Difference between primary key and unique key ?
- 77 Answers
- 197772 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 view?
How many categories of data types in oracle?
What is oracle datasource?
What are the built-in functions used for sending Parameters to forms ?
What is a tns file?
Give the different types of rollback segments.
What is the difference between translate and replace in oracle?
What is sequence?
Can any one explain me when i execute below query.. select months_between('07-JUL-12','10-FEB-12') from dual; Out put:- 4.90322581 How oracle calculate?
What is a table index in oracle?
An automatic job running via DBMS_JOB has failedKnowing only that its failed, how do you approach troubleshooting this issue?
How many types of cluster table in Oracle?
What are the system predefined user roles?
What is pragma autonomous transaction in oracle?
What is MTTR advisor in Oracle?
