What is Foreign Key? What is the main difference between primary key and Foreig

What is Foreign Key?
What is the main difference between primary key and Foreign
Key ?
How Foreign Key can be defined?
Is Foreign key is used to join two or more table?

Question Posted / basawaraj b

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What is Foreign Key? What is the main difference between primary key and Foreign Key ? How Foreig..

Answer / sunil kumar

Foreign key represents the relationship between two tables.
A foreign key in a table whose value is derived from the
primary key from some other table.The table in which foreign
key is defined is called a foreign table or detailed table.
The table that defines the primary key and is referenced by
the foreign table is called primary table or master table.
Difference between primary key and foreign key is that
primary key must contain a value,must not contain null
value,redundant value and foreign key can contain redundant
value.
Foreign key is defined as= create table employee(empno int
not null,empname char(40)not null,dept char(20),foreign
key(dept)references department(deptno))
Yes Foreign key is used t join two or more tables.

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What is Foreign Key? What is the main difference between primary key and Foreign Key ? How Foreig..

Answer / amol kharat

Sunil is absolutely right.

foreign key may be null but primary key is not null, foeign
key is the reference to other table.

Foreign key is a primary key of reference table.

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0 No

What is Foreign Key? What is the main difference between primary key and Foreign Key ? How Foreig..

Answer / balaji ganesh doddi

Foreign key is establish the relationship between two
tables.
Primary key is used to uniqly identified by the data into a
table.
The major differences are
Primary key should not contain null values and redundant
value.
Foreign key can contain redundant value.

Foreign key is a primary key of reference table.

Foreign key is defined as= create table employee(empno int
not null,empname char(40)not null,dept char(20),foreign
key(dept)references department(deptno))
Yes Foreign key is used t join two or more tables.

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1 Yes

0 No

What is Foreign Key? What is the main difference between primary key and Foreign Key ? How Foreig..

Answer / guest

yes

Is This Answer Correct ?

0 Yes

4 No

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