (cd_type ) REFERENCES cd_type
)
I am new to oracle,
I have created two tables using following queries,
CREATE TABLE employee
(
emp_name VARCHAR(20) NOT NULL,
street VARCHAR(50) NOT NULL,
city VARCHAR(20) NOT NULL,
PRIMARY KEY(emp_name)
)
and
CREATE TABLE company
(
comp_name VARCHAR(20) NOT NULL,
city VARCHAR(20) NOT NULL,
PRIMARY KEY(comp_name)
)
Now I am trying to create another table using some foreign keys,
CREATE TABLE works
(
emp_name varchar(20) NOT NULL,
comp_name varchar(20) NOT NULL,
salary int(10) NOT NULL,
FOREIGN KEY(emp_name) REFERENCES employee(emp_name),
FOREIGN KEY(comp_name) REFERENCES company(comp_name)
)
Getting ERROR : ORA-00907: missing right parenthesis
I have also tried with
CREATE TABLE works
(
emp_name varchar(20) NOT NULL,
comp_name varchar(20) NOT NULL,
salary int(10) NOT NULL,
constraint wemployee FOREIGN KEY(emp_name) REFERENCES employee(emp_name),
constraint wcompany FOREIGN KEY(comp_name) REFERENCES company(comp_name)
)
But getting same error.
Can any one tell me that where I am doing mistake?
I'm no expert in oracle, but are you allowed to specify the (10) in salary int(10) NOT NULL?
1: you should have a table called "test" with two columns, id and testdata. (This is just a dumb quick example, so I won't bother to specify any constraints on id.)
create table test (id number, testdata varchar2(255));
2: Next we'll create a sequence to use for the id numbers in our test table.
create sequence test_seq
start with 1
increment by 1
nomaxvalue;
You could change "start with 1" to any number you want to begin with (e.g. if you already have 213 entries in a table and you want to begin using this for your 214th entry, replace with "start with 214"). The "increment by 1" clause is the default, so you could omit it. You could also replace it with "increment by n" if you want it to skip n-1 numbers between id numbers. The "nomaxvalue" tells it to keep incrementing forever as opposed to resetting at some point.i (I'm sure Oracle has some limitation on how big it can get, but I don't know what that limit is).
3: Now we're ready to create the trigger that will automatically insert the next number from the sequence into the id column.
create trigger test_trigger
before insert on test
for each row beginselect test_seq.nextval into :new.id from dual;
end;
/
There are two different ways to create a table with constraints:
1)
create table department(
deptno number(5) primary key,
deptname varchar2(30),
empno number(5) references emp(empno));
2)
create table department(
deptno number(5),
deptname varchar2(30),
empno number(5),
constraint pkey_deptno primary key(deptno),
constraint fkey_empno foreign key(empno) references Emp(empno));
When creating the index inline with the rest of the table creation statement try dropping the FOREIGN KEY part:
CREATE TABLE works
(
emp_name varchar(20) NOT NULL,
comp_name varchar(20) NOT NULL,
salary int(10) NOT NULL,
emp_name REFERENCES employee(emp_name),
comp_name REFERENCES company(comp_name)
)
See this question for more details:
ORA-00907: missing right parenthesis
So this is from a uni coursework and is my first time working with Oracle (and using triggers). We are supposed to be creating a database for an airlines.
Part of the database is
CREATE TABLE FLIGHT_BOOKING (
BOOKING_ID NUMBER(11) PRIMARY KEY,
BOOKING_TIME DATE NOT NULL,
EMPLOYEE_ID NUMBER(11) NOT NULL,
FLIGHT_ID NUMBER(11) NOT NULL,
TOTAL_COST NUMBER(4,2) NOT NULL
);
CREATE TABLE FLIGHT (
FLIGHT_ID NUMBER(11) PRIMARY KEY,
PLANE_ID NUMBER(11) NOT NULL,
START_ID NUMBER(11) NOT NULL,
DESTINATION_ID NUMBER(11) NOT NULL,
TRANSIT_ID NUMBER(11),
DEPARTURE_TIME DATE NOT NULL,
ARRIVAL_TIME DATE NOT NULL,
NUM_BOOKED NUMBER (4) NOT NULL
);
CREATE TABLE PASSENGER (
PASSENGER_ID NUMBER(11) PRIMARY KEY,
FIRST_NAME VARCHAR2(20) NOT NULL,
MIDDLE_NAME VARCHAR2(20) NULL,
LAST_NAME VARCHAR2(20) NOT NULL,
TELEPHONE NUMBER(11) NOT NULL,
BOOKING_ID NUMBER(11) NOT NULL
);
So what I want to do is create a trigger such that every time a new passenger is added to the PASSENGER table, the trigger finds the corresponding FLIGHT_ID from the FLIGHT_BOOKING table and increments NUM_BOOKED for the corresponding flight in the FLIGHT table.
I have tried going through the oracle documentation, but i could not find anything that describes a situation where two or more tables are concerned.
Any help would be really appreciated!
you can do it like this:
CREATE OR REPLACE TRIGGER update_flight_booking_info
AFTER INSERT ON PASSENGER
FOR EACH ROW
DECLARE
v_flight_id number;
v_booking_id number;
BEGIN
v_booking_id := :new.booking_id ;
select flight_id into v_flight_id
from flight_booking
where booking_id = v_booking_id;
update flight
set NUM_BOOKED = NUM_BOOKED + 1
where flight_id = v_flight_id;
END;
HTH.
I'd rather not store that number, and calculate it as needed, but okay, it is just course material. :)
When you create a trigger, inside it you can put all kinds of code, including update statements.
So you can write a trigger like this:
create or replace trigger TIDB_BOOKING
before insert or delete
for each row
declare
V_Increment int;
begin
-- Inc or dec, depending on insert or update.
-- Hasn't a booking got a number of seats?
-- Also, can bookings be updated/moved to other flights?
-- These problems aren't yet taken into account in this code.
V_Increment := 1;
if deleting then
V_Increment := -1;
update FLIGHT f
set f.NUM_BOOKED = f.NUM_BOOKED + V_Increment
where f.FLIGHT_ID = nvl(:new.FLIGHT_ID, :old.FLIGHT_ID);
end;