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 implicit cursor in dbms?
What is stored in a database?
Where is database data stored?
What are the disadvantages of a query?
What is a sequence in a database?
Is there some bulk load or other way to import a lot of data fast?
What do you understand by database triggers?
What is vacuum in database?
What is order by clause?
Explain data independence?
Operators used in select statements are?
Define view, sequence and index in DBMS.
Why rdbms is not suitable for big data?
What is the structure of a database?
State some commands of ddl in dbms?