Interested to Buy Any Domain ? << Click Here >> for more details...
Difference between primary key and unique key ?
- 77 Answers
- 210045 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 / sunil upadhyay
the basic difference is that primary key can not have null
value whereas Unique key can have null values.two null
value are not same.One table may have more than one Unique
Key Constraint
columns, but should have only one Primary Key Constraint
column.
| Is This Answer Correct ? | 88 Yes | 51 No |
Post New Answer View All Answers
Explain how you would restore a database using RMAN to Point in Time?
What is index in Oracle?
How is it different from a normal table?
What is the difference between I and G in Oracle?
What is difference between sid and service name in oracle?
Is oracle a relational database?
what is the scenario where you take the database to NoArchivelog mode?
Explain the difference between a procedure and a function? What do you understand by those terms?
How to specify default values in insert statement using oracle?
Can sub procedure/function be called recursively?
What is recycle bin in Oracle?
What is tns entry?
Why do you create or replace procedures rather that drop and recreate.
How to define a specific record type?
How many memory layers are in the oracle shared pool?
