what is the difference between unique and primary key

Answer Posted / ravi kanth

Primary key is the combination of unique and not null.But
unique key accepts null values also.

Is This Answer Correct ?    6 Yes 1 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is data management process?

585


1)How to check tablespace utilization? 2)what are the RMAN CLONING STEPS? 3)what is standby database? 4)what is difference between standalone database and target database? 5)How to backup the standalone database? 6)tell about the ubgrade steps? 7)How to apply the pathes?

1881


Write about Transaction Management in Oracle 9i?

1735


Is declare cursor executable?

607


What is create database?

514






1. What is Container? 2. Tell me about your project? 3. Which container you are used in your project? 4. What is Surrogate key? 5. How you are implemented it? 6. Difference between Server job and Parallel job? 7. What is your Target Database? 8. What is Source System? 9. Difference between Join and Lookup? 10. Are you maintaining historical data? What is the logic used to maintained to historical data? 11. Do you have documents for mapping?

1426


What do you understand by clause in sql?

600


How to detect applications and users that hold transactions open too long?

553


What is acid property in dbms?

606


define aggregate functions.

603


What are the lock types?

605


What are databases what are the uses of databases?

537


Discuss some of the techniques that can be used to tune operational performance.

607


Define entity.

630


What are the advantages of database management system?

536