How to use Foreign Key in SQL?

In this article, we will figure out how A FOREIGN KEY in one table focuses to a PRIMARY KEY in another table?

Fundamentally, Foreign Key speaks to connection between tables.


    column-name data_type (size) CONSTRAINT constraint-name  
    References  Table-name (Column-name)


Table 1:

How to use Foreign Key in SQL?

Table 2:

How to use Foreign Key in SQL?

First create a primary key in first table which is also called unique key.

Like this:

create table student 
(enroll number(6) primary key, s_name varchar(25), address varchar2(20), 
contact number(10) );

Second create foreign key by using second table.

Like this:

create table student_fees
(enroll number(6) constraint en_fk References Student (enroll) , course_fee number(8), 
status varchar2(6), amount number(10) );
How to use Foreign Key in SQL?


In this article, we have figured out how to utilize outside key and how it functions and valuable for us to recover information from the social database? I trust you comprehend the idea; in the event that you have any question, don’t hesitate to ask in the remark area.

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