Difference between primary key and unique key ?
Answer Posted / rinu
1)unique key can be null but primariy key cant be null.
2)primariy key can be refrenced to other table as FK.
3)we can have multiple unique key in a table but PK is one
and only one.
4)PK in itself is unique key.
5)a table can have more then one unique key column but a
table can have only one primary key column.
6)primary key creates clustered index but unique key
creates non clustered index.
| Is This Answer Correct ? | 12 Yes | 7 No |
Post New Answer View All Answers
State and explain the different types of data models?
Explain oracle’s system global area (sga).
How to write a query with a right outer join in oracle?
How to select some columns from a table in oracle?
What is the scope of a local variable?
How to use "in out" parameter properly?
How oracle handles dead locks?
How to select all columns of all rows from a table in oracle?
List out the types of joins.
What is the data type of dual table?
How to increment dates by 1 in oracle?
How to display row numbers with the records?
Can I create users through internet explorer in oracle 10g?
What are the limitations of check constraint?
Is truncate autocommit in oracle?