Interested to Buy Any Domain ? << Click Here >> for more details...
Define the terms primary key foreign key and also the
difference between primary and the unique key
- 2 Answers
- 11216 Views
- I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / pugal
Primary Key : The primary key of a relational table
uniquely identifies each record in the table
Foreign Key : These keys are used to create relationships
between tables.
Unique Key : In relational database design, a unique key is
a candidate key to uniquely identify each row in a table. A
unique key comprises a single column or set of columns
Difference between primary and unique key :
primary key not allows null values
unique key allows null values
| Is This Answer Correct ? | 33 Yes | 12 No |
Answer / nithya
one more difference is:
a table can have only one primary key but many unique keys.
| Is This Answer Correct ? | 22 Yes | 3 No |
Can a property clause itself be based on a property clause ?
How to view the data files in the current database?
What is a subquery?
you are a universe designer and report developer in BO, what type of information you gather from client?Briefly explain plz
What is a nvl function?
How to speed up webrick?
Which is faster join or subquery in oracle?
How to list all indexes in your schema?
what are different types of deletes?
Explain cascading triggers.
How to assign values to variables?
How to write a query with a full outer join in oracle?
Oracle General 
