what is difference between "Primary key" and "Unique key"?
Answer Posted / nitin gupta
Uniques: Enforce unique data in the database
it allows row containing null value but only once
It implements non clustered index.
primary key: Enforce unique data in the database
it don't allow any record containing null value
it implements clustered index (data physically
sorted)
| Is This Answer Correct ? | 3 Yes | 0 No |
Post New Answer View All Answers
Can we use views in stored procedure?
Why do we use joins?
When can we use the where clause and the having clause?
Can cursors be part of a trigger body?
what are the nonstandard string types? : Sql dba
What are sql*plus environment variables?
Are views faster than queries?
How do I count rows in sql?
What is synchronized subquery?
Why do we need unique key in a table?
How to pipe multiline string to isql?
How to display Row Number with Records in Oracle SQL Plus?
Does view store data in sql?
Explain some predefined exceptions.
what are date and time functions in mysql? : Sql dba