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
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;
I've got 2 entities:
1) EMPLOYEES (Parent)
CREATE TABLE EMPLOYEES (
employee_id NUMBER (3) NOT NULL,
first_name VARCHAR (20) NOT NULL,
last_name VARCHAR (20) NOT NULL,
job_title VARCHAR (20) NOT NULL,
employee_type VARCHAR (1) NOT NULL,
salary NUMBER (5),
hourly_pay NUMBER (5,2),
bonus_pay NUMBER (5,2),
CONSTRAINT employee_pk PRIMARY KEY(employee_id));
2) EMPLOYEE_HISTORY (Child)
CREATE TABLE EMPLOYEE_HISTORY (
start_date DATE NOT NULL,
employee_id NUMBER (3) NOT NULL,
end_date DATE,
job_title VARCHAR (10) NOT NULL,
hourly_rate NUMBER (5,2) NOT NULL,
CONSTRAINT employee_history_pk PRIMARY KEY(start_date, employee_id));
I'm trying to create:
ALTER TABLE employee_history
ADD CONSTRAINT employee_history_fk
FOREIGN KEY (employee_id)
REFERENCES employee_history(employee_id);
When I do this, I get an error
ORA-02270: no matching unique or primary key for this column-list
My guess is that I cannot create the constraint on just employee_id because I have a composite key in my child table. I understand when an employee gets put into the database, the parent table is filled out and the "start date" should be filled out along with everything else. However, I do not understand how this would work if I had start_date in my parent table as well. I would be able to create my constraint, yes, but how will I be able to keep a record of changes in start_date if my start_date was inputted at the time of when the employee was entered into the database.I thought about using job_title as a primary key instead of start_date because it's present in both tables, but what happens when an employee gets promoted and demoted again? Won't a duplicate value constraint come up when the same employee_id and job_title is getting inserted?
Your references clause needs to reference the parent table. Not the child table
ALTER TABLE employee_history
ADD CONSTRAINT employee_history_fk
FOREIGN KEY (employee_id)
REFERENCES employee(employee_id); -- employee not employee_history
The SQL you posted is trying to create a self-referential foreign key where employee_history is both the parent and the child. That doesn't make sense in this case.
i didn't know what the problem is. First this one works fine in sql
create table Department
(Department_Id number(8) PRIMARY KEY ,
Dept_Name varchar(20),
Location varchar(20));
but the second one says missing right parenthesis ora-00907
create table Instructor(Instructor_ID number(8) PRIMARY KEY ,
Department_Id number(8) FOREIGN KEY REFERENCES Department(Department_Id) ,
Ins_name varchar2(20) ,
Position varchar(20) ,
email_Id varchar (40),
Contact_No number(10),
Date_Of_Joining date);
Leave out the FOREIGN KEY part:
Department_Id number(8) REFERENCES Department(Department_Id) ,
See Oracle FAQs for an example. The FOREIGN KEY keywords are for out-of-line constraints, which go after the column definitions.
I am trying to create a table with foreign key using oracle. My syntax is as follows
CREATE TABLE product (
product_id INT(7) NOT NULL,
supplier_id INT(7) NOT NULL,
product_name VARCHAR2(30),
product_price DOUBLE(4),
product_category VARCHAR2(30),
product_brand VARCHAR2(20),
product_expire DATE,
PRIMARY KEY (product_id),
FOREIGN KEY (supplier_id)
)
I got a error, saying
Error at Command Line:2 Column:14 Error report: SQL Error: ORA-00907:
missing right parenthesis
00907. 00000 - "missing right parenthesis"
*Cause:
*Action:
Please help!
Your foreign key should refference another column on another table.
Here is the documentation you need to fix your issue (how to write the query with the correct syntax for foreign key)
Also, change your data type for column product_price from DOULBE(4) to NUMBER(12,4).
You should not use limit for int type...oracle will take default length for int type .
Instead of int you can use Number type to make it run. And DOUBLE PRECISION is a data type in oracle but Double is not there. Also , syntax for foreign key is wrong.
so this query will work for sure :
CREATE TABLE product(
product_id number(7) NOT NULL,
supplier_id number(7) NOT NULL,
product_name VARCHAR2(30),
product_price DOUBLE PRECISION,
product_category VARCHAR2(30),
product_brand VARCHAR2(20),
product_expire DATE,
PRIMARY KEY (product_id),
FOREIGN KEY (supplier_id)
REFERENCES parent_table (supplier_id)
);
You create like foreign key references parent table that is the proper syntax for creating the foreign key
CREATE TABLE product(
product_id number(7) NOT NULL,
supplier_id number(7) NOT NULL,
product_name VARCHAR(30),
product_price DOUBLE PRECISION,
product_category VARCHAR(30),
product_brand VARCHAR(20),
product_expire DATE,
PRIMARY KEY (product_id),
FOREIGN KEY (supplier_id)
REFERENCES parent_table (supplier_id)
);
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;