Answer / anil bharodiya

Primary key is field of the table that can be used to
uniquely identify records of the table

Answer / sripathi venkata ramesh

I am Sripathi Venkata Ramesh from Gudivada and the answer
is mentioned below

Primary key: A Primary key is a column or group of columns
used to uniquely identify each row in a table like
It defines the column as a Mandatory column.
The data held across the column must be unique.
By default it creates clustered index.
It does not allow null values and duplicate values

Foreign key: A Foreign key is a column or group of columns
whose values are derived from the primary key of some other
table

Answer / bharathi sundar

A PRIMARY KEY DOES NOT ACCEDES DUPLICATIONS .
A FOREIGN KEY IS USED FOR LINKING TWO DATABASE TABLES
ABSTRUSELY .

A FOREIGN KEY USES THE PRIMARY KEY IN ANOTHER TABLE,
TO RETRIEVE OR TO IDENTIFY THE CELL VALUES IN ANOTHER
TABLE.........

Answer / o p yadav

primary key is the unique value,but its not nul values..
this kry is avoided dublicate values

foreign key is always references the primary key and allow null value.

Answer / sravan kumar

A attribute which it is uniquely identifies in a row in a
table is called Primary key..


A column in a table whose values matches the primary key in
some other table is called Foreign key

Answer / raja

foriegn key always refers to
primary key but Primary key is unique key

Answer / suneel manne

Primary key is a key it will allow only Unique values and
avoid duplicate values and foreign key is a reference key
from the other table, So here primary key acts as a parent
key and foreign key acts as a child key.

Answer / ibrahim

A primary key is an combination of attributes that uniquely
identifies each row in a relation. A primary key is
designated by underlining the attribute name. The primary
key of an entity set allows us to distinguish among the
various entities of the set.

A foreign key is an attribute in a relation of database
that serves as the primary key of another relation in the
same database.

Answer / kush kaushik

Primary key is primary means from india and foreign key is forgeiner means from forign .. ..By kush kaushik(kush.kaushik87@gmail.com)

Answer / reddy

foreign key is NULL
foreign key reference as Primary key in another table


Primary key is unique
primary key is not NULL and

How to display the hierarchy of employee and managers without using connect by prior.

1 Answers  

Explain what are the advantages of views?

0 Answers  

Where is the export dump file located?

0 Answers  

how can we write trigger in trigger???????? can we write one trigger on two table???

2 Answers   Value Labs,

What is COST-based approach to optimization ?

5 Answers  

Name the various constraints used in oracle?

0 Answers  

while i take backup using ibm tsm the following errors occurred: rman-03009 ora-19513 ora-27206 ora-19502 ora-27030 ora-ora19511

0 Answers  

Why does for update in oracle 8 cause an ora-01002 error?

0 Answers  

HOW TO CONVERT ORACLE TABLE DATA (RECORDS)INTO EXCEL SHEEET?

3 Answers  

Explain the use of full option in exp command.

0 Answers  

What is the difference between translate and replace in oracle?

0 Answers  

How view is different from a table?

0 Answers