Difference between primary key and unique key ?
Answer Posted / tom
There is two difference between them.
1. The not null constraint is by default added to primary
key, it means, primary key attribute cannot accept null
values, whereas, the attribute declared as unique can accept
null values. It is the major difference between the two.
2. Secondly, we can have only one primary key in a relation,
whereas, multiple attributes can be declared unique at the
same time.
Is This Answer Correct ? | 1 Yes | 0 No |
Post New Answer View All Answers
Can we commit inside a function in oracle?
Respected sir, Please send me technical questions related to oracle apps..
What is bulk copy or bcp in oracle?
Explain view?
Can we save images in a database and if yes, how?
What is dynamic proxy?
What is ASM (Automatic Storage Management) in Oracle?
What is oracle join syntax?
What are the uses of linked server and explain it in detail?
How do I spool in oracle?
Can the query output be sorted by multiple columns in oracle?
What is the difference between sharding and replication?
How to start instance with a minimal initialization parameter file?
Select all the employees who were hired in last 2 years and who works in dept where max managers are working.
How to initialize variables with default values?