what is the difference between unique and primary key
- 5 Answers
- 4412 Views
- I also Faced
- E-Mail Answers
Answer Posted / suresh kumar somayajula
Unique Key allows NULL value and a table can have more than
one UNIQUE KEY Constraint.
Primary Key is the combination of UNIQUE+NOT NULL,means it
won't allow NULL Values and a table can have only one
Primary Key.But a table can have Composite Primary Key.
Thank you,
Suresh
| Is This Answer Correct ? | 4 Yes | 0 No |
Post New Answer View All Answers
How to use events with zebedee, ssh or stunnel?
What types of questions are asked in NIC(Natinal Informatics Centre)'s interview?If any one has any information about this,I would be very thankful to him/her.....
How can you perform pattern matching in sql?
What are the differences between drop, truncate and delete commands?
What is a form used for in a database?
What is the purpose of queries in a database?
What is n tier architecture in dbms?
What are the different types of keys in the database?
What are the database skills?
Why do we need database?
Explain the functionality of dml compiler.
What is a candidate key in dbms?
What is the largest component of a database?
What are cursors give different types of cursors?
What is 2-tier architecture?
