what is primary key,unique key, foreign key? can u teach me
in simple language?

Answer Posted / patel gopikumar

PRIMARY KEY : it is a key that not allow null value in database tables field....

UNIQUE KEY : it is a key that store or manage data uniquely...

FOREIGN KEY : it is key that use is...connect two fields in the different tables........with foreign key......


thnks........

s-150907-007 PATEL GOPIKUMAR

Is This Answer Correct ?    5 Yes 12 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is Object Oriented model?

793


What is redis good for?

746


How to do Stored procedure testing? Who does this testing (Developer or tester)?

1583


How many types of locks are present in a database?

803


aht is the difference b/w network & hierarchial & relational dbms????

1976


What is replicaset?

754


Why merge statement is used inside the database?

845


issues involved in modeling and building data werahouses

1733


How default key is different from primary key?

806


Differentiate between unique key and foreign key?

772


What is the difference between oracle and MS Access?

815


Is hive a database?

719


How much does it cost to build a database?

755


Please post the scenerois for writing the complex sql queries , for my practice.Can be any query if you cannot solve.

2298


What is the purpose of TNS?

798