Difference between primary key and unique key ?
- 77 Answers
- 199356 Views
- Accenture, B2B Software Technologies, Cognizant, HP Finsoft, IndiaNIC, Karomi Technology, Keane India Ltd, L&T, Onward eServices, R Systems, Shakti, Techtic Solutions, I also Faced
- E-Mail Answers
Answer Posted / sikander
Primary key does not allow null value but unique key allows
null value. suppose tableA two column : columnB & columnC .
where coulmnB is primary key & columnC is unique key.
If we insert null value in columnB.It will not accept
columnB but columnC
| Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
Explain the blob datatype?
What is a proxy class?
What is oracle used for?
Explain joins in oracle?
How to write text literals in oracle?
How to calculate date and time differences in oracle?
What is an oracle user account?
What are the differences between date and timestamp in oracle?
Which dictionary view(s) would you first look at to understand or get a high-level idea of a given Advanced Replication environment?
What is meant by joins? List out the types of joins.
How to create a new tablespace in oracle?
What is the difference between truncate & delete command?
How to use existing values in update statements using oracle?
What is a trigger and what are its types in oracle?
How would you best determine why your MVIEW couldnt FAST REFRESH?
