Foreign Key creation in Oracle [duplicate] - sql

This question already has an answer here:
ORA-00907: missing right parenthesis
(1 answer)
Closed 8 years ago.
I tried to create Foreign key and PRIMARY KEY
My code is ok with Table1
CREATE TABLE Persons
(
P_Id int NOT NULL PRIMARY KEY,
LastName varchar(255) NOT NULL,
FirstName varchar(255),
Address varchar(255),
City varchar(255)
);
Table2:
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int FOREIGN KEY REFERENCES Persons(P_Id)
);
error :-ORA-00907: missing right parenthesis
Don't know what the error is.

When you declare the FK "inline" you must not specify the foreign key keyword:
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int REFERENCES Persons(P_Id)
);
Btw: you don't even need to list the column name when using an inline definition, P_Id int REFERENCES Persons would be enough.
That will generate a system-named constraint (e.g. SYS_C0066866), so it's generally better to use a format where you can specify the name of the constraint:
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int,
constraint fk_orders_person foreign key (p_id) REFERENCES Persons(P_Id)
);

If you're inlining your foreign key definition in the column's definition, you don't need the foreign key phrase:
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int REFERENCES Persons(P_Id)
);

For MySql
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int,
FOREIGN KEY(P_Id) REFERENCES Persons(P_Id)
);
For SQL
CREATE TABLE Orders
(
O_Id int NOT NULL PRIMARY KEY,
OrderNo int(10),
P_Id int FOREIGN KEY REFERENCES Persons(P_Id)
);
Check Manual

Related

There are no primary or candidate keys in the referenced table 'tblgender' that match the referencing column list in the foreign key 'giFK'

create database my_data
create table tblperson(
pid int primary key,
pname varchar(15),
pgender varchar(15)
)
create table tblgender(
gid varchar(15) primary key,
gender varchar(15)
)
Alter table tblperson add constraint giFK
Foreign key (pgender) references tblgender(gid)

Missing right parenthesis error in Oracle table

CREATE TABLE Countries
(CountryID INT NOT NULL PRIMARY KEY,
CountryName VARCHAR2(100) NOT NULL,
RegionID INT FOREIGN KEY REFERENCES Regions(RegionID)
);
keeps throwing me this:
ORA-00907: missing right parenthesis
What did I do wrong?
The inline foreign key syntax does not take a FOREIGN KEY keyword.
Consider:
CREATE TABLE Countries (
CountryID INT NOT NULL PRIMARY KEY,
CountryName VARCHAR2(100) NOT NULL,
RegionID INT REFERENCES Regions(RegionID)
);
Alternatively, you can declare the foreign key on another line, like so:
CREATE TABLE Countries (
CountryID INT NOT NULL PRIMARY KEY,
CountryName VARCHAR2(100) NOT NULL,
RegionID INT,
CONSTRAINT fkRegionID FOREIGN KEY (RegionID) REFERENCES Regions(RegionID)
);
This works as well:
CREATE TABLE Countries (
CountryID INT NOT NULL PRIMARY KEY,
CountryName VARCHAR2(100) NOT NULL,
RegionID INT,
FOREIGN KEY (RegionID) REFERENCES Regions(RegionID)
);
Demo on DB Fiddle

ERROR: there is no unique constraint matching given keys for referenced table

I am getting an error when i create my tabels.
The problem is that AssCode is not unique, so i can set it to unique, the combination of courseCode and AssCode is unique, thats why they are set as primary keys. I am using postgressql
here is the error:
ERROR: there is no unique constraint matching given keys for referenced table "assignments"
SQL state: 42830
here is my code:
CREATE TABLE Teachers (
BSN int primary key,
Surname varchar(40) NOT NULL,
Name varchar(40) NOT NULL
);
CREATE TABLE Courses (
CourseCode varchar(10) primary key,
Name varchar(20) NOT NULL
);
CREATE TABLE Assignments (
CourseCode varchar(10) REFERENCES Courses ON DELETE CASCADE,
AssCode varchar(10),
primary key(CourseCode,AssCode),
DependOn varchar(10),
Year date,
week int
);
CREATE TABLE WorkOn (
BSN int REFERENCES Teachers(BSN),
CourseCode varchar(10) REFERENCES Assignments(CourseCode),
AssCode varchar(10) REFERENCES Assignments(AssCode),
primary key (CourseCode,BSN,AssCode)
);
I found the answer:
CREATE TABLE WorkOn (
BSN int primary key REFERENCES Teachers(BSN),
CourseCode varchar(10),
AssCode varchar(10),
foreign key (CourseCode, AssCode) references Assignments (CourseCode, AssCode)
);

create procedure to delete child table data if parent data is deleted

create table a (
a_id integer,
a_name varchar2(10),
PRIMARY KEY (a_id)
)
create table b(
b_id,
b_name varchar2(10),
a_id integer,
PRIMARY KEY (a_id),
FOREIGN KEY (a_id) REFERENCES a(a_id)
)
If the children have FKs linking them to the parent, then you can use DELETE CASCADE on the parent.
CREATE TABLE book
( book_id int not null,
book_name varchar(50) not null,
CONSTRAINT book_pk PRIMARY KEY (book_id)
);
CREATE TABLE bookdetails
( detail_id int not null,
book_id int not null,
CONSTRAINT fk_book
FOREIGN KEY (book_id)
REFERENCES book(book_id)
ON DELETE CASCADE
);
Complete Procedure as you required just change the tables name in procedure
visit https://anzblog.com/2017/04/29/create-procedure-delete-child-table-data-parent-data-deleted/
It will work for you.As per my understanding.

Sturctured Query Language

create table customer(
custno number(10) constraint foo primary key,
custname character(15),
city character(15),
phone number(10));
create table invoice(
invo number(10) constraint inv primary key,
invdate date(10),
constarint c references customer(custno));
I cannot able to create the second table and am having doubt of the data type date and If I neglected that attribute(invdate) still I cannot able to create the second table.Reason please.
create table customer
( custno int constraint foo primary key
,custname character(15)
,city character(15)
,phone int
)
go
create table invoice
( invo int constraint inv primary key
constraint ck references customer(custno)
,invdate date
)