what is primary key,unique key, foreign key? can u teach me
in simple language?
Answer Posted / uma maheswari
primary key:
IT IS THE MAIN KEY AND IT DOES NOT ALLOWS THE NULL VALUE...
Unique key:
IT IS SIMILAR TO PRIMARY KEY .IT ALSO DONT ALLOWS THE NULL VALUE.
foreign key:
IT IS USED TO REPRESENT THE PRIMARY KEY VALUE...
| Is This Answer Correct ? | 1 Yes | 1 No |
Post New Answer View All Answers
Explain database partitioning.
Source File: Target EMPNO, SAL Empno, Format 101, 1000 101, 1000 101, 1100 101, 1000, 1100 101, 1000 101, 1000, 1100, 1000 101, 10000 101, 1000, 1100, 1000, 10000 102, 1100 102, 1100 102, 1300 102, 1100, 1300 102, 1200 102, 1100, 1300, 1200 102, 1500 102, 1100, 1300, 1200, 1500 How can i get that output using datastage(ETL) tool
What are different types of clusters present?
What is a Database?
When should you not use firebase?
List the properties of a transaction.
How does database replication work?
How many types of normalization? What is the use of it?
What is the use of default key?
List some advantages of dbms.
Write a query to get maximum and second maximum in oracle?
define primary key index, bitmap index, hash index,virtual indwx
What is a sequence? Explain it with one example?
Hi, I want do a course in DWH Informatica Administrator and Abinito Administrator please tell me some institute in chennai and i am searching for a job,so please help me and my mail id : satty_rh@yahoo.co.in Thanks, Kumar
Explain entity set?