what is the difference between unique and primary key
Answer Posted / divyarao
primary key accepts only values which has no duplication ,and does not accept null values . for a a table there should be only one primary key constraint.
whereas in unique key ,it accepts null values .here also there should not be any duplication ,a table may have more than one unique key constarint
Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What is the purpose of a model?
How do I keep my database up to date?
What does rdbms stand for?
What is a hierarchical database?
Explain concurrency transparency.
How do you delete a table from database?
How we can connect the Webform pages with database?
What is index and also explain types of indexing in dbms?
How to recreate the index on a firebird table?
Differentiate table scan from index scan.
What is the main purpose of database?
What do you mean by Checkbox ?
What is pdo in database?
What are rdbms concepts?
What are the advantages of dbms?